Chapter 15 - Cardiovascular System 7.txt
What does the prefix 'angio-' refer to?; Vessel What is angiotensin?; A substance that constricts blood vessels. What does the prefix 'ather-' refer to?; Porridge What is atherosclerosis?; Deposits of plaque in arteries. What does the prefix 'brady-' refer to?; Slow What is bradycardia?; Abnormally slow heartbeat. What does the prefix 'diastol-' refer to?; Dilation What is diastolic pressure?; Blood pressure when the ventricle of the heart is relaxed. What does the prefix 'edem-' refer to?; Swelling What is edema?; Accumulation of fluids in the tissues that causes them to swell. What does the suffix '-gram' refer to?; Something written What is an electrocardiogram?; Recording of the electrical changes in the myocardium during a cardiac cycle. What does the prefix 'lun-' refer to?; Moon What is a semilunar valve?; A valve with crescent-shaped flaps. What does the prefix 'myo-' refer to?; Muscle What is the myocardium?; Muscle tissue within the wall of the heart. What does the prefix 'papill-' refer to?; Nipple What is a papillary muscle?; A small mound of muscle projecting into a ventricle of the heart. What does the prefix 'phleb-' refer to?; Vein What is phlebitis?; Inflammation of a vein. What does the prefix 'scler-' refer to?; Hard What is arteriosclerosis?; Loss of elasticity and hardening of a blood vessel wall. What does the prefix 'syn-' refer to?; Together What is a syncytium?; A mass of merging cells that act together. What does the prefix 'systol-' refer to?; Contraction What is systolic pressure?; Blood pressure resulting from a single ventricular contraction. What does the prefix 'tachy-' refer to?; Rapid What is tachycardia?; Abnormally fast heartbeat. How many liters of blood does the heart pump through the body each day?; 7,000 liters. How many times does the heart contract in an average lifetime?; 2.5 billion times. In what order does the heart pump blood through the blood vessels?; Arteries → arterioles → capillaries → venules → veins → back to heart. What makes up the cardiovascular system?; The heart and all blood vessels. What does the term 'cardiovascular' refer to?; Both heart and blood vessels. What is the function of the heart's pumping action?; To transport blood through blood vessels. How many circuits do blood vessels form in the cardiovascular system?; Two circuits. What is the function of the pulmonary circuit?; To transport oxygen-poor blood from the heart to the lungs and back to the heart. What happens to the blood in the lungs during the pulmonary circuit?; Blood picks up O2 and drops off CO2. What is the function of the systemic circuit?; To transport oxygen-rich blood from the heart to all body cells and back to the heart. What does the blood deliver to cells in the systemic circuit?; Nutrients. What does the blood remove from cells in the systemic circuit?; Wastes. What type of blood does the left side of the heart contain?; Oxygen-rich blood. What type of blood does the right side of the heart contain?; Oxygen-poor blood. What are the two circuits through which blood runs?; Pulmonary circuit to lungs and systemic circuit to body cells. Where does the pulmonary circuit transport blood?; To the lungs. Where does the systemic circuit transport blood?; To body cells. What shape is the heart?; Hollow, cone-shaped. Where is the heart located?; In the mediastinum of the thoracic cavity, superior to the diaphragm. How many chambers does the heart have?; 4 chambers. What are the upper chambers of the heart called?; Atria. What are the lower chambers of the heart called?; Ventricles. What is the function of the ventricles?; Pumping action. How does heart size vary?; Heart size varies with body size. Where does the heart lie in the body?; The heart lies in the thoracic cavity. What is the average size of the heart?; The average size of the heart is 14 cm long and 9 cm wide. Where is the heart located in relation to the sternum?; The heart is located posterior to the sternum. Where is the heart located in relation to the lungs?; The heart is located medial to the lungs. Where is the heart located in relation to the vertebral column?; The heart is located anterior to the vertebral column. Where does the base of the heart lie?; The base of the heart lies beneath the 2nd rib. Where does the apex of the heart lie?; The apex of the heart lies at the 5th intercostal space. Where is the heart located in the human body?; The heart is located in the thoracic cavity, between the lungs, and behind the sternum. What structure is directly in front of the heart?; The sternum. What is the name of the lower pointed end of the heart?; The apex of the heart. What is the name of the upper part of the heart?; The base of the heart. What structure lies directly below the heart?; The diaphragm. What is the pericardium?; A covering over the heart and large blood vessels. What is the fibrous pericardium?; The outer layer that surrounds the double-layered serous membrane. Where is the parietal pericardium located?; Deep to the fibrous pericardium; it is the outer layer of the serous membrane. What is the visceral pericardium also known as?; The epicardium. What is the function of the visceral pericardium?; It is the inner layer of the serous membrane and is attached to the surface of the heart. What are the three distinct layers of the heart wall?; Epicardium, Myocardium, and Endocardium. What is another name for the epicardium?; Visceral pericardium. Which layer of the heart wall is the outer layer?; Epicardium. Which layer of the heart wall is the middle layer?; Myocardium. Which layer of the heart wall is the inner layer?; Endocardium. What type of tissue composes the myocardium?; Cardiac muscle tissue. Which layer of the heart wall is the thickest?; Myocardium. What does the endocardium form?; The inner lining of all heart chambers. Which layer of the heart wall is described as a thin layer?; Both the epicardium and endocardium are thin layers. What is the composition of the epicardium (visceral pericardium)?; Serous membrane of connective tissue covered with epithelium and including blood capillaries, lymph capillaries, and nerve fibers. What is the function of the epicardium (visceral pericardium)?; Forms a protective outer covering; secretes serous fluid. What type of tissue makes up the myocardium?; Cardiac muscle tissue separated by connective tissue and including blood capillaries, lymph capillaries, and nerve fibers. What is the primary function of the myocardium?; Contracts to pump blood from the heart chambers. What is the composition of the endocardium?; Membrane of epithelium and underlying connective tissue, including blood vessels. What is the function of the endocardium?; Forms a protective inner lining of the chambers and valves. How many chambers does the heart have?; 4 chambers (2 atria and 2 ventricles). What are the characteristics of the atria?; Thin-walled upper chambers; receive blood returning to the heart. What are auricles and their function?; Flap-like projections from atria, which allow atrial expansion. What are the characteristics of the ventricles?; Thick-walled lower chambers; pump blood into arteries. What is the function of the right atrium?; Receives blood returning from the systemic circuit (from the superior and inferior vena cavae and coronary sinus); pumps blood to the right ventricle. What is the function of the right ventricle?; Receives blood from the right atrium; pumps blood to the lungs. What is the function of the left atrium?; Receives blood from the pulmonary veins; pumps blood to the left ventricle. What is the function of the left ventricle?; Receives blood from the left atrium; pumps blood to the systemic circuit. Where is the tricuspid valve located?; Right atrioventricular orifice. What is the function of the tricuspid valve?; Prevents blood from moving from the right ventricle into the right atrium during ventricular contraction. Where is the pulmonary valve located?; Entrance to pulmonary trunk. What is the function of the pulmonary valve?; Prevents blood from moving from the pulmonary trunk into the right ventricle during ventricular relaxation. Where is the mitral valve located?; Left atrioventricular orifice. What is the function of the mitral valve?; Prevents blood from moving from the left ventricle into the left atrium during ventricular contraction. Where is the aortic valve located?; Entrance to aorta. What is the function of the aortic valve?; Prevents blood from moving from the aorta into the left ventricle during ventricular relaxation. What is the function of the superior vena cava?; It carries deoxygenated blood from the upper body to the right atrium of the heart. What is the role of the aorta in the cardiovascular system?; It carries oxygenated blood from the left ventricle to the rest of the body. Where does the right pulmonary artery transport blood?; It transports deoxygenated blood from the right ventricle to the lungs. What is the function of the left pulmonary veins?; They carry oxygenated blood from the lungs to the left atrium. What is the purpose of the tricuspid valve?; It prevents backflow of blood from the right ventricle to the right atrium. What is the role of the mitral (bicuspid) valve?; It prevents backflow of blood from the left ventricle to the left atrium. What is the function of the pulmonary valve?; It prevents backflow of blood from the pulmonary artery into the right ventricle. What is the interventricular septum?; It is the wall that separates the left and right ventricles of the heart. What is the function of the papillary muscles?; They contract to prevent inversion or prolapse of the atrioventricular valves during ventricular contraction. What is the role of the chordae tendineae?; They anchor the atrioventricular valves to the papillary muscles and prevent valve inversion. What is the function of the left ventricle?; It pumps oxygenated blood into the aorta for distribution to the body. What is the function of the right ventricle?; It pumps deoxygenated blood into the pulmonary artery for oxygenation in the lungs. What is the role of the inferior vena cava?; It carries deoxygenated blood from the lower body to the right atrium of the heart. What is the function of the tricuspid valve?; The tricuspid valve prevents backflow of blood from the right ventricle to the right atrium. Where is the mitral (bicuspid) valve located?; The mitral (bicuspid) valve is located between the left atrium and the left ventricle. What is the role of the aortic valve?; The aortic valve prevents backflow of blood from the aorta into the left ventricle. What is the function of the pulmonary valve?; The pulmonary valve prevents backflow of blood from the pulmonary artery into the right ventricle. What structures are labeled in the photo of the human tricuspid valve?; Right atrium, cusps of tricuspid valve, chordae tendineae, interventricular septum, papillary muscles, muscular ridges. What structures surround the origins of the pulmonary trunk and aorta, and orifices between atria and ventricles?; Rings of dense connective tissue. What is the function of the rings of dense connective tissue in the heart?; They provide attachments for heart valves and muscle fibers and prevent excess dilation of heart chambers during contraction. What prevents excess dilation of heart chambers during contraction?; Rings of dense connective tissue. What makes up the skeleton of the heart?; Rings of dense connective tissue and other fibrous masses in the interventricular septum. Where are the fibrous masses that contribute to the skeleton of the heart located?; In the interventricular septum. What is the first step in the blood flow through the heart?; Blood from the systemic circuit enters the right atrium. Which valve does blood pass through after the right atrium?; Tricuspid valve. Where does blood go after the right ventricle?; Pulmonary trunk. What is the function of the pulmonary arteries?; To carry blood from the heart to the lungs. Where does blood go after passing through the pulmonary capillaries in the lungs?; Pulmonary veins. Which chamber of the heart receives blood from the pulmonary veins?; Left atrium. Through which valve does blood pass after the left atrium?; Mitral (bicuspid) valve. Where does blood go after the left ventricle?; Aorta. What is the final step in the blood flow through the heart?; Blood is distributed to the systemic circuit. What is the role of the aortic valve?; To prevent backflow of blood from the aorta into the left ventricle. What is the function of the superior vena cava?; To carry deoxygenated blood from the upper body to the right atrium. What is the function of the inferior vena cava?; To carry deoxygenated blood from the lower body to the right atrium. What is the role of alveolar capillaries in the lungs?; To facilitate gas exchange between the blood and the air in the lungs. Which arteries supply blood to the tissues of the heart?; The left and right coronary arteries. What are the first two branches of the aorta?; The coronary arteries. Where do the coronary arteries originate from?; The aorta. What are the two main arteries that supply blood to the heart?; Right coronary artery and left coronary artery. Which artery branches off the right coronary artery to supply the ventricular walls?; Posterior interventricular artery. Which artery branches off the right coronary artery to supply the walls of the right atrium and right ventricle?; Marginal artery. Which artery branches off the left coronary artery to supply the walls of the left atrium and left ventricle?; Circumflex artery. Which artery branches off the left coronary artery to supply the ventricular walls?; Anterior interventricular artery. Where do the myocardial capillaries in the ventricular walls drain into?; Cardiac veins. Where do the cardiac veins drain into?; Coronary sinus. Where does the coronary sinus drain into?; Right atrium. What is the function of the aorta?; The aorta is the main artery that carries blood from the heart to the rest of the body. Where does the superior vena cava transport blood?; The superior vena cava transports deoxygenated blood from the upper body to the right atrium of the heart. What is the role of the right pulmonary artery?; The right pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. What is the function of the left pulmonary veins?; The left pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. What is the pulmonary trunk?; The pulmonary trunk is a major vessel that originates from the right ventricle and splits into the left and right pulmonary arteries. What is the left auricle?; The left auricle is a small, ear-shaped pouch that projects from the left atrium. What is the function of the left coronary artery?; The left coronary artery supplies blood to the left side of the heart muscle. What is the great cardiac vein?; The great cardiac vein collects deoxygenated blood from the heart muscle and returns it to the right atrium. What is the anterior interventricular artery?; The anterior interventricular artery, also known as the left anterior descending artery, supplies blood to the front of the left side of the heart. What is the function of the right atrium?; The right atrium receives deoxygenated blood from the body through the superior and inferior vena cava. What is the role of the right ventricle?; The right ventricle pumps deoxygenated blood to the lungs through the pulmonary arteries. What is the coronary sinus?; The coronary sinus is a large vein that collects blood from the heart muscle and empties into the right atrium. What is the function of the left ventricle?; The left ventricle pumps oxygenated blood to the rest of the body through the aorta. What is the apex of the heart?; The apex of the heart is the pointed end of the heart that is directed downward, forward, and to the left. What is the function of the right coronary artery?; The right coronary artery supplies blood to the right side of the heart muscle. What is the role of the inferior vena cava?; The inferior vena cava transports deoxygenated blood from the lower body to the right atrium of the heart. What is the posterior interventricular artery?; The posterior interventricular artery supplies blood to the posterior part of the heart. What is the cardiac cycle?; The events of a heartbeat. How do the heart chambers function during the cardiac cycle?; In a coordinated manner. What happens during atrial systole?; The atria contract while the ventricles relax (ventricular diastole). What happens during ventricular systole?; The ventricles contract while the atria relax (atrial diastole). What is atrial diastole?; The relaxation of the atria. What is ventricular diastole?; The relaxation of the ventricles. What is a heart transplant?; Replacement of most of a failing heart with a donor heart. What is a Left Ventricular Assist Device (LVAD)?; A mechanical half-heart, used in some cases temporarily, until a donor heart is available. What is an implantable replacement heart made of?; Titanium and plastic. Who typically receives an implantable replacement heart?; People who cannot have a heart transplant and do not have long to live. What does stem cell technology allow in terms of cardiac muscle tissue?; Cardiac muscle tissue can now be cultured from altered somatic cells or from stem cells. What future application might stem cell technology enable for heart treatment?; Stem cell heart patches. What happens to the pressure in the heart chambers during a cardiac cycle?; The pressure in the heart chambers rises and falls. What causes the heart valves to open and close during the cardiac cycle?; Pressure changes in the heart chambers. What happens to the ventricles during atrial systole and ventricular diastole?; The ventricles are relaxed. Which valves are open and which are closed during atrial systole and ventricular diastole?; The A-V valves are open and the semilunar valves are closed. What percentage of blood flows passively from the atria into the ventricles during atrial systole and ventricular diastole?; About 70% of blood. What happens to the remaining 30% of blood during atrial systole?; Atrial systole pushes the remaining 30% of blood into the ventricles, causing ventricular pressure to increase. What happens to the A-V valves during ventricular systole and atrial diastole?; The A-V valves close. What prevents the cusps of the valves from bulging too far backward into the atria during ventricular systole?; The chordae tendineae. What happens to the atria during ventricular systole and atrial diastole?; The atria relax. Where does blood flow into the atria from during ventricular systole and atrial diastole?; From the venae cavae and pulmonary veins. What happens to the ventricular pressure during ventricular systole?; The ventricular pressure increases and opens the semilunar valves. Where does blood flow during ventricular systole?; Blood flows into the pulmonary trunk and aorta. What does a heartbeat through a stethoscope sound like?; Lubb-dupp What causes the sounds heard in a heartbeat?; Closing of heart valves and vibrations associated with a sudden slowing of blood flow during contraction/relaxation of chambers What is the first heart sound called?; Lubb When does the 'lubb' sound occur?; During ventricular systole What is the 'lubb' sound associated with?; Closing of the A-V valves What is the second heart sound called?; Dupp When does the 'dupp' sound occur?; During ventricular diastole What is the 'dupp' sound associated with?; Closing of the pulmonary and aortic semilunar valves What is a murmur?; An abnormal heart sound derived from incomplete closure of cusps of a valve Where can the sounds of the aortic valve be heard?; In the aortic area, located at the second intercostal space to the right of the sternum. Where can the sounds of the pulmonary valve be heard?; In the pulmonary area, located at the second intercostal space to the left of the sternum. Where can the sounds of the tricuspid valve be heard?; In the tricuspid area, located at the fourth intercostal space to the left of the sternum. Where can the sounds of the mitral valve be heard?; In the mitral area, located at the fifth intercostal space at the midclavicular line. What type of networks do cardiac muscle cells form?; Branching networks. What do intercalated discs between cardiac muscle cells contain?; Gap junctions. What is the function of gap junctions in cardiac muscle cells?; They allow action potentials to spread through a network of cells. What is a functional syncytium in cardiac muscle fibers?; A mass of merging cells that function as a unit. How many functional syncytia exist in the heart?; Two. Where is the atrial syncytium located?; In the atrial walls. Where is the ventricular syncytium located?; In the ventricular walls. What is the cardiac conduction system?; A group of clumps and strands of specialized cardiac muscle tissue, which initiates and distributes impulses throughout the myocardium. What is the function of the cardiac conduction system?; It coordinates the events of the cardiac cycle. What is the first component of the cardiac conduction system?; SA node. What follows the SA node in the cardiac conduction system?; Atrial syncytium. What follows the atrial syncytium in the cardiac conduction system?; Junctional fibers. What follows the junctional fibers in the cardiac conduction system?; AV node. What follows the AV node in the cardiac conduction system?; AV bundle. What follows the AV bundle in the cardiac conduction system?; Bundle branches. What follows the bundle branches in the cardiac conduction system?; Purkinje fibers. What follows the Purkinje fibers in the cardiac conduction system?; Ventricular syncytium. What is the role of the SA (Sinoatrial) Node in the cardiac conduction system?; It acts as the pacemaker and initiates rhythmic contractions of the heart. What is the function of the Internodal Atrial Muscle?; It conducts impulses from the SA node to the atria. What do Junctional Fibers do in the cardiac conduction system?; They conduct impulses from the SA node to the AV node. What is the role of the AV (Atrioventricular) Node?; It conducts impulses to the AV Bundle and delays the impulse so that the atria finish contracting before the ventricles contract. What is the function of the AV (Atrioventricular) Bundle (of His)?; It conducts impulses rapidly between the SA node and the bundle branches. What is the role of the Left and Right Bundle Branches?; They split off from the AV bundle and conduct impulses to the Purkinje fibers on both sides of the heart. What do Purkinje Fibers do in the cardiac conduction system?; They are large fibers that conduct impulses to the ventricular myocardium. What are the major components of the cardiac conduction system?; SA node, AV node, AV bundle, right bundle branch, left bundle branch, Purkinje fibers. What happens when Purkinje fibers stimulate muscle cells in the ventricles?; The ventricles contract with a twisting motion. Where are the whorled networks of muscle located in the heart?; In the walls of the ventricles. What is the function of the SA node in the cardiac conduction system?; It acts as the natural pacemaker of the heart, initiating the heartbeat. What role does the AV node play in the cardiac conduction system?; It delays the electrical impulse before it passes to the ventricles, ensuring the atria contract before the ventricles. What is the function of the AV bundle in the cardiac conduction system?; It transmits the electrical impulses from the AV node to the bundle branches. What is the role of the right and left bundle branches in the cardiac conduction system?; They conduct impulses through the interventricular septum to the Purkinje fibers. What is the significance of the twisting motion of the ventricles during contraction?; It helps to efficiently pump blood out of the ventricles. What does an electrocardiogram (ECG or EKG) record?; Electrical changes that occur in the myocardium during the cardiac cycle. What is the primary use of an electrocardiogram?; To assess the heart’s ability to conduct impulses. What does the P wave in an ECG represent?; Atrial depolarization; occurs just prior to atrial contraction. What does the QRS complex in an ECG represent?; Ventricular depolarization; occurs just prior to ventricular contraction. What does the T wave in an ECG represent?; Ventricular repolarization; occurs just prior to ventricular relaxation. Why is the record of atrial repolarization not visible in an ECG?; It is 'hidden' in the large QRS complex, since ventricular depolarization is a much larger event. What does Figure 15.19 illustrate?; The relationship between the ECG and the phases of the cardiac cycle. What is represented by the P wave in an ECG?; Atrial depolarization. What occurs during the QRS complex in an ECG?; Ventricular depolarization. What does the T wave in an ECG represent?; Ventricular repolarization. What phase of the cardiac cycle is associated with the P wave?; Atrial systole. During which phase of the cardiac cycle does the QRS complex occur?; Ventricular systole. What phase of the cardiac cycle is associated with the T wave?; Ventricular diastole. What happens to the atria during the QRS complex?; Atrial repolarization. What is the significance of the PR interval in an ECG?; It represents the time between the onset of atrial depolarization and the onset of ventricular depolarization. What does the ST segment in an ECG indicate?; The period when the ventricles are depolarized. What does the first graph in Figure 15.20 represent?; Pressure changes in the aorta, ventricles, and atria during the cardiac cycle. What does the second graph in Figure 15.20 show?; Ventricular volume changes during the cardiac cycle. What does the third graph in Figure 15.20 depict?; Electrocardiogram (ECG) readings during the cardiac cycle. What does the fourth graph in Figure 15.20 illustrate?; Heart sounds during the cardiac cycle. What event is indicated by the opening of the AV valve in Figure 15.20?; The beginning of ventricular filling. What does the closing of the AV valve signify in Figure 15.20?; The end of ventricular filling and the beginning of ventricular systole. What does the opening of the aortic valve indicate in Figure 15.20?; The beginning of ventricular ejection. What does the closing of the aortic valve signify in Figure 15.20?; The end of ventricular ejection and the beginning of ventricular diastole. What is the significance of the P wave in the ECG graph of Figure 15.20?; Atrial depolarization. What does the QRS complex represent in the ECG graph of Figure 15.20?; Ventricular depolarization. What does the T wave indicate in the ECG graph of Figure 15.20?; Ventricular repolarization. What causes the first heart sound (S1) in Figure 15.20?; The closing of the AV valves. What causes the second heart sound (S2) in Figure 15.20?; The closing of the aortic and pulmonary valves. What node normally controls the heart rate?; The SA node. Which fibers modify the heart rate in response to changing conditions?; Sympathetic and parasympathetic fibers. Name some conditions that can modify the heart rate.; Physical exercise, body temperature, fight-or-flight, and concentration of various ions such as K+ and Ca+2. How do parasympathetic impulses affect the heart rate?; Parasympathetic impulses via vagus nerves decrease heart rate due to influence on SA and AV nodes. How do sympathetic impulses affect the heart rate?; Sympathetic impulses via accelerator nerves increase heart rate due to influence on SA and AV nodes, and ventricular myocardium. Where do baroreceptor reflexes arise from?; From the cardiac control center in the medulla oblongata. What is the function of baroreceptor reflexes?; To balance inhibitory and excitatory effects of parasympathetic and sympathetic fibers. What does the cardiac control center regulate?; It regulates autonomic impulses to the heart. What is the function of baroreceptors in the cardiovascular system?; Baroreceptors detect changes in blood pressure and send signals to the central nervous system. Where are the baroreceptors located in the cardiovascular system?; Baroreceptors are located in the carotid sinuses and the aortic arch. What is the role of the central nervous system in the baroreceptor reflex?; The central nervous system processes signals from baroreceptors and sends autonomic impulses to alter heart action. What type of neurons carry signals from baroreceptors to the central nervous system?; Sensory or afferent neurons. What type of neurons carry signals from the central nervous system to the heart in the baroreceptor reflex?; Motor or efferent neurons. How do autonomic impulses affect the heart in the baroreceptor reflex?; Autonomic impulses alter heart action to regulate blood pressure. What is the general pathway of the baroreceptor reflex?; Receptor (baroreceptors) → Sensory neuron → Central nervous system → Motor neuron → Effector (heart). What is the effector in the baroreceptor reflex arc?; The heart. What are arrhythmias?; Altered heart rhythms. What is fibrillation?; Uncoordinated, chaotic contraction of small areas of myocardium. Is atrial fibrillation life-threatening?; No, atrial fibrillation is not life-threatening. Is ventricular fibrillation life-threatening?; Yes, ventricular fibrillation is often fatal. What is tachycardia?; Abnormally fast heartbeat, >100 beats/min at rest. What is bradycardia?; Abnormally slow heartbeat, <60 beats/min at rest. What is flutter?; Rapid, regular contraction of a heart chamber, 250-350 beats/min. What is a premature beat?; A beat that occurs before expected in the normal cardiac cycle, often originating from ectopic regions of the heart (other than SA node). What is an ectopic pacemaker?; When damage to the SA node leads to the AV node taking over and acting as a secondary pacemaker, with a rate of 40-60 beats/min instead of 70-80. What is an artificial pacemaker?; A device used to treat disorders of the cardiac conduction system; it is implantable and battery-powered. What are blood vessels?; Organs of the cardiovascular system. What is the function of blood vessels?; To form a closed circuit, transporting blood from the heart to body cells (or lungs) and back to the heart. What do arteries do?; Carry blood away from the ventricles of the heart. What is the function of arterioles?; Receive blood from the arteries and carry it to the capillaries. What is the role of capillaries?; Sites of exchange of substances between the blood and the body cells. What do venules do?; Receive blood from the capillaries and conduct it to veins. What is the function of veins?; Receive blood from venules and carry it back to the atria of the heart. What are the two types of blood vessels shown in Figure 15.23?; Arteriole (bottom) and Venule (top). What is the function of the endothelium in blood vessels?; The endothelium lines the interior surface of blood vessels, providing a smooth surface for blood flow. What type of tissue is found in the tunica media of blood vessels?; The tunica media contains smooth muscle tissue. What is the role of valves in veins?; Valves in veins prevent the backflow of blood, ensuring it flows in one direction towards the heart. What is the outermost layer of a blood vessel called?; The outermost layer is called the tunica externa. What is the lumen in a blood vessel?; The lumen is the central cavity through which blood flows. What type of connective tissue is found in the tunica media?; The tunica media contains elastic and collagen fibers. What is the primary difference between arterioles and venules?; Arterioles carry blood away from the heart and have thicker walls with more smooth muscle, while venules carry blood towards the heart and have thinner walls with less smooth muscle. What is angiogenesis?; Formation of new blood vessels. What mainly controls angiogenesis?; Vascular Endothelial Growth Factor (VEGF). Why is angiogenesis regulated in the body?; Because excess, deficient, or inappropriate blood vessel formation can cause common diseases. How does the body promote angiogenesis in response to a blocked coronary artery?; The body secretes VEGF. What can be done if the body's secretion of VEGF is not sufficient to promote angiogenesis?; VEGF may be delivered in time-release capsules. Why do tumors secrete VEGF?; To nourish themselves. What are antiangiogenesis drugs used to treat?; Cancer and age-related macular degeneration. What are the characteristics of artery walls?; Thick, strong walls, thicker than the walls of veins. What are the three layers or tunics of arteries?; Tunica interna (intima), Tunica media, Tunica externa (adventitia). What is the innermost layer of an artery called?; Tunica interna (intima). What is the composition of the tunica media in arteries?; Smooth muscle and elastic tissue. What is the outer layer of an artery called?; Tunica externa (adventitia). What type of tissue makes up the tunica externa (adventitia)?; Connective tissue. Under what condition do arteries transport blood?; Under high blood pressure. What do arteries give rise to?; Smaller arterioles. How do the walls of arterioles compare to those of arteries?; Arterioles have thinner walls than arteries but have the same three layers or tunics. What happens to the walls of arterioles as they become smaller?; The walls of the middle and outer layers become thinner as arterioles become smaller. What functions can both arteries and arterioles perform?; Both arteries and arterioles can undergo vasoconstriction and vasodilation. What is an arteriole?; A small blood vessel that branches out from an artery and leads to capillaries. What type of cells are found in the walls of arterioles?; Smooth muscle cells. What is the function of the precapillary sphincter?; It regulates blood flow into capillaries. What is the role of endothelium in arterioles?; It lines the interior surface of the blood vessels. How many muscle fibers do small arterioles contain in their walls?; Only a few muscle fibers. What are the smallest-diameter blood vessels?; Capillaries. What do capillaries connect?; The smallest arterioles and the smallest venules. What are capillaries extensions of?; The inner lining of arterioles. What do the walls of capillaries consist of?; Endothelium (simple squamous epithelium) only. Are capillaries permeable?; They are semi-permeable. What mainly regulates capillary blood flow?; Precapillary sphincters. What are precapillary sphincters?; Smooth muscle surrounding capillary when it branches off arteriole or metarteriole. How are substances exchanged in capillaries?; By diffusion. What are the openings in the walls of capillaries called?; Thin slits found where endothelial cells overlap. How does the size of openings in capillaries vary?; The sizes of openings vary among tissues. What determines the permeability of capillaries?; The size of the slits. What determines the density of capillary networks in a tissue?; The metabolic rate of the tissue. Which tissues have a rich capillary supply?; Muscle and nerve tissues. Why do muscle and nerve tissues have a rich capillary supply?; Because they use a large amount of O2 and nutrients. Which tissues have fewer capillaries?; Tissues with lower metabolic rates, such as cartilage. What is the primary function of capillaries?; To exchange gases, nutrients, and metabolic byproducts between blood and tissue around cells. What is the most important method of transfer in capillary exchange?; Diffusion. How do lipid-soluble substances diffuse in capillaries?; Through the cell membrane. How do water-soluble substances diffuse in capillaries?; Through membrane channels and slits. What forces molecules through the membrane during filtration in capillaries?; Hydrostatic pressure. Where does the pressure for filtration in capillaries come from?; From ventricular contraction. What creates osmotic pressure in capillaries?; The presence of impermeant solutes, such as plasma proteins, inside capillaries. What is the role of osmotic pressure in capillary exchange?; It draws water into capillaries, opposing filtration. What happens at the arteriolar end of a capillary during capillary exchange?; H2O and other substances leave the capillary because hydrostatic pressure is greater than osmotic pressure. What causes H2O and other substances to leave the capillary at the arteriolar end?; Hydrostatic pressure being greater than osmotic pressure. What happens at the venular end of a capillary during capillary exchange?; H2O enters the capillary because osmotic pressure is greater than hydrostatic pressure. What causes H2O to enter the capillary at the venular end?; Osmotic pressure being greater than hydrostatic pressure. What is the net outward force at the arteriolar end of a capillary?; 11 mm Hg (35 mm Hg outward force of hydrostatic pressure - 24 mm Hg inward force of osmotic pressure). What is the net inward force at the venular end of a capillary?; 8 mm Hg (24 mm Hg inward force of osmotic pressure - 16 mm Hg outward force of hydrostatic pressure). What are venules?; Microscopic vessels that transport blood from the capillaries to veins. How do the walls of venules compare to those of arterioles?; Venules have thinner walls and less smooth muscle than arterioles. How do the walls of veins compare to those of arteries?; Veins have thinner walls than arteries. How many layers or tunics do veins have?; Three layers or tunics. How is the tunica media of veins different from that of arteries?; The tunica media is less developed in veins. Under what pressure do veins carry blood?; Veins carry blood under relatively low pressure. What function do veins serve in addition to carrying blood?; Veins function as blood reservoirs. What special feature do many veins have?; Many veins have flap-like valves. What percentage of blood is in veins and venules at any time?; About 2/3 of blood. What is the percentage distribution of blood in systemic veins?; 60-70% What is the percentage distribution of blood in the lungs?; 10-12% What is the percentage distribution of blood in the heart?; 8-11% What is the percentage distribution of blood in systemic arteries?; 10-12% What is the percentage distribution of blood in capillaries?; 4-5% What are the three layers of an artery wall?; An endothelial lining, a middle layer of smooth muscle and elastic connective tissue, and an outer layer of connective tissue. What is the function of an artery?; Carries blood under relatively high pressure from the heart to arterioles. How does the wall of an arteriole compare to that of an artery?; An arteriole has a thinner wall than an artery but still has three layers; smaller arterioles have an endothelial lining, some smooth muscle tissue, and a small amount of connective tissue. What is the function of an arteriole?; Connects an artery to a capillary, helps control the blood flow into a capillary by vasoconstricting or vasodilating. What is the structure of a capillary wall?; A single layer of squamous epithelium. What is the function of a capillary?; Allows nutrients, gases, and wastes to be exchanged between the blood and tissue fluid. How does the wall of a venule compare to that of an arteriole?; A venule has a thinner wall than an arteriole, with less smooth muscle and elastic connective tissue. What is the function of a venule?; Connects a capillary to a vein. How does the wall of a vein compare to that of an artery?; A vein has a thinner wall than an artery but with similar layers; the middle layer is more poorly developed, and some veins have flap-like valves. What is the function of a vein?; Carries blood under relatively low pressure from a venule to the heart; valves prevent a backflow of blood; serves as a blood reservoir. What is atherosclerosis?; Deposits of cholesterol plaque form in the inner lining of walls of arteries. What is an aneurysm?; A bulge in the wall of an artery, formed when blood pressure dilates a weakened area of the vessel; can burst the wall of the artery. What is phlebitis?; Inflammation of a vein; common disorder. What are varicose veins?; Abnormal and irregular dilations in superficial veins; most common in legs. What is blood pressure?; The force the blood exerts against the inner walls of the blood vessels. What role does blood pressure play in the circulatory system?; Blood pressure circulates the blood. To which blood vessels does the term 'blood pressure' most commonly refer?; Systemic arteries. Is there blood pressure throughout the entire vascular system?; Yes, there is blood pressure throughout the vascular system. How does blood move through the vascular system?; Blood moves from higher to lower pressure throughout the system. When does arterial blood pressure rise?; When the ventricles contract. When does arterial blood pressure fall?; When the ventricles relax. What is systolic pressure (SP)?; The maximum pressure reached during ventricular contraction. What is diastolic pressure (DP)?; The minimum pressure remaining before the next ventricular contraction. What is pulse pressure (PP)?; The difference between systolic and diastolic blood pressures (SP - DP). What is mean arterial pressure (MAP)?; The average pressure in the arterial system; represents the average force driving blood to the tissues. How is mean arterial pressure (MAP) calculated?; MAP = DP + 1/3 PP. How is blood pressure typically stated?; As a fraction: SP/DP, as in 120/80. In what units is blood pressure measured?; mm Hg. What is typically used to measure arterial blood pressure?; A sphygmomanometer. What are the main components of a sphygmomanometer?; Air control valve, bulb, pressure gauge, inflatable cuff. What is the function of the inflatable cuff in a sphygmomanometer?; To apply pressure to the arm to measure blood pressure. What does the pressure gauge in a sphygmomanometer measure?; The arterial blood pressure. How is air controlled in a sphygmomanometer?; Using the air control valve. What is the purpose of the bulb in a sphygmomanometer?; To inflate the cuff by pumping air into it. What happens to blood pressure as the distance from the left ventricle increases?; Blood pressure decreases. What is the trend of systolic and diastolic pressure as blood moves away from the left ventricle?; Both systolic and diastolic pressures decrease. In which part of the circulatory system is the blood pressure the highest?; In the aorta. Where does the most significant drop in blood pressure occur in the circulatory system?; In the arterioles. What is the blood pressure trend in capillaries compared to arterioles?; Blood pressure continues to decrease in capillaries. How does blood pressure in veins compare to that in arteries?; Blood pressure in veins is much lower than in arteries. What is the blood pressure in the vena cava compared to the aorta?; Blood pressure in the vena cava is significantly lower than in the aorta. What are the sites for measuring the arterial pulse as shown in Figure 15.33?; Temporal artery, Carotid artery, Facial artery, Brachial artery, Radial artery, Femoral artery, Popliteal artery, Posterior tibial artery, Dorsalis pedis artery. Where is the temporal artery located for measuring the pulse?; On the side of the head near the temple. Where is the carotid artery located for measuring the pulse?; In the neck. Where is the facial artery located for measuring the pulse?; On the face, near the jawline. Where is the brachial artery located for measuring the pulse?; On the inner side of the upper arm. Where is the radial artery located for measuring the pulse?; On the wrist, near the thumb. Where is the femoral artery located for measuring the pulse?; In the groin area. Where is the popliteal artery located for measuring the pulse?; Behind the knee. Where is the posterior tibial artery located for measuring the pulse?; Near the ankle. Where is the dorsalis pedis artery located for measuring the pulse?; On the top of the foot. What happens to blood pressure when blood volume increases?; Blood pressure increases. How does an increase in heart rate affect blood pressure?; It increases blood pressure. What is the effect of increased stroke volume on blood pressure?; It increases blood pressure. What happens to blood pressure when blood viscosity increases?; Blood pressure increases. How does an increase in peripheral resistance affect blood pressure?; It increases blood pressure. What is stroke volume (SV)?; The volume of blood that enters the arteries with each ventricular contraction (~70 mL/beat). What is cardiac output (CO)?; The volume of blood discharged from a ventricle each minute. How is cardiac output (CO) calculated?; Cardiac output = Stroke volume × Heart rate (CO = SV × HR). What is the formula for cardiac output if stroke volume is 70 mL/beat and heart rate is 72 beats/min?; CO = 70 mL/beat × 72 beats/min = 5,040 mL/min. How does blood pressure vary with cardiac output?; Blood pressure varies directly with cardiac output. What happens to blood pressure if stroke volume (SV) or heart rate (HR) increases?; An increase in SV or HR causes an increase in CO, which increases blood pressure (BP). What constitutes blood volume?; The sum of volumes of plasma and formed elements. What factors cause blood volume to vary?; Age, body size, and gender. What is the average blood volume for adults?; About 5 liters (4 to 5 liters in a female and 5 to 6 liters in a male). What percentage of body weight does blood volume constitute?; 8% of body weight. How is blood pressure (BP) related to blood volume?; Blood pressure is directly proportional to blood volume. What can change blood pressure?; Any factor that changes blood volume. What happens to blood pressure when blood volume decreases due to hemorrhage?; Blood pressure decreases. What is Peripheral Resistance (PR)?; The force of friction between blood and the walls of blood vessels. What must blood pressure overcome in order to flow?; Peripheral Resistance (PR). How do factors that change Peripheral Resistance (PR) affect blood pressure?; Factors that change PR also change blood pressure. What effect does vasoconstriction of arterioles have on Peripheral Resistance (PR) and blood pressure?; Vasoconstriction of arterioles increases PR, which increases blood pressure. What happens to arteries when blood is pumped out of the ventricles?; Arteries swell and rapid elastic recoil sends the blood through the arteries, against PR in arterioles and capillaries. What is viscosity?; The difficulty with which molecules of fluid flow past each other. How does greater viscosity affect blood flow?; Greater viscosity increases the resistance to blood flow. What components increase the viscosity of blood?; Blood cells and plasma proteins. How does increased resistance to blood flow affect blood pressure?; Greater resistance to flow requires greater force to transport the blood, which increases blood pressure. What happens to blood viscosity and blood pressure when the concentration of blood cells or plasma proteins is altered?; Any factor that alters the concentration of blood cells or plasma proteins also alters blood viscosity, which in turn affects blood pressure. How does anemia affect blood viscosity and blood pressure?; Anemia lowers the concentration of blood cells, which lowers blood viscosity and subsequently lowers blood pressure. What determines blood pressure (BP)?; Cardiac output (CO) and peripheral resistance (PR). What is the formula for blood pressure?; BP = CO × PR What two factors need to be regulated to maintain blood pressure?; Cardiac output (CO) and peripheral resistance (PR). What happens to cardiac output when blood pressure increases?; Cardiac output increases. What stimulates baroreceptors in the aortic arch and carotid sinuses?; An increase in blood pressure. Where do sensory impulses go after baroreceptors are stimulated?; To the cardiac center. What type of impulses are sent to the heart to decrease heart rate?; Parasympathetic impulses. What effect does the inhibition of the SA node have on heart rate?; It decreases heart rate. What is the final result of the process that starts with increased cardiac output?; Blood pressure returns toward normal. What happens to the vasomotor center when blood pressure rises?; It is inhibited. What is the effect of less frequent sympathetic impulses to arteriole walls?; Vasodilation of arterioles. What happens to peripheral resistance when arterioles vasodilate?; Peripheral resistance decreases. What is the final result of the process that starts with rising blood pressure?; Blood pressure returns toward normal. What is hypertension?; Long-lasting elevated arterial blood pressure. What are some causes of hypertension?; Unknown cause, increased Na+ intake, psychological stress, obesity, kidney disease. Why is hypertension often called the 'silent killer'?; Because it may not cause any direct symptoms. How does hypertension contribute to cardiovascular diseases?; It contributes to the formation of atherosclerosis. What are some potential complications of hypertension?; Coronary thrombosis, embolism, cerebral thrombosis, embolism, hemorrhage, transient ischemic attack (TIA), cerebral vascular accident (CVA). What are some preventive measures for hypertension?; Healthy diet and weight, regular exercise, limiting Na+ intake. What are some treatments for hypertension?; Diuretics, sympathetic inhibitors. How does obesity contribute to hypertension?; By increasing peripheral resistance. How can kidney disease lead to hypertension?; Via the renin-angiotensin response. What happens to blood pressure as blood moves through the arterial system and into the capillary network?; Blood pressure decreases. Why is there little pressure remaining at the venous ends of the capillaries?; Because blood pressure decreases as blood moves through the arterial system and into the capillary network. Is venous blood flow solely a direct result of heart action?; No, it is only partly a direct result of heart action. What are the three factors that venous blood flow depends on?; Skeletal muscle contraction, breathing movements, and vasoconstriction of veins. How does skeletal muscle contraction affect venous blood flow?; Skeletal muscle contraction helps to push blood through the veins. How do breathing movements influence venous blood flow?; Breathing movements create pressure changes that help to move blood through the veins. What role does vasoconstriction of veins play in venous blood flow?; Vasoconstriction of veins helps to increase the pressure within the veins, aiding blood flow back to the heart. Where do all veins, except those returning to the heart from the lungs, drain into?; The right atrium. What is the pressure in the right atrium called?; Central venous pressure. What factors influence central venous pressure?; Factors that alter the flow of blood into the right atrium. How does central venous pressure affect peripheral veins?; It affects the pressure within the peripheral veins. What effect does a weakly beating heart have on central venous pressure?; It increases central venous pressure. What happens when there is an increase in central venous pressure?; Blood backs up into the peripheral veins. What can result from blood backing up into the peripheral veins?; Peripheral edema. What increases blood flow to the right atrium, thereby increasing central venous pressure?; An increase in blood volume or venoconstriction. What are the benefits of regular aerobic exercise on the cardiovascular system?; Increased pumping efficiency, blood volume, hemoglobin concentration, number of mitochondria, heart enlargement, increased stroke volume, decreased heart rate and blood pressure. By how much can the heart enlarge due to regular aerobic exercise?; 40% or more. What happens to stroke volume as a result of regular aerobic exercise?; Stroke volume increases. How does regular aerobic exercise affect heart rate and blood pressure?; Heart rate and blood pressure decrease. What percentage of maximum heart rate should be achieved for exercise to benefit the cardiovascular system?; 70 to 85% of maximum (220 - your age). How long should each exercise session last to benefit the cardiovascular system?; 30 to 60 minutes. How often should one exercise per week to benefit the cardiovascular system?; At least 3 to 4 times per week. What are the two pathways formed by blood vessels?; The pulmonary circuit and the systemic circuit. What is the function of the pulmonary circuit?; The pulmonary circuit carries blood between the heart and the lungs. What is the function of the systemic circuit?; The systemic circuit carries blood between the heart and the rest of the body. Which circuit involves the exchange of gases in the lungs?; The pulmonary circuit. Which circuit supplies oxygenated blood to the body's tissues?; The systemic circuit. What is the pathway of blood in the pulmonary circuit?; Right ventricle → pulmonary trunk → right and left pulmonary arteries → lobar branches, repeated divisions → pulmonary arterioles → pulmonary capillaries → pulmonary venules and veins → left atrium. What is the oxygen and carbon dioxide content of blood in the pulmonary arteries and arterioles?; Blood in pulmonary arteries and arterioles is low in O2 and high in CO2. Where does gas exchange occur in the pulmonary circuit?; Gas exchange occurs in pulmonary (alveolar) capillaries. What is the oxygen and carbon dioxide content of blood in the pulmonary venules and veins?; Blood in pulmonary venules and veins is rich in O2 and low in CO2. What is the pathway of blood in the systemic circuit?; Left ventricle → aorta → all arteries and arterioles leading to body tissues → systemic capillaries → systemic venules and veins → right atrium. Where does oxygen-rich blood move from and to in the systemic circuit?; Oxygen-rich blood moves from left atrium to left ventricle. What happens when the left ventricle contracts in the systemic circuit?; Contraction of left ventricle sends blood into systemic circuit. What is the effect of high osmotic pressure in interstitial fluid on alveoli?; It draws water out of the alveoli. What contributes to the osmotic pressure of the interstitial fluid?; Solutes that fail to enter the alveoli. Where does fluid from the interstitial space enter?; Lymphatic capillary or alveolar (blood) capillary. What happens to any excess water in the alveoli?; It is drawn out by the higher osmotic pressure of the interstitial fluid. What is the role of the pulmonary capillary in the alveolar wall?; It allows slight net outflow of fluid. What is the largest artery in the body?; The aorta. What does the aorta supply blood to?; All of the systemic arteries. What are the branches of the ascending aorta?; Right and left coronary arteries. What organ is supplied by the right and left coronary arteries?; Heart. What are the branches of the arch of the aorta?; Brachiocephalic trunk, left common carotid artery, and left subclavian artery. Which regions are supplied by the brachiocephalic trunk?; Right upper limb and right side of the head. Which region is supplied by the left common carotid artery?; Left side of the head. Which region is supplied by the left subclavian artery?; Left upper limb. What are the branches of the abdominal aorta?; Celiac artery, superior mesenteric artery, suprarenal artery, renal artery, gonadal artery, inferior mesenteric artery, lumbar artery, middle sacral artery, and common iliac artery. Which organs are supplied by the celiac artery?; Organs of the upper digestive tract. Which region is supplied by the phrenic artery?; Diaphragm. Which organs are supplied by the superior mesenteric artery?; Portions of the small and large intestines. Which organ is supplied by the suprarenal artery?; Adrenal gland. Which organ is supplied by the renal artery?; Kidney. Which organs are supplied by the gonadal artery?; Ovary or testis. Which region is supplied by the inferior mesenteric artery?; Lower portions of the large intestine. Which region is supplied by the lumbar artery?; Posterior abdominal wall. Which regions are supplied by the middle sacral artery?; Sacrum and coccyx. Which regions are supplied by the common iliac artery?; Lower abdominal wall, pelvic organs, and lower limb. What are the branches of the thoracic aorta?; Bronchial artery, pericardial artery, esophageal artery, mediastinal artery, and posterior intercostal artery. Which region is supplied by the bronchial artery?; Bronchi. Which region is supplied by the pericardial artery?; Pericardium. Which region is supplied by the esophageal artery?; Esophagus. Which region is supplied by the mediastinal artery?; Mediastinum. Which region is supplied by the posterior intercostal artery?; Thoracic wall. What is the name of the vessel labeled as 'Right common carotid a.'?; Right common carotid artery. What is the name of the vessel labeled as 'Right internal jugular v.'?; Right internal jugular vein. What is the name of the vessel labeled as 'Right subclavian a.'?; Right subclavian artery. What is the name of the vessel labeled as 'Brachiocephalic trunk'?; Brachiocephalic trunk. What is the name of the vessel labeled as 'Right subclavian v.'?; Right subclavian vein. What is the name of the vessel labeled as 'Brachiocephalic v.'?; Brachiocephalic vein. What is the name of the vessel labeled as 'Superior vena cava'?; Superior vena cava. What is the name of the vessel labeled as 'Right pulmonary a.'?; Right pulmonary artery. What is the name of the vessel labeled as 'Right pulmonary vv.'?; Right pulmonary veins. What is the name of the structure labeled as 'Right auricle'?; Right auricle. What is the name of the vessel labeled as 'Left common carotid a.'?; Left common carotid artery. What is the name of the vessel labeled as 'Left internal jugular v.'?; Left internal jugular vein. What is the name of the vessel labeled as 'Left subclavian a.'?; Left subclavian artery. What is the name of the vessel labeled as 'Left subclavian v.'?; Left subclavian vein. What is the name of the structure labeled as 'Aortic arch'?; Aortic arch. What is the name of the structure labeled as 'Ligamentum arteriosum'?; Ligamentum arteriosum. What is the name of the vessel labeled as 'Left pulmonary a.'?; Left pulmonary artery. What is the name of the vessel labeled as 'Left pulmonary vv.'?; Left pulmonary veins. What is the name of the structure labeled as 'Left auricle'?; Left auricle. What is the name of the vessel labeled as 'Pulmonary trunk'?; Pulmonary trunk. What is the main artery shown in Figure 15.42?; The abdominal aorta. Which artery branches off to supply the liver?; The hepatic artery. Which artery supplies blood to the spleen?; The splenic artery. What are the major branches of the abdominal aorta shown in the figure?; Celiac artery, hepatic artery, splenic artery, renal artery, superior mesenteric artery, inferior mesenteric artery, and common iliac arteries. Which artery supplies blood to the kidneys?; The renal artery. Which arteries branch off from the superior mesenteric artery?; Intestinal branches. Which arteries branch off from the inferior mesenteric artery?; Branches to the lower part of the large intestine. Which arteries are located at the end of the abdominal aorta?; The common iliac arteries. Which arteries supply blood to the brain, head, and neck?; Branches of the subclavian and common carotid arteries. What is the function of the subclavian arteries?; To supply blood to the brain, head, and neck. What is the function of the common carotid arteries?; To supply blood to the brain, head, and neck. Which artery branches into the internal and external carotid arteries?; The common carotid artery. What does the internal carotid artery supply?; The brain. What does the external carotid artery supply?; The face and neck. Which artery is labeled as 'a' in the diagram?; The internal carotid artery. Which artery is labeled as 'b' in the diagram?; The external carotid artery. Which artery is labeled as 'c' in the diagram?; The vertebral artery. Which artery is labeled as 'd' in the diagram?; The subclavian artery. What is the cerebral arterial circle also known as?; The circle of Willis. Which artery systems does the cerebral arterial circle join?; The carotid and vertebral artery systems. What is the function of the cerebral arterial circle?; It supplies blood to the brain and provides alternate pathways for blood to reach the brain. From where do the cerebral arteries emerge to supply blood to brain tissues?; From the cerebral arterial circle (circle of Willis). What artery gives off branches in the neck and continues into the arm?; The subclavian artery. What is the name of the artery that continues from the subclavian artery into the arm?; The axillary artery. Which artery is located in the upper arm and is a continuation of the axillary artery?; The brachial artery. What are the two main branches of the brachial artery in the forearm?; The radial artery and the ulnar artery. Which artery supplies blood to the thumb?; The principal artery of the thumb. What is the name of the artery that supplies blood to the deep structures of the arm?; The deep brachial artery. Which arteries form the palmar arches in the hand?; The deep palmar arch and the superficial palmar arch. What are the names of the arteries that supply blood to the fingers?; The digital arteries. Which artery is responsible for the blood supply to the posterior humeral circumflex region?; The posterior humeral circumflex artery. Which artery is responsible for the blood supply to the anterior humeral circumflex region?; The anterior humeral circumflex artery. Which arteries supply blood to the thoracic wall?; Branches of the subclavian artery and the thoracic aorta. What is the role of the subclavian artery in the thoracic wall?; It supplies blood to the thoracic wall. What is the role of the thoracic aorta in the thoracic wall?; It supplies blood to the thoracic wall. Which arteries are labeled in the diagram of the thoracic and abdominal walls?; Posterior intercostal a., Internal intercostal m., Internal thoracic a., External intercostal m., Anterior intercostal aa. What structures are shown in the diagram of the thoracic and abdominal walls?; Vertebral body, Thoracic aorta, Sternum, Costal cartilage. Into which arteries does the abdominal aorta divide?; The common iliac arteries. What regions do the common iliac arteries supply blood to?; The pelvic organs, gluteal region, and lower limbs. Into which arteries does the common iliac artery divide?; The internal iliac artery and external iliac artery. Which artery supplies blood to the pelvic and gluteal areas?; The internal iliac artery. What arteries provide the major blood supply to the lower limbs?; The external iliac arteries. Where are the external iliac arteries located?; They are located in the lower abdomen and pelvis, extending into the lower limbs. What is the function of the external iliac arteries?; To provide the major blood supply to the lower limbs. What is the main function of the venous system?; To return deoxygenated blood back to the heart. What major vein returns blood from the upper body to the heart?; Superior vena cava. What major vein returns blood from the lower body to the heart?; Inferior vena cava. Which vein is responsible for draining blood from the brain?; Internal jugular vein. Which vein is responsible for draining blood from the arms?; Subclavian vein. What is the name of the vein that drains blood from the liver?; Hepatic vein. Which vein drains blood from the kidneys?; Renal vein. What is the name of the vein that drains blood from the legs?; Femoral vein. Which vein is located in the lower leg and drains blood from the foot?; Anterior tibial vein. What is the function of the external jugular vein?; To drain blood from the face and neck. What does systemic venous circulation do?; Returns blood to the heart after exchange of gases, nutrients, and wastes between blood and cells. How do vessels of the venous system originate?; From the merging of capillaries into venules, venules into small veins, and small veins into larger ones. Why are venous pathways difficult to follow compared to arterial pathways?; Due to irregular networks and unnamed tributaries. What do pathways of larger veins usually parallel?; Arteries of the same name. Into which veins do all systemic veins converge?; Superior and inferior venae cavae. Through which part of the heart do the superior and inferior venae cavae return blood?; The right atrium. What do the external jugular veins drain blood from?; The face, scalp, and superficial neck. What do the internal jugular veins drain blood from?; The brain, and deep portions of the face and neck. What are the two systems of veins that drain the upper limb and shoulder?; Deep set of veins and superficial set of veins. What is the pathway of the deep set of veins in the upper limb?; Digital veins → radial and ulnar veins → brachial veins. What is the pathway of the superficial set of veins in the upper limb?; Anastomoses in palm and wrist → basilic and cephalic veins. Which veins do the basilic and cephalic veins join?; Basilic vein joins brachial vein, and cephalic vein joins axillary vein. Which veins do the digital veins drain into in the deep set of veins?; Radial and ulnar veins. Which veins do the radial and ulnar veins drain into in the deep set of veins?; Brachial veins. Where do the anastomoses in the superficial set of veins occur?; In the palm and wrist. Which vein does the basilic vein join?; Brachial vein. Which vein does the cephalic vein join?; Axillary vein. Which veins drain the abdominal and thoracic walls?; Tributaries of the brachiocephalic and azygos veins. Into which vein does the azygos vein drain directly?; The superior vena cava. What is the role of the azygos vein?; It drains the abdominal and thoracic walls and empties into the superior vena cava. What are the main tributaries of the brachiocephalic veins?; Veins from the abdominal and thoracic walls. What is unusual about portal veins?; They do not transport blood directly to the heart. What unique venous pathway drains the abdominal viscera?; The hepatic portal system. Which organs' capillaries drain into the hepatic portal vein?; Stomach, intestines, pancreas, and spleen. Where does the hepatic portal vein transport blood for processing?; To the liver. After processing in the liver, where is the blood delivered?; To the inferior vena cava. What is a portal system?; A system that filters blood through 2 sets of capillaries instead of the usual 1 set. Name two examples of portal systems in the human body.; Hepatic Portal System and Renal Portal System. What unique function does the second set of capillaries in a portal system perform?; It performs a unique function in the body by filtering blood through an additional set of capillaries. What is the primary function of the Hepatic Portal System?; To filter blood from the gastrointestinal tract and spleen through the liver. What is the primary function of the Renal Portal System?; To filter blood through the kidneys. Into which groups do veins from the lower limb drain?; Deep and superficial groups of veins. What is the sequence of veins in the deep set from the foot to the external iliac vein?; Veins in foot → anterior and posterior tibial veins → popliteal vein → femoral vein → external iliac vein. What is the sequence of veins in the superficial set from the foot?; Veins in foot → small and great saphenous veins. Which vein is the longest in the body?; The great saphenous vein. Which veins in the foot drain into the anterior and posterior tibial veins?; Veins in the foot. Into which vein do the anterior and posterior tibial veins drain?; The popliteal vein. Into which vein does the popliteal vein drain?; The femoral vein. Into which vein does the femoral vein drain?; The external iliac vein. Which veins in the foot drain into the small and great saphenous veins?; Veins in the foot. What happens to cholesterol in the blood vessels as people age?; Cholesterol deposition in the blood vessels increases. What happens to coronary arteries with age?; Coronary arteries become narrowed. How can the heart change in size due to disease?; The heart may shrink slightly or enlarge due to disease. What happens to the proportion of the heart consisting of cardiac muscle as people age?; The proportion of the heart consisting of cardiac muscle declines. What type of tissue increases in the heart with age?; Fibrous connective tissue increases in the heart. What happens to the adipose tissue in the heart as people age?; Adipose tissue in the heart increases. Which parts of the heart may thicken with age?; Heart valves and the left ventricular wall may thicken. What happens to systolic blood pressure as people age?; Systolic blood pressure increases. What happens to the resting heart rate with age?; The resting heart rate decreases. What happens to the lumens of large arteries as people age?; The lumens of large arteries narrow as arterial walls thicken. What happens to arterial elasticity with age?; Arterial elasticity decreases. What factors contribute to cardiovascular disease?; Both environmental and hereditary factors. What is Marfan syndrome?; A connective tissue defect involving an abnormal type of the protein fibrillin, which can weaken the wall of the aorta and result in its bursting and sudden death. What protein is abnormal in Marfan syndrome?; Fibrillin. What is Familial hypertrophic cardiomyopathy?; An inherited overgrowth of myocardium caused by an abnormal myosin chain in cardiac muscle, which can result in sudden death. What defect causes Familial hypertrophic cardiomyopathy?; A myosin defect. What is the result of an inherited deficiency of a mitochondrial enzyme that breaks down fatty acids?; Heart failure due to the inability to break down long-chain fatty acids and use them for energy. What is the primary energy source for cardiac muscle?; Long-chain fatty acids. What is Familial hypercholesterolemia?; A condition where abnormal LDL receptors on liver cells do not take up cholesterol from the blood, resulting in high cholesterol and coronary artery disease. What is the consequence of abnormal LDL receptors in Familial hypercholesterolemia?; High cholesterol and coronary artery disease. What is Coronary Artery Disease (CAD)?; A disease involving deposition of cholesterol plaque on inner walls of coronary arteries. What does Coronary Artery Disease lead to?; Obstruction of coronary arteries and O2 deficiency in cardiac muscle. What conditions often accompany Coronary Artery Disease?; High serum cholesterol and hypertension. What is the term for chest pain caused by exertion in Coronary Artery Disease?; Angina pectoris. What major health event is Coronary Artery Disease a contributing factor to?; Myocardial infarction (heart attack). What are two treatments for Coronary Artery Disease?; Percutaneous transluminal coronary angioplasty (PTCA) and coronary bypass surgery. Where is the aortic valve best heard?; In the second intercostal space right of the sternum. Where is the pulmonary valve best heard?; In the second intercostal space left of the sternum. Where is the tricuspid valve best heard?; At the fifth intercostal space left of the sternum. Where is the mitral valve best heard?; In the fifth intercostal space on the left at the nipple line. Where can the pulse of the temporal artery be taken?; Anterior to the ear. Where is the pulse of the carotid artery measured?; In the inferior medial portion of the neck. Where can the pulse of the brachial artery be taken?; In the distal brachial region on the anterior side. Where is the pulse of the radial artery measured?; On the lateral side of the wrist on the anterior side. Where can the pulse of the femoral artery be taken?; In the inguinal region. Where is the pulse of the popliteal artery measured?; In the popliteal region. Where can the pulse of the dorsalis pedis artery be taken?; In the anterior ankle. Where is the pulse of the posterior tibia artery measured?; In the posterior ankle. What are the functions of the organs of the cardiovascular system?; The organs of the cardiovascular system function to transport nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes (carbon dioxide, nitrogenous wastes). What are the coverings of the heart?; The coverings of the heart include the pericardium, which consists of the fibrous pericardium and the serous pericardium. What are the layers that compose the wall of the heart?; The layers that compose the wall of the heart are the epicardium, myocardium, and endocardium. What are the major parts of the heart?; The major parts of the heart include the atria, ventricles, valves (tricuspid, pulmonary, mitral, and aortic), and septum. What is the function of the atria in the heart?; The atria receive blood returning to the heart from the body and lungs. What is the function of the ventricles in the heart?; The ventricles pump blood out of the heart to the lungs and the rest of the body. What is the function of the heart valves?; The heart valves ensure unidirectional blood flow through the heart. What is the pathway of blood through the heart?; Blood flows from the right atrium to the right ventricle, then to the lungs via the pulmonary arteries, returns to the left atrium via the pulmonary veins, and then to the left ventricle, which pumps it out to the body through the aorta. What is coronary circulation?; Coronary circulation is the circulation of blood in the blood vessels of the heart muscle (myocardium). What is the cardiac cycle?; The cardiac cycle is the sequence of events in one heartbeat, including systole (contraction) and diastole (relaxation) of the atria and ventricles. How are heart sounds produced?; Heart sounds are produced by the closing of the heart valves; the 'lub' sound is caused by the closure of the AV valves, and the 'dub' sound is caused by the closure of the semilunar valves. What are the parts of a normal ECG pattern?; The parts of a normal ECG pattern include the P wave, QRS complex, and T wave. What is the significance of the P wave in an ECG pattern?; The P wave represents atrial depolarization. What does the QRS complex in an ECG pattern signify?; The QRS complex represents ventricular depolarization. What does the T wave in an ECG pattern indicate?; The T wave represents ventricular repolarization. How is the cardiac cycle controlled?; The cardiac cycle is controlled by the sinoatrial (SA) node, atrioventricular (AV) node, and the conduction system of the heart. What are the major types of blood vessels?; The major types of blood vessels are arteries, veins, and capillaries. How do the structures of arteries and veins differ?; Arteries have thicker walls and more elastic tissue compared to veins, which have thinner walls and valves to prevent backflow. What is the primary function of capillaries?; The primary function of capillaries is to facilitate the exchange of substances between blood and tissue fluid. How are substances exchanged between blood in capillaries and tissue fluid?; Substances are exchanged between blood in capillaries and tissue fluid through diffusion, filtration, and osmosis. How is blood pressure produced?; Blood pressure is produced by the force of the heart pumping blood and the resistance of blood vessels. What mechanisms aid in returning venous blood to the heart?; Mechanisms that aid in returning venous blood to the heart include the skeletal muscle pump, respiratory pump, and venous valves. What are the two circuits of the cardiovascular system?; The pulmonary and systemic circuits. What is the function of the pulmonary circuit?; The pulmonary circuit carries blood between the heart and the lungs. What is the function of the systemic circuit?; The systemic circuit carries blood between the heart and the rest of the body. What are the major components of the arterial system?; The major arteries. What are the major components of the venous system?; The major veins. What changes occur in the cardiovascular system over a lifespan?; Various structural and functional changes.
What does the prefix 'angio-' refer to?; Vessel What is angiotensin?; A substance that constricts blood vessels. What does the prefix 'ather-' refer to?; Porridge What is atherosclerosis?; Deposits of plaque in arteries. What does the prefix 'brady-' refer to?; Slow What is bradycardia?; Abnormally slow heartbeat. What does the prefix 'diastol-' refer to?; Dilation What is diastolic pressure?; Blood pressure when the ventricle of the heart is relaxed. What does the prefix 'edem-' refer to?; Swelling What is edema?; Accumulation of fluids in the tissues that causes them to swell. What does the suffix '-gram' refer to?; Something written What is an electrocardiogram?; Recording of the electrical changes in the myocardium during a cardiac cycle. What does the prefix 'lun-' refer to?; Moon What is a semilunar valve?; A valve with crescent-shaped flaps. What does the prefix 'myo-' refer to?; Muscle What is the myocardium?; Muscle tissue within the wall of the heart. What does the prefix 'papill-' refer to?; Nipple What is a papillary muscle?; A small mound of muscle projecting into a ventricle of the heart. What does the prefix 'phleb-' refer to?; Vein What is phlebitis?; Inflammation of a vein. What does the prefix 'scler-' refer to?; Hard What is arteriosclerosis?; Loss of elasticity and hardening of a blood vessel wall. What does the prefix 'syn-' refer to?; Together What is a syncytium?; A mass of merging cells that act together. What does the prefix 'systol-' refer to?; Contraction What is systolic pressure?; Blood pressure resulting from a single ventricular contraction. What does the prefix 'tachy-' refer to?; Rapid What is tachycardia?; Abnormally fast heartbeat. How many liters of blood does the heart pump through the body each day?; 7,000 liters. How many times does the heart contract in an average lifetime?; 2.5 billion times. In what order does the heart pump blood through the blood vessels?; Arteries → arterioles → capillaries → venules → veins → back to heart. What makes up the cardiovascular system?; The heart and all blood vessels. What does the term 'cardiovascular' refer to?; Both heart and blood vessels. What is the function of the heart's pumping action?; To transport blood through blood vessels. How many circuits do blood vessels form in the cardiovascular system?; Two circuits. What is the function of the pulmonary circuit?; To transport oxygen-poor blood from the heart to the lungs and back to the heart. What happens to the blood in the lungs during the pulmonary circuit?; Blood picks up O2 and drops off CO2. What is the function of the systemic circuit?; To transport oxygen-rich blood from the heart to all body cells and back to the heart. What does the blood deliver to cells in the systemic circuit?; Nutrients. What does the blood remove from cells in the systemic circuit?; Wastes. What type of blood does the left side of the heart contain?; Oxygen-rich blood. What type of blood does the right side of the heart contain?; Oxygen-poor blood. What are the two circuits through which blood runs?; Pulmonary circuit to lungs and systemic circuit to body cells. Where does the pulmonary circuit transport blood?; To the lungs. Where does the systemic circuit transport blood?; To body cells. What shape is the heart?; Hollow, cone-shaped. Where is the heart located?; In the mediastinum of the thoracic cavity, superior to the diaphragm. How many chambers does the heart have?; 4 chambers. What are the upper chambers of the heart called?; Atria. What are the lower chambers of the heart called?; Ventricles. What is the function of the ventricles?; Pumping action. How does heart size vary?; Heart size varies with body size. Where does the heart lie in the body?; The heart lies in the thoracic cavity. What is the average size of the heart?; The average size of the heart is 14 cm long and 9 cm wide. Where is the heart located in relation to the sternum?; The heart is located posterior to the sternum. Where is the heart located in relation to the lungs?; The heart is located medial to the lungs. Where is the heart located in relation to the vertebral column?; The heart is located anterior to the vertebral column. Where does the base of the heart lie?; The base of the heart lies beneath the 2nd rib. Where does the apex of the heart lie?; The apex of the heart lies at the 5th intercostal space. Where is the heart located in the human body?; The heart is located in the thoracic cavity, between the lungs, and behind the sternum. What structure is directly in front of the heart?; The sternum. What is the name of the lower pointed end of the heart?; The apex of the heart. What is the name of the upper part of the heart?; The base of the heart. What structure lies directly below the heart?; The diaphragm. What is the pericardium?; A covering over the heart and large blood vessels. What is the fibrous pericardium?; The outer layer that surrounds the double-layered serous membrane. Where is the parietal pericardium located?; Deep to the fibrous pericardium; it is the outer layer of the serous membrane. What is the visceral pericardium also known as?; The epicardium. What is the function of the visceral pericardium?; It is the inner layer of the serous membrane and is attached to the surface of the heart. What are the three distinct layers of the heart wall?; Epicardium, Myocardium, and Endocardium. What is another name for the epicardium?; Visceral pericardium. Which layer of the heart wall is the outer layer?; Epicardium. Which layer of the heart wall is the middle layer?; Myocardium. Which layer of the heart wall is the inner layer?; Endocardium. What type of tissue composes the myocardium?; Cardiac muscle tissue. Which layer of the heart wall is the thickest?; Myocardium. What does the endocardium form?; The inner lining of all heart chambers. Which layer of the heart wall is described as a thin layer?; Both the epicardium and endocardium are thin layers. What is the composition of the epicardium (visceral pericardium)?; Serous membrane of connective tissue covered with epithelium and including blood capillaries, lymph capillaries, and nerve fibers. What is the function of the epicardium (visceral pericardium)?; Forms a protective outer covering; secretes serous fluid. What type of tissue makes up the myocardium?; Cardiac muscle tissue separated by connective tissue and including blood capillaries, lymph capillaries, and nerve fibers. What is the primary function of the myocardium?; Contracts to pump blood from the heart chambers. What is the composition of the endocardium?; Membrane of epithelium and underlying connective tissue, including blood vessels. What is the function of the endocardium?; Forms a protective inner lining of the chambers and valves. How many chambers does the heart have?; 4 chambers (2 atria and 2 ventricles). What are the characteristics of the atria?; Thin-walled upper chambers; receive blood returning to the heart. What are auricles and their function?; Flap-like projections from atria, which allow atrial expansion. What are the characteristics of the ventricles?; Thick-walled lower chambers; pump blood into arteries. What is the function of the right atrium?; Receives blood returning from the systemic circuit (from the superior and inferior vena cavae and coronary sinus); pumps blood to the right ventricle. What is the function of the right ventricle?; Receives blood from the right atrium; pumps blood to the lungs. What is the function of the left atrium?; Receives blood from the pulmonary veins; pumps blood to the left ventricle. What is the function of the left ventricle?; Receives blood from the left atrium; pumps blood to the systemic circuit. Where is the tricuspid valve located?; Right atrioventricular orifice. What is the function of the tricuspid valve?; Prevents blood from moving from the right ventricle into the right atrium during ventricular contraction. Where is the pulmonary valve located?; Entrance to pulmonary trunk. What is the function of the pulmonary valve?; Prevents blood from moving from the pulmonary trunk into the right ventricle during ventricular relaxation. Where is the mitral valve located?; Left atrioventricular orifice. What is the function of the mitral valve?; Prevents blood from moving from the left ventricle into the left atrium during ventricular contraction. Where is the aortic valve located?; Entrance to aorta. What is the function of the aortic valve?; Prevents blood from moving from the aorta into the left ventricle during ventricular relaxation. What is the function of the superior vena cava?; It carries deoxygenated blood from the upper body to the right atrium of the heart. What is the role of the aorta in the cardiovascular system?; It carries oxygenated blood from the left ventricle to the rest of the body. Where does the right pulmonary artery transport blood?; It transports deoxygenated blood from the right ventricle to the lungs. What is the function of the left pulmonary veins?; They carry oxygenated blood from the lungs to the left atrium. What is the purpose of the tricuspid valve?; It prevents backflow of blood from the right ventricle to the right atrium. What is the role of the mitral (bicuspid) valve?; It prevents backflow of blood from the left ventricle to the left atrium. What is the function of the pulmonary valve?; It prevents backflow of blood from the pulmonary artery into the right ventricle. What is the interventricular septum?; It is the wall that separates the left and right ventricles of the heart. What is the function of the papillary muscles?; They contract to prevent inversion or prolapse of the atrioventricular valves during ventricular contraction. What is the role of the chordae tendineae?; They anchor the atrioventricular valves to the papillary muscles and prevent valve inversion. What is the function of the left ventricle?; It pumps oxygenated blood into the aorta for distribution to the body. What is the function of the right ventricle?; It pumps deoxygenated blood into the pulmonary artery for oxygenation in the lungs. What is the role of the inferior vena cava?; It carries deoxygenated blood from the lower body to the right atrium of the heart. What is the function of the tricuspid valve?; The tricuspid valve prevents backflow of blood from the right ventricle to the right atrium. Where is the mitral (bicuspid) valve located?; The mitral (bicuspid) valve is located between the left atrium and the left ventricle. What is the role of the aortic valve?; The aortic valve prevents backflow of blood from the aorta into the left ventricle. What is the function of the pulmonary valve?; The pulmonary valve prevents backflow of blood from the pulmonary artery into the right ventricle. What structures are labeled in the photo of the human tricuspid valve?; Right atrium, cusps of tricuspid valve, chordae tendineae, interventricular septum, papillary muscles, muscular ridges. What structures surround the origins of the pulmonary trunk and aorta, and orifices between atria and ventricles?; Rings of dense connective tissue. What is the function of the rings of dense connective tissue in the heart?; They provide attachments for heart valves and muscle fibers and prevent excess dilation of heart chambers during contraction. What prevents excess dilation of heart chambers during contraction?; Rings of dense connective tissue. What makes up the skeleton of the heart?; Rings of dense connective tissue and other fibrous masses in the interventricular septum. Where are the fibrous masses that contribute to the skeleton of the heart located?; In the interventricular septum. What is the first step in the blood flow through the heart?; Blood from the systemic circuit enters the right atrium. Which valve does blood pass through after the right atrium?; Tricuspid valve. Where does blood go after the right ventricle?; Pulmonary trunk. What is the function of the pulmonary arteries?; To carry blood from the heart to the lungs. Where does blood go after passing through the pulmonary capillaries in the lungs?; Pulmonary veins. Which chamber of the heart receives blood from the pulmonary veins?; Left atrium. Through which valve does blood pass after the left atrium?; Mitral (bicuspid) valve. Where does blood go after the left ventricle?; Aorta. What is the final step in the blood flow through the heart?; Blood is distributed to the systemic circuit. What is the role of the aortic valve?; To prevent backflow of blood from the aorta into the left ventricle. What is the function of the superior vena cava?; To carry deoxygenated blood from the upper body to the right atrium. What is the function of the inferior vena cava?; To carry deoxygenated blood from the lower body to the right atrium. What is the role of alveolar capillaries in the lungs?; To facilitate gas exchange between the blood and the air in the lungs. Which arteries supply blood to the tissues of the heart?; The left and right coronary arteries. What are the first two branches of the aorta?; The coronary arteries. Where do the coronary arteries originate from?; The aorta. What are the two main arteries that supply blood to the heart?; Right coronary artery and left coronary artery. Which artery branches off the right coronary artery to supply the ventricular walls?; Posterior interventricular artery. Which artery branches off the right coronary artery to supply the walls of the right atrium and right ventricle?; Marginal artery. Which artery branches off the left coronary artery to supply the walls of the left atrium and left ventricle?; Circumflex artery. Which artery branches off the left coronary artery to supply the ventricular walls?; Anterior interventricular artery. Where do the myocardial capillaries in the ventricular walls drain into?; Cardiac veins. Where do the cardiac veins drain into?; Coronary sinus. Where does the coronary sinus drain into?; Right atrium. What is the function of the aorta?; The aorta is the main artery that carries blood from the heart to the rest of the body. Where does the superior vena cava transport blood?; The superior vena cava transports deoxygenated blood from the upper body to the right atrium of the heart. What is the role of the right pulmonary artery?; The right pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. What is the function of the left pulmonary veins?; The left pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. What is the pulmonary trunk?; The pulmonary trunk is a major vessel that originates from the right ventricle and splits into the left and right pulmonary arteries. What is the left auricle?; The left auricle is a small, ear-shaped pouch that projects from the left atrium. What is the function of the left coronary artery?; The left coronary artery supplies blood to the left side of the heart muscle. What is the great cardiac vein?; The great cardiac vein collects deoxygenated blood from the heart muscle and returns it to the right atrium. What is the anterior interventricular artery?; The anterior interventricular artery, also known as the left anterior descending artery, supplies blood to the front of the left side of the heart. What is the function of the right atrium?; The right atrium receives deoxygenated blood from the body through the superior and inferior vena cava. What is the role of the right ventricle?; The right ventricle pumps deoxygenated blood to the lungs through the pulmonary arteries. What is the coronary sinus?; The coronary sinus is a large vein that collects blood from the heart muscle and empties into the right atrium. What is the function of the left ventricle?; The left ventricle pumps oxygenated blood to the rest of the body through the aorta. What is the apex of the heart?; The apex of the heart is the pointed end of the heart that is directed downward, forward, and to the left. What is the function of the right coronary artery?; The right coronary artery supplies blood to the right side of the heart muscle. What is the role of the inferior vena cava?; The inferior vena cava transports deoxygenated blood from the lower body to the right atrium of the heart. What is the posterior interventricular artery?; The posterior interventricular artery supplies blood to the posterior part of the heart. What is the cardiac cycle?; The events of a heartbeat. How do the heart chambers function during the cardiac cycle?; In a coordinated manner. What happens during atrial systole?; The atria contract while the ventricles relax (ventricular diastole). What happens during ventricular systole?; The ventricles contract while the atria relax (atrial diastole). What is atrial diastole?; The relaxation of the atria. What is ventricular diastole?; The relaxation of the ventricles. What is a heart transplant?; Replacement of most of a failing heart with a donor heart. What is a Left Ventricular Assist Device (LVAD)?; A mechanical half-heart, used in some cases temporarily, until a donor heart is available. What is an implantable replacement heart made of?; Titanium and plastic. Who typically receives an implantable replacement heart?; People who cannot have a heart transplant and do not have long to live. What does stem cell technology allow in terms of cardiac muscle tissue?; Cardiac muscle tissue can now be cultured from altered somatic cells or from stem cells. What future application might stem cell technology enable for heart treatment?; Stem cell heart patches. What happens to the pressure in the heart chambers during a cardiac cycle?; The pressure in the heart chambers rises and falls. What causes the heart valves to open and close during the cardiac cycle?; Pressure changes in the heart chambers. What happens to the ventricles during atrial systole and ventricular diastole?; The ventricles are relaxed. Which valves are open and which are closed during atrial systole and ventricular diastole?; The A-V valves are open and the semilunar valves are closed. What percentage of blood flows passively from the atria into the ventricles during atrial systole and ventricular diastole?; About 70% of blood. What happens to the remaining 30% of blood during atrial systole?; Atrial systole pushes the remaining 30% of blood into the ventricles, causing ventricular pressure to increase. What happens to the A-V valves during ventricular systole and atrial diastole?; The A-V valves close. What prevents the cusps of the valves from bulging too far backward into the atria during ventricular systole?; The chordae tendineae. What happens to the atria during ventricular systole and atrial diastole?; The atria relax. Where does blood flow into the atria from during ventricular systole and atrial diastole?; From the venae cavae and pulmonary veins. What happens to the ventricular pressure during ventricular systole?; The ventricular pressure increases and opens the semilunar valves. Where does blood flow during ventricular systole?; Blood flows into the pulmonary trunk and aorta. What does a heartbeat through a stethoscope sound like?; Lubb-dupp What causes the sounds heard in a heartbeat?; Closing of heart valves and vibrations associated with a sudden slowing of blood flow during contraction/relaxation of chambers What is the first heart sound called?; Lubb When does the 'lubb' sound occur?; During ventricular systole What is the 'lubb' sound associated with?; Closing of the A-V valves What is the second heart sound called?; Dupp When does the 'dupp' sound occur?; During ventricular diastole What is the 'dupp' sound associated with?; Closing of the pulmonary and aortic semilunar valves What is a murmur?; An abnormal heart sound derived from incomplete closure of cusps of a valve Where can the sounds of the aortic valve be heard?; In the aortic area, located at the second intercostal space to the right of the sternum. Where can the sounds of the pulmonary valve be heard?; In the pulmonary area, located at the second intercostal space to the left of the sternum. Where can the sounds of the tricuspid valve be heard?; In the tricuspid area, located at the fourth intercostal space to the left of the sternum. Where can the sounds of the mitral valve be heard?; In the mitral area, located at the fifth intercostal space at the midclavicular line. What type of networks do cardiac muscle cells form?; Branching networks. What do intercalated discs between cardiac muscle cells contain?; Gap junctions. What is the function of gap junctions in cardiac muscle cells?; They allow action potentials to spread through a network of cells. What is a functional syncytium in cardiac muscle fibers?; A mass of merging cells that function as a unit. How many functional syncytia exist in the heart?; Two. Where is the atrial syncytium located?; In the atrial walls. Where is the ventricular syncytium located?; In the ventricular walls. What is the cardiac conduction system?; A group of clumps and strands of specialized cardiac muscle tissue, which initiates and distributes impulses throughout the myocardium. What is the function of the cardiac conduction system?; It coordinates the events of the cardiac cycle. What is the first component of the cardiac conduction system?; SA node. What follows the SA node in the cardiac conduction system?; Atrial syncytium. What follows the atrial syncytium in the cardiac conduction system?; Junctional fibers. What follows the junctional fibers in the cardiac conduction system?; AV node. What follows the AV node in the cardiac conduction system?; AV bundle. What follows the AV bundle in the cardiac conduction system?; Bundle branches. What follows the bundle branches in the cardiac conduction system?; Purkinje fibers. What follows the Purkinje fibers in the cardiac conduction system?; Ventricular syncytium. What is the role of the SA (Sinoatrial) Node in the cardiac conduction system?; It acts as the pacemaker and initiates rhythmic contractions of the heart. What is the function of the Internodal Atrial Muscle?; It conducts impulses from the SA node to the atria. What do Junctional Fibers do in the cardiac conduction system?; They conduct impulses from the SA node to the AV node. What is the role of the AV (Atrioventricular) Node?; It conducts impulses to the AV Bundle and delays the impulse so that the atria finish contracting before the ventricles contract. What is the function of the AV (Atrioventricular) Bundle (of His)?; It conducts impulses rapidly between the SA node and the bundle branches. What is the role of the Left and Right Bundle Branches?; They split off from the AV bundle and conduct impulses to the Purkinje fibers on both sides of the heart. What do Purkinje Fibers do in the cardiac conduction system?; They are large fibers that conduct impulses to the ventricular myocardium. What are the major components of the cardiac conduction system?; SA node, AV node, AV bundle, right bundle branch, left bundle branch, Purkinje fibers. What happens when Purkinje fibers stimulate muscle cells in the ventricles?; The ventricles contract with a twisting motion. Where are the whorled networks of muscle located in the heart?; In the walls of the ventricles. What is the function of the SA node in the cardiac conduction system?; It acts as the natural pacemaker of the heart, initiating the heartbeat. What role does the AV node play in the cardiac conduction system?; It delays the electrical impulse before it passes to the ventricles, ensuring the atria contract before the ventricles. What is the function of the AV bundle in the cardiac conduction system?; It transmits the electrical impulses from the AV node to the bundle branches. What is the role of the right and left bundle branches in the cardiac conduction system?; They conduct impulses through the interventricular septum to the Purkinje fibers. What is the significance of the twisting motion of the ventricles during contraction?; It helps to efficiently pump blood out of the ventricles. What does an electrocardiogram (ECG or EKG) record?; Electrical changes that occur in the myocardium during the cardiac cycle. What is the primary use of an electrocardiogram?; To assess the heart’s ability to conduct impulses. What does the P wave in an ECG represent?; Atrial depolarization; occurs just prior to atrial contraction. What does the QRS complex in an ECG represent?; Ventricular depolarization; occurs just prior to ventricular contraction. What does the T wave in an ECG represent?; Ventricular repolarization; occurs just prior to ventricular relaxation. Why is the record of atrial repolarization not visible in an ECG?; It is 'hidden' in the large QRS complex, since ventricular depolarization is a much larger event. What does Figure 15.19 illustrate?; The relationship between the ECG and the phases of the cardiac cycle. What is represented by the P wave in an ECG?; Atrial depolarization. What occurs during the QRS complex in an ECG?; Ventricular depolarization. What does the T wave in an ECG represent?; Ventricular repolarization. What phase of the cardiac cycle is associated with the P wave?; Atrial systole. During which phase of the cardiac cycle does the QRS complex occur?; Ventricular systole. What phase of the cardiac cycle is associated with the T wave?; Ventricular diastole. What happens to the atria during the QRS complex?; Atrial repolarization. What is the significance of the PR interval in an ECG?; It represents the time between the onset of atrial depolarization and the onset of ventricular depolarization. What does the ST segment in an ECG indicate?; The period when the ventricles are depolarized. What does the first graph in Figure 15.20 represent?; Pressure changes in the aorta, ventricles, and atria during the cardiac cycle. What does the second graph in Figure 15.20 show?; Ventricular volume changes during the cardiac cycle. What does the third graph in Figure 15.20 depict?; Electrocardiogram (ECG) readings during the cardiac cycle. What does the fourth graph in Figure 15.20 illustrate?; Heart sounds during the cardiac cycle. What event is indicated by the opening of the AV valve in Figure 15.20?; The beginning of ventricular filling. What does the closing of the AV valve signify in Figure 15.20?; The end of ventricular filling and the beginning of ventricular systole. What does the opening of the aortic valve indicate in Figure 15.20?; The beginning of ventricular ejection. What does the closing of the aortic valve signify in Figure 15.20?; The end of ventricular ejection and the beginning of ventricular diastole. What is the significance of the P wave in the ECG graph of Figure 15.20?; Atrial depolarization. What does the QRS complex represent in the ECG graph of Figure 15.20?; Ventricular depolarization. What does the T wave indicate in the ECG graph of Figure 15.20?; Ventricular repolarization. What causes the first heart sound (S1) in Figure 15.20?; The closing of the AV valves. What causes the second heart sound (S2) in Figure 15.20?; The closing of the aortic and pulmonary valves. What node normally controls the heart rate?; The SA node. Which fibers modify the heart rate in response to changing conditions?; Sympathetic and parasympathetic fibers. Name some conditions that can modify the heart rate.; Physical exercise, body temperature, fight-or-flight, and concentration of various ions such as K+ and Ca+2. How do parasympathetic impulses affect the heart rate?; Parasympathetic impulses via vagus nerves decrease heart rate due to influence on SA and AV nodes. How do sympathetic impulses affect the heart rate?; Sympathetic impulses via accelerator nerves increase heart rate due to influence on SA and AV nodes, and ventricular myocardium. Where do baroreceptor reflexes arise from?; From the cardiac control center in the medulla oblongata. What is the function of baroreceptor reflexes?; To balance inhibitory and excitatory effects of parasympathetic and sympathetic fibers. What does the cardiac control center regulate?; It regulates autonomic impulses to the heart. What is the function of baroreceptors in the cardiovascular system?; Baroreceptors detect changes in blood pressure and send signals to the central nervous system. Where are the baroreceptors located in the cardiovascular system?; Baroreceptors are located in the carotid sinuses and the aortic arch. What is the role of the central nervous system in the baroreceptor reflex?; The central nervous system processes signals from baroreceptors and sends autonomic impulses to alter heart action. What type of neurons carry signals from baroreceptors to the central nervous system?; Sensory or afferent neurons. What type of neurons carry signals from the central nervous system to the heart in the baroreceptor reflex?; Motor or efferent neurons. How do autonomic impulses affect the heart in the baroreceptor reflex?; Autonomic impulses alter heart action to regulate blood pressure. What is the general pathway of the baroreceptor reflex?; Receptor (baroreceptors) → Sensory neuron → Central nervous system → Motor neuron → Effector (heart). What is the effector in the baroreceptor reflex arc?; The heart. What are arrhythmias?; Altered heart rhythms. What is fibrillation?; Uncoordinated, chaotic contraction of small areas of myocardium. Is atrial fibrillation life-threatening?; No, atrial fibrillation is not life-threatening. Is ventricular fibrillation life-threatening?; Yes, ventricular fibrillation is often fatal. What is tachycardia?; Abnormally fast heartbeat, >100 beats/min at rest. What is bradycardia?; Abnormally slow heartbeat, <60 beats/min at rest. What is flutter?; Rapid, regular contraction of a heart chamber, 250-350 beats/min. What is a premature beat?; A beat that occurs before expected in the normal cardiac cycle, often originating from ectopic regions of the heart (other than SA node). What is an ectopic pacemaker?; When damage to the SA node leads to the AV node taking over and acting as a secondary pacemaker, with a rate of 40-60 beats/min instead of 70-80. What is an artificial pacemaker?; A device used to treat disorders of the cardiac conduction system; it is implantable and battery-powered. What are blood vessels?; Organs of the cardiovascular system. What is the function of blood vessels?; To form a closed circuit, transporting blood from the heart to body cells (or lungs) and back to the heart. What do arteries do?; Carry blood away from the ventricles of the heart. What is the function of arterioles?; Receive blood from the arteries and carry it to the capillaries. What is the role of capillaries?; Sites of exchange of substances between the blood and the body cells. What do venules do?; Receive blood from the capillaries and conduct it to veins. What is the function of veins?; Receive blood from venules and carry it back to the atria of the heart. What are the two types of blood vessels shown in Figure 15.23?; Arteriole (bottom) and Venule (top). What is the function of the endothelium in blood vessels?; The endothelium lines the interior surface of blood vessels, providing a smooth surface for blood flow. What type of tissue is found in the tunica media of blood vessels?; The tunica media contains smooth muscle tissue. What is the role of valves in veins?; Valves in veins prevent the backflow of blood, ensuring it flows in one direction towards the heart. What is the outermost layer of a blood vessel called?; The outermost layer is called the tunica externa. What is the lumen in a blood vessel?; The lumen is the central cavity through which blood flows. What type of connective tissue is found in the tunica media?; The tunica media contains elastic and collagen fibers. What is the primary difference between arterioles and venules?; Arterioles carry blood away from the heart and have thicker walls with more smooth muscle, while venules carry blood towards the heart and have thinner walls with less smooth muscle. What is angiogenesis?; Formation of new blood vessels. What mainly controls angiogenesis?; Vascular Endothelial Growth Factor (VEGF). Why is angiogenesis regulated in the body?; Because excess, deficient, or inappropriate blood vessel formation can cause common diseases. How does the body promote angiogenesis in response to a blocked coronary artery?; The body secretes VEGF. What can be done if the body's secretion of VEGF is not sufficient to promote angiogenesis?; VEGF may be delivered in time-release capsules. Why do tumors secrete VEGF?; To nourish themselves. What are antiangiogenesis drugs used to treat?; Cancer and age-related macular degeneration. What are the characteristics of artery walls?; Thick, strong walls, thicker than the walls of veins. What are the three layers or tunics of arteries?; Tunica interna (intima), Tunica media, Tunica externa (adventitia). What is the innermost layer of an artery called?; Tunica interna (intima). What is the composition of the tunica media in arteries?; Smooth muscle and elastic tissue. What is the outer layer of an artery called?; Tunica externa (adventitia). What type of tissue makes up the tunica externa (adventitia)?; Connective tissue. Under what condition do arteries transport blood?; Under high blood pressure. What do arteries give rise to?; Smaller arterioles. How do the walls of arterioles compare to those of arteries?; Arterioles have thinner walls than arteries but have the same three layers or tunics. What happens to the walls of arterioles as they become smaller?; The walls of the middle and outer layers become thinner as arterioles become smaller. What functions can both arteries and arterioles perform?; Both arteries and arterioles can undergo vasoconstriction and vasodilation. What is an arteriole?; A small blood vessel that branches out from an artery and leads to capillaries. What type of cells are found in the walls of arterioles?; Smooth muscle cells. What is the function of the precapillary sphincter?; It regulates blood flow into capillaries. What is the role of endothelium in arterioles?; It lines the interior surface of the blood vessels. How many muscle fibers do small arterioles contain in their walls?; Only a few muscle fibers. What are the smallest-diameter blood vessels?; Capillaries. What do capillaries connect?; The smallest arterioles and the smallest venules. What are capillaries extensions of?; The inner lining of arterioles. What do the walls of capillaries consist of?; Endothelium (simple squamous epithelium) only. Are capillaries permeable?; They are semi-permeable. What mainly regulates capillary blood flow?; Precapillary sphincters. What are precapillary sphincters?; Smooth muscle surrounding capillary when it branches off arteriole or metarteriole. How are substances exchanged in capillaries?; By diffusion. What are the openings in the walls of capillaries called?; Thin slits found where endothelial cells overlap. How does the size of openings in capillaries vary?; The sizes of openings vary among tissues. What determines the permeability of capillaries?; The size of the slits. What determines the density of capillary networks in a tissue?; The metabolic rate of the tissue. Which tissues have a rich capillary supply?; Muscle and nerve tissues. Why do muscle and nerve tissues have a rich capillary supply?; Because they use a large amount of O2 and nutrients. Which tissues have fewer capillaries?; Tissues with lower metabolic rates, such as cartilage. What is the primary function of capillaries?; To exchange gases, nutrients, and metabolic byproducts between blood and tissue around cells. What is the most important method of transfer in capillary exchange?; Diffusion. How do lipid-soluble substances diffuse in capillaries?; Through the cell membrane. How do water-soluble substances diffuse in capillaries?; Through membrane channels and slits. What forces molecules through the membrane during filtration in capillaries?; Hydrostatic pressure. Where does the pressure for filtration in capillaries come from?; From ventricular contraction. What creates osmotic pressure in capillaries?; The presence of impermeant solutes, such as plasma proteins, inside capillaries. What is the role of osmotic pressure in capillary exchange?; It draws water into capillaries, opposing filtration. What happens at the arteriolar end of a capillary during capillary exchange?; H2O and other substances leave the capillary because hydrostatic pressure is greater than osmotic pressure. What causes H2O and other substances to leave the capillary at the arteriolar end?; Hydrostatic pressure being greater than osmotic pressure. What happens at the venular end of a capillary during capillary exchange?; H2O enters the capillary because osmotic pressure is greater than hydrostatic pressure. What causes H2O to enter the capillary at the venular end?; Osmotic pressure being greater than hydrostatic pressure. What is the net outward force at the arteriolar end of a capillary?; 11 mm Hg (35 mm Hg outward force of hydrostatic pressure - 24 mm Hg inward force of osmotic pressure). What is the net inward force at the venular end of a capillary?; 8 mm Hg (24 mm Hg inward force of osmotic pressure - 16 mm Hg outward force of hydrostatic pressure). What are venules?; Microscopic vessels that transport blood from the capillaries to veins. How do the walls of venules compare to those of arterioles?; Venules have thinner walls and less smooth muscle than arterioles. How do the walls of veins compare to those of arteries?; Veins have thinner walls than arteries. How many layers or tunics do veins have?; Three layers or tunics. How is the tunica media of veins different from that of arteries?; The tunica media is less developed in veins. Under what pressure do veins carry blood?; Veins carry blood under relatively low pressure. What function do veins serve in addition to carrying blood?; Veins function as blood reservoirs. What special feature do many veins have?; Many veins have flap-like valves. What percentage of blood is in veins and venules at any time?; About 2/3 of blood. What is the percentage distribution of blood in systemic veins?; 60-70% What is the percentage distribution of blood in the lungs?; 10-12% What is the percentage distribution of blood in the heart?; 8-11% What is the percentage distribution of blood in systemic arteries?; 10-12% What is the percentage distribution of blood in capillaries?; 4-5% What are the three layers of an artery wall?; An endothelial lining, a middle layer of smooth muscle and elastic connective tissue, and an outer layer of connective tissue. What is the function of an artery?; Carries blood under relatively high pressure from the heart to arterioles. How does the wall of an arteriole compare to that of an artery?; An arteriole has a thinner wall than an artery but still has three layers; smaller arterioles have an endothelial lining, some smooth muscle tissue, and a small amount of connective tissue. What is the function of an arteriole?; Connects an artery to a capillary, helps control the blood flow into a capillary by vasoconstricting or vasodilating. What is the structure of a capillary wall?; A single layer of squamous epithelium. What is the function of a capillary?; Allows nutrients, gases, and wastes to be exchanged between the blood and tissue fluid. How does the wall of a venule compare to that of an arteriole?; A venule has a thinner wall than an arteriole, with less smooth muscle and elastic connective tissue. What is the function of a venule?; Connects a capillary to a vein. How does the wall of a vein compare to that of an artery?; A vein has a thinner wall than an artery but with similar layers; the middle layer is more poorly developed, and some veins have flap-like valves. What is the function of a vein?; Carries blood under relatively low pressure from a venule to the heart; valves prevent a backflow of blood; serves as a blood reservoir. What is atherosclerosis?; Deposits of cholesterol plaque form in the inner lining of walls of arteries. What is an aneurysm?; A bulge in the wall of an artery, formed when blood pressure dilates a weakened area of the vessel; can burst the wall of the artery. What is phlebitis?; Inflammation of a vein; common disorder. What are varicose veins?; Abnormal and irregular dilations in superficial veins; most common in legs. What is blood pressure?; The force the blood exerts against the inner walls of the blood vessels. What role does blood pressure play in the circulatory system?; Blood pressure circulates the blood. To which blood vessels does the term 'blood pressure' most commonly refer?; Systemic arteries. Is there blood pressure throughout the entire vascular system?; Yes, there is blood pressure throughout the vascular system. How does blood move through the vascular system?; Blood moves from higher to lower pressure throughout the system. When does arterial blood pressure rise?; When the ventricles contract. When does arterial blood pressure fall?; When the ventricles relax. What is systolic pressure (SP)?; The maximum pressure reached during ventricular contraction. What is diastolic pressure (DP)?; The minimum pressure remaining before the next ventricular contraction. What is pulse pressure (PP)?; The difference between systolic and diastolic blood pressures (SP - DP). What is mean arterial pressure (MAP)?; The average pressure in the arterial system; represents the average force driving blood to the tissues. How is mean arterial pressure (MAP) calculated?; MAP = DP + 1/3 PP. How is blood pressure typically stated?; As a fraction: SP/DP, as in 120/80. In what units is blood pressure measured?; mm Hg. What is typically used to measure arterial blood pressure?; A sphygmomanometer. What are the main components of a sphygmomanometer?; Air control valve, bulb, pressure gauge, inflatable cuff. What is the function of the inflatable cuff in a sphygmomanometer?; To apply pressure to the arm to measure blood pressure. What does the pressure gauge in a sphygmomanometer measure?; The arterial blood pressure. How is air controlled in a sphygmomanometer?; Using the air control valve. What is the purpose of the bulb in a sphygmomanometer?; To inflate the cuff by pumping air into it. What happens to blood pressure as the distance from the left ventricle increases?; Blood pressure decreases. What is the trend of systolic and diastolic pressure as blood moves away from the left ventricle?; Both systolic and diastolic pressures decrease. In which part of the circulatory system is the blood pressure the highest?; In the aorta. Where does the most significant drop in blood pressure occur in the circulatory system?; In the arterioles. What is the blood pressure trend in capillaries compared to arterioles?; Blood pressure continues to decrease in capillaries. How does blood pressure in veins compare to that in arteries?; Blood pressure in veins is much lower than in arteries. What is the blood pressure in the vena cava compared to the aorta?; Blood pressure in the vena cava is significantly lower than in the aorta. What are the sites for measuring the arterial pulse as shown in Figure 15.33?; Temporal artery, Carotid artery, Facial artery, Brachial artery, Radial artery, Femoral artery, Popliteal artery, Posterior tibial artery, Dorsalis pedis artery. Where is the temporal artery located for measuring the pulse?; On the side of the head near the temple. Where is the carotid artery located for measuring the pulse?; In the neck. Where is the facial artery located for measuring the pulse?; On the face, near the jawline. Where is the brachial artery located for measuring the pulse?; On the inner side of the upper arm. Where is the radial artery located for measuring the pulse?; On the wrist, near the thumb. Where is the femoral artery located for measuring the pulse?; In the groin area. Where is the popliteal artery located for measuring the pulse?; Behind the knee. Where is the posterior tibial artery located for measuring the pulse?; Near the ankle. Where is the dorsalis pedis artery located for measuring the pulse?; On the top of the foot. What happens to blood pressure when blood volume increases?; Blood pressure increases. How does an increase in heart rate affect blood pressure?; It increases blood pressure. What is the effect of increased stroke volume on blood pressure?; It increases blood pressure. What happens to blood pressure when blood viscosity increases?; Blood pressure increases. How does an increase in peripheral resistance affect blood pressure?; It increases blood pressure. What is stroke volume (SV)?; The volume of blood that enters the arteries with each ventricular contraction (~70 mL/beat). What is cardiac output (CO)?; The volume of blood discharged from a ventricle each minute. How is cardiac output (CO) calculated?; Cardiac output = Stroke volume × Heart rate (CO = SV × HR). What is the formula for cardiac output if stroke volume is 70 mL/beat and heart rate is 72 beats/min?; CO = 70 mL/beat × 72 beats/min = 5,040 mL/min. How does blood pressure vary with cardiac output?; Blood pressure varies directly with cardiac output. What happens to blood pressure if stroke volume (SV) or heart rate (HR) increases?; An increase in SV or HR causes an increase in CO, which increases blood pressure (BP). What constitutes blood volume?; The sum of volumes of plasma and formed elements. What factors cause blood volume to vary?; Age, body size, and gender. What is the average blood volume for adults?; About 5 liters (4 to 5 liters in a female and 5 to 6 liters in a male). What percentage of body weight does blood volume constitute?; 8% of body weight. How is blood pressure (BP) related to blood volume?; Blood pressure is directly proportional to blood volume. What can change blood pressure?; Any factor that changes blood volume. What happens to blood pressure when blood volume decreases due to hemorrhage?; Blood pressure decreases. What is Peripheral Resistance (PR)?; The force of friction between blood and the walls of blood vessels. What must blood pressure overcome in order to flow?; Peripheral Resistance (PR). How do factors that change Peripheral Resistance (PR) affect blood pressure?; Factors that change PR also change blood pressure. What effect does vasoconstriction of arterioles have on Peripheral Resistance (PR) and blood pressure?; Vasoconstriction of arterioles increases PR, which increases blood pressure. What happens to arteries when blood is pumped out of the ventricles?; Arteries swell and rapid elastic recoil sends the blood through the arteries, against PR in arterioles and capillaries. What is viscosity?; The difficulty with which molecules of fluid flow past each other. How does greater viscosity affect blood flow?; Greater viscosity increases the resistance to blood flow. What components increase the viscosity of blood?; Blood cells and plasma proteins. How does increased resistance to blood flow affect blood pressure?; Greater resistance to flow requires greater force to transport the blood, which increases blood pressure. What happens to blood viscosity and blood pressure when the concentration of blood cells or plasma proteins is altered?; Any factor that alters the concentration of blood cells or plasma proteins also alters blood viscosity, which in turn affects blood pressure. How does anemia affect blood viscosity and blood pressure?; Anemia lowers the concentration of blood cells, which lowers blood viscosity and subsequently lowers blood pressure. What determines blood pressure (BP)?; Cardiac output (CO) and peripheral resistance (PR). What is the formula for blood pressure?; BP = CO × PR What two factors need to be regulated to maintain blood pressure?; Cardiac output (CO) and peripheral resistance (PR). What happens to cardiac output when blood pressure increases?; Cardiac output increases. What stimulates baroreceptors in the aortic arch and carotid sinuses?; An increase in blood pressure. Where do sensory impulses go after baroreceptors are stimulated?; To the cardiac center. What type of impulses are sent to the heart to decrease heart rate?; Parasympathetic impulses. What effect does the inhibition of the SA node have on heart rate?; It decreases heart rate. What is the final result of the process that starts with increased cardiac output?; Blood pressure returns toward normal. What happens to the vasomotor center when blood pressure rises?; It is inhibited. What is the effect of less frequent sympathetic impulses to arteriole walls?; Vasodilation of arterioles. What happens to peripheral resistance when arterioles vasodilate?; Peripheral resistance decreases. What is the final result of the process that starts with rising blood pressure?; Blood pressure returns toward normal. What is hypertension?; Long-lasting elevated arterial blood pressure. What are some causes of hypertension?; Unknown cause, increased Na+ intake, psychological stress, obesity, kidney disease. Why is hypertension often called the 'silent killer'?; Because it may not cause any direct symptoms. How does hypertension contribute to cardiovascular diseases?; It contributes to the formation of atherosclerosis. What are some potential complications of hypertension?; Coronary thrombosis, embolism, cerebral thrombosis, embolism, hemorrhage, transient ischemic attack (TIA), cerebral vascular accident (CVA). What are some preventive measures for hypertension?; Healthy diet and weight, regular exercise, limiting Na+ intake. What are some treatments for hypertension?; Diuretics, sympathetic inhibitors. How does obesity contribute to hypertension?; By increasing peripheral resistance. How can kidney disease lead to hypertension?; Via the renin-angiotensin response. What happens to blood pressure as blood moves through the arterial system and into the capillary network?; Blood pressure decreases. Why is there little pressure remaining at the venous ends of the capillaries?; Because blood pressure decreases as blood moves through the arterial system and into the capillary network. Is venous blood flow solely a direct result of heart action?; No, it is only partly a direct result of heart action. What are the three factors that venous blood flow depends on?; Skeletal muscle contraction, breathing movements, and vasoconstriction of veins. How does skeletal muscle contraction affect venous blood flow?; Skeletal muscle contraction helps to push blood through the veins. How do breathing movements influence venous blood flow?; Breathing movements create pressure changes that help to move blood through the veins. What role does vasoconstriction of veins play in venous blood flow?; Vasoconstriction of veins helps to increase the pressure within the veins, aiding blood flow back to the heart. Where do all veins, except those returning to the heart from the lungs, drain into?; The right atrium. What is the pressure in the right atrium called?; Central venous pressure. What factors influence central venous pressure?; Factors that alter the flow of blood into the right atrium. How does central venous pressure affect peripheral veins?; It affects the pressure within the peripheral veins. What effect does a weakly beating heart have on central venous pressure?; It increases central venous pressure. What happens when there is an increase in central venous pressure?; Blood backs up into the peripheral veins. What can result from blood backing up into the peripheral veins?; Peripheral edema. What increases blood flow to the right atrium, thereby increasing central venous pressure?; An increase in blood volume or venoconstriction. What are the benefits of regular aerobic exercise on the cardiovascular system?; Increased pumping efficiency, blood volume, hemoglobin concentration, number of mitochondria, heart enlargement, increased stroke volume, decreased heart rate and blood pressure. By how much can the heart enlarge due to regular aerobic exercise?; 40% or more. What happens to stroke volume as a result of regular aerobic exercise?; Stroke volume increases. How does regular aerobic exercise affect heart rate and blood pressure?; Heart rate and blood pressure decrease. What percentage of maximum heart rate should be achieved for exercise to benefit the cardiovascular system?; 70 to 85% of maximum (220 - your age). How long should each exercise session last to benefit the cardiovascular system?; 30 to 60 minutes. How often should one exercise per week to benefit the cardiovascular system?; At least 3 to 4 times per week. What are the two pathways formed by blood vessels?; The pulmonary circuit and the systemic circuit. What is the function of the pulmonary circuit?; The pulmonary circuit carries blood between the heart and the lungs. What is the function of the systemic circuit?; The systemic circuit carries blood between the heart and the rest of the body. Which circuit involves the exchange of gases in the lungs?; The pulmonary circuit. Which circuit supplies oxygenated blood to the body's tissues?; The systemic circuit. What is the pathway of blood in the pulmonary circuit?; Right ventricle → pulmonary trunk → right and left pulmonary arteries → lobar branches, repeated divisions → pulmonary arterioles → pulmonary capillaries → pulmonary venules and veins → left atrium. What is the oxygen and carbon dioxide content of blood in the pulmonary arteries and arterioles?; Blood in pulmonary arteries and arterioles is low in O2 and high in CO2. Where does gas exchange occur in the pulmonary circuit?; Gas exchange occurs in pulmonary (alveolar) capillaries. What is the oxygen and carbon dioxide content of blood in the pulmonary venules and veins?; Blood in pulmonary venules and veins is rich in O2 and low in CO2. What is the pathway of blood in the systemic circuit?; Left ventricle → aorta → all arteries and arterioles leading to body tissues → systemic capillaries → systemic venules and veins → right atrium. Where does oxygen-rich blood move from and to in the systemic circuit?; Oxygen-rich blood moves from left atrium to left ventricle. What happens when the left ventricle contracts in the systemic circuit?; Contraction of left ventricle sends blood into systemic circuit. What is the effect of high osmotic pressure in interstitial fluid on alveoli?; It draws water out of the alveoli. What contributes to the osmotic pressure of the interstitial fluid?; Solutes that fail to enter the alveoli. Where does fluid from the interstitial space enter?; Lymphatic capillary or alveolar (blood) capillary. What happens to any excess water in the alveoli?; It is drawn out by the higher osmotic pressure of the interstitial fluid. What is the role of the pulmonary capillary in the alveolar wall?; It allows slight net outflow of fluid. What is the largest artery in the body?; The aorta. What does the aorta supply blood to?; All of the systemic arteries. What are the branches of the ascending aorta?; Right and left coronary arteries. What organ is supplied by the right and left coronary arteries?; Heart. What are the branches of the arch of the aorta?; Brachiocephalic trunk, left common carotid artery, and left subclavian artery. Which regions are supplied by the brachiocephalic trunk?; Right upper limb and right side of the head. Which region is supplied by the left common carotid artery?; Left side of the head. Which region is supplied by the left subclavian artery?; Left upper limb. What are the branches of the abdominal aorta?; Celiac artery, superior mesenteric artery, suprarenal artery, renal artery, gonadal artery, inferior mesenteric artery, lumbar artery, middle sacral artery, and common iliac artery. Which organs are supplied by the celiac artery?; Organs of the upper digestive tract. Which region is supplied by the phrenic artery?; Diaphragm. Which organs are supplied by the superior mesenteric artery?; Portions of the small and large intestines. Which organ is supplied by the suprarenal artery?; Adrenal gland. Which organ is supplied by the renal artery?; Kidney. Which organs are supplied by the gonadal artery?; Ovary or testis. Which region is supplied by the inferior mesenteric artery?; Lower portions of the large intestine. Which region is supplied by the lumbar artery?; Posterior abdominal wall. Which regions are supplied by the middle sacral artery?; Sacrum and coccyx. Which regions are supplied by the common iliac artery?; Lower abdominal wall, pelvic organs, and lower limb. What are the branches of the thoracic aorta?; Bronchial artery, pericardial artery, esophageal artery, mediastinal artery, and posterior intercostal artery. Which region is supplied by the bronchial artery?; Bronchi. Which region is supplied by the pericardial artery?; Pericardium. Which region is supplied by the esophageal artery?; Esophagus. Which region is supplied by the mediastinal artery?; Mediastinum. Which region is supplied by the posterior intercostal artery?; Thoracic wall. What is the name of the vessel labeled as 'Right common carotid a.'?; Right common carotid artery. What is the name of the vessel labeled as 'Right internal jugular v.'?; Right internal jugular vein. What is the name of the vessel labeled as 'Right subclavian a.'?; Right subclavian artery. What is the name of the vessel labeled as 'Brachiocephalic trunk'?; Brachiocephalic trunk. What is the name of the vessel labeled as 'Right subclavian v.'?; Right subclavian vein. What is the name of the vessel labeled as 'Brachiocephalic v.'?; Brachiocephalic vein. What is the name of the vessel labeled as 'Superior vena cava'?; Superior vena cava. What is the name of the vessel labeled as 'Right pulmonary a.'?; Right pulmonary artery. What is the name of the vessel labeled as 'Right pulmonary vv.'?; Right pulmonary veins. What is the name of the structure labeled as 'Right auricle'?; Right auricle. What is the name of the vessel labeled as 'Left common carotid a.'?; Left common carotid artery. What is the name of the vessel labeled as 'Left internal jugular v.'?; Left internal jugular vein. What is the name of the vessel labeled as 'Left subclavian a.'?; Left subclavian artery. What is the name of the vessel labeled as 'Left subclavian v.'?; Left subclavian vein. What is the name of the structure labeled as 'Aortic arch'?; Aortic arch. What is the name of the structure labeled as 'Ligamentum arteriosum'?; Ligamentum arteriosum. What is the name of the vessel labeled as 'Left pulmonary a.'?; Left pulmonary artery. What is the name of the vessel labeled as 'Left pulmonary vv.'?; Left pulmonary veins. What is the name of the structure labeled as 'Left auricle'?; Left auricle. What is the name of the vessel labeled as 'Pulmonary trunk'?; Pulmonary trunk. What is the main artery shown in Figure 15.42?; The abdominal aorta. Which artery branches off to supply the liver?; The hepatic artery. Which artery supplies blood to the spleen?; The splenic artery. What are the major branches of the abdominal aorta shown in the figure?; Celiac artery, hepatic artery, splenic artery, renal artery, superior mesenteric artery, inferior mesenteric artery, and common iliac arteries. Which artery supplies blood to the kidneys?; The renal artery. Which arteries branch off from the superior mesenteric artery?; Intestinal branches. Which arteries branch off from the inferior mesenteric artery?; Branches to the lower part of the large intestine. Which arteries are located at the end of the abdominal aorta?; The common iliac arteries. Which arteries supply blood to the brain, head, and neck?; Branches of the subclavian and common carotid arteries. What is the function of the subclavian arteries?; To supply blood to the brain, head, and neck. What is the function of the common carotid arteries?; To supply blood to the brain, head, and neck. Which artery branches into the internal and external carotid arteries?; The common carotid artery. What does the internal carotid artery supply?; The brain. What does the external carotid artery supply?; The face and neck. Which artery is labeled as 'a' in the diagram?; The internal carotid artery. Which artery is labeled as 'b' in the diagram?; The external carotid artery. Which artery is labeled as 'c' in the diagram?; The vertebral artery. Which artery is labeled as 'd' in the diagram?; The subclavian artery. What is the cerebral arterial circle also known as?; The circle of Willis. Which artery systems does the cerebral arterial circle join?; The carotid and vertebral artery systems. What is the function of the cerebral arterial circle?; It supplies blood to the brain and provides alternate pathways for blood to reach the brain. From where do the cerebral arteries emerge to supply blood to brain tissues?; From the cerebral arterial circle (circle of Willis). What artery gives off branches in the neck and continues into the arm?; The subclavian artery. What is the name of the artery that continues from the subclavian artery into the arm?; The axillary artery. Which artery is located in the upper arm and is a continuation of the axillary artery?; The brachial artery. What are the two main branches of the brachial artery in the forearm?; The radial artery and the ulnar artery. Which artery supplies blood to the thumb?; The principal artery of the thumb. What is the name of the artery that supplies blood to the deep structures of the arm?; The deep brachial artery. Which arteries form the palmar arches in the hand?; The deep palmar arch and the superficial palmar arch. What are the names of the arteries that supply blood to the fingers?; The digital arteries. Which artery is responsible for the blood supply to the posterior humeral circumflex region?; The posterior humeral circumflex artery. Which artery is responsible for the blood supply to the anterior humeral circumflex region?; The anterior humeral circumflex artery. Which arteries supply blood to the thoracic wall?; Branches of the subclavian artery and the thoracic aorta. What is the role of the subclavian artery in the thoracic wall?; It supplies blood to the thoracic wall. What is the role of the thoracic aorta in the thoracic wall?; It supplies blood to the thoracic wall. Which arteries are labeled in the diagram of the thoracic and abdominal walls?; Posterior intercostal a., Internal intercostal m., Internal thoracic a., External intercostal m., Anterior intercostal aa. What structures are shown in the diagram of the thoracic and abdominal walls?; Vertebral body, Thoracic aorta, Sternum, Costal cartilage. Into which arteries does the abdominal aorta divide?; The common iliac arteries. What regions do the common iliac arteries supply blood to?; The pelvic organs, gluteal region, and lower limbs. Into which arteries does the common iliac artery divide?; The internal iliac artery and external iliac artery. Which artery supplies blood to the pelvic and gluteal areas?; The internal iliac artery. What arteries provide the major blood supply to the lower limbs?; The external iliac arteries. Where are the external iliac arteries located?; They are located in the lower abdomen and pelvis, extending into the lower limbs. What is the function of the external iliac arteries?; To provide the major blood supply to the lower limbs. What is the main function of the venous system?; To return deoxygenated blood back to the heart. What major vein returns blood from the upper body to the heart?; Superior vena cava. What major vein returns blood from the lower body to the heart?; Inferior vena cava. Which vein is responsible for draining blood from the brain?; Internal jugular vein. Which vein is responsible for draining blood from the arms?; Subclavian vein. What is the name of the vein that drains blood from the liver?; Hepatic vein. Which vein drains blood from the kidneys?; Renal vein. What is the name of the vein that drains blood from the legs?; Femoral vein. Which vein is located in the lower leg and drains blood from the foot?; Anterior tibial vein. What is the function of the external jugular vein?; To drain blood from the face and neck. What does systemic venous circulation do?; Returns blood to the heart after exchange of gases, nutrients, and wastes between blood and cells. How do vessels of the venous system originate?; From the merging of capillaries into venules, venules into small veins, and small veins into larger ones. Why are venous pathways difficult to follow compared to arterial pathways?; Due to irregular networks and unnamed tributaries. What do pathways of larger veins usually parallel?; Arteries of the same name. Into which veins do all systemic veins converge?; Superior and inferior venae cavae. Through which part of the heart do the superior and inferior venae cavae return blood?; The right atrium. What do the external jugular veins drain blood from?; The face, scalp, and superficial neck. What do the internal jugular veins drain blood from?; The brain, and deep portions of the face and neck. What are the two systems of veins that drain the upper limb and shoulder?; Deep set of veins and superficial set of veins. What is the pathway of the deep set of veins in the upper limb?; Digital veins → radial and ulnar veins → brachial veins. What is the pathway of the superficial set of veins in the upper limb?; Anastomoses in palm and wrist → basilic and cephalic veins. Which veins do the basilic and cephalic veins join?; Basilic vein joins brachial vein, and cephalic vein joins axillary vein. Which veins do the digital veins drain into in the deep set of veins?; Radial and ulnar veins. Which veins do the radial and ulnar veins drain into in the deep set of veins?; Brachial veins. Where do the anastomoses in the superficial set of veins occur?; In the palm and wrist. Which vein does the basilic vein join?; Brachial vein. Which vein does the cephalic vein join?; Axillary vein. Which veins drain the abdominal and thoracic walls?; Tributaries of the brachiocephalic and azygos veins. Into which vein does the azygos vein drain directly?; The superior vena cava. What is the role of the azygos vein?; It drains the abdominal and thoracic walls and empties into the superior vena cava. What are the main tributaries of the brachiocephalic veins?; Veins from the abdominal and thoracic walls. What is unusual about portal veins?; They do not transport blood directly to the heart. What unique venous pathway drains the abdominal viscera?; The hepatic portal system. Which organs' capillaries drain into the hepatic portal vein?; Stomach, intestines, pancreas, and spleen. Where does the hepatic portal vein transport blood for processing?; To the liver. After processing in the liver, where is the blood delivered?; To the inferior vena cava. What is a portal system?; A system that filters blood through 2 sets of capillaries instead of the usual 1 set. Name two examples of portal systems in the human body.; Hepatic Portal System and Renal Portal System. What unique function does the second set of capillaries in a portal system perform?; It performs a unique function in the body by filtering blood through an additional set of capillaries. What is the primary function of the Hepatic Portal System?; To filter blood from the gastrointestinal tract and spleen through the liver. What is the primary function of the Renal Portal System?; To filter blood through the kidneys. Into which groups do veins from the lower limb drain?; Deep and superficial groups of veins. What is the sequence of veins in the deep set from the foot to the external iliac vein?; Veins in foot → anterior and posterior tibial veins → popliteal vein → femoral vein → external iliac vein. What is the sequence of veins in the superficial set from the foot?; Veins in foot → small and great saphenous veins. Which vein is the longest in the body?; The great saphenous vein. Which veins in the foot drain into the anterior and posterior tibial veins?; Veins in the foot. Into which vein do the anterior and posterior tibial veins drain?; The popliteal vein. Into which vein does the popliteal vein drain?; The femoral vein. Into which vein does the femoral vein drain?; The external iliac vein. Which veins in the foot drain into the small and great saphenous veins?; Veins in the foot. What happens to cholesterol in the blood vessels as people age?; Cholesterol deposition in the blood vessels increases. What happens to coronary arteries with age?; Coronary arteries become narrowed. How can the heart change in size due to disease?; The heart may shrink slightly or enlarge due to disease. What happens to the proportion of the heart consisting of cardiac muscle as people age?; The proportion of the heart consisting of cardiac muscle declines. What type of tissue increases in the heart with age?; Fibrous connective tissue increases in the heart. What happens to the adipose tissue in the heart as people age?; Adipose tissue in the heart increases. Which parts of the heart may thicken with age?; Heart valves and the left ventricular wall may thicken. What happens to systolic blood pressure as people age?; Systolic blood pressure increases. What happens to the resting heart rate with age?; The resting heart rate decreases. What happens to the lumens of large arteries as people age?; The lumens of large arteries narrow as arterial walls thicken. What happens to arterial elasticity with age?; Arterial elasticity decreases. What factors contribute to cardiovascular disease?; Both environmental and hereditary factors. What is Marfan syndrome?; A connective tissue defect involving an abnormal type of the protein fibrillin, which can weaken the wall of the aorta and result in its bursting and sudden death. What protein is abnormal in Marfan syndrome?; Fibrillin. What is Familial hypertrophic cardiomyopathy?; An inherited overgrowth of myocardium caused by an abnormal myosin chain in cardiac muscle, which can result in sudden death. What defect causes Familial hypertrophic cardiomyopathy?; A myosin defect. What is the result of an inherited deficiency of a mitochondrial enzyme that breaks down fatty acids?; Heart failure due to the inability to break down long-chain fatty acids and use them for energy. What is the primary energy source for cardiac muscle?; Long-chain fatty acids. What is Familial hypercholesterolemia?; A condition where abnormal LDL receptors on liver cells do not take up cholesterol from the blood, resulting in high cholesterol and coronary artery disease. What is the consequence of abnormal LDL receptors in Familial hypercholesterolemia?; High cholesterol and coronary artery disease. What is Coronary Artery Disease (CAD)?; A disease involving deposition of cholesterol plaque on inner walls of coronary arteries. What does Coronary Artery Disease lead to?; Obstruction of coronary arteries and O2 deficiency in cardiac muscle. What conditions often accompany Coronary Artery Disease?; High serum cholesterol and hypertension. What is the term for chest pain caused by exertion in Coronary Artery Disease?; Angina pectoris. What major health event is Coronary Artery Disease a contributing factor to?; Myocardial infarction (heart attack). What are two treatments for Coronary Artery Disease?; Percutaneous transluminal coronary angioplasty (PTCA) and coronary bypass surgery. Where is the aortic valve best heard?; In the second intercostal space right of the sternum. Where is the pulmonary valve best heard?; In the second intercostal space left of the sternum. Where is the tricuspid valve best heard?; At the fifth intercostal space left of the sternum. Where is the mitral valve best heard?; In the fifth intercostal space on the left at the nipple line. Where can the pulse of the temporal artery be taken?; Anterior to the ear. Where is the pulse of the carotid artery measured?; In the inferior medial portion of the neck. Where can the pulse of the brachial artery be taken?; In the distal brachial region on the anterior side. Where is the pulse of the radial artery measured?; On the lateral side of the wrist on the anterior side. Where can the pulse of the femoral artery be taken?; In the inguinal region. Where is the pulse of the popliteal artery measured?; In the popliteal region. Where can the pulse of the dorsalis pedis artery be taken?; In the anterior ankle. Where is the pulse of the posterior tibia artery measured?; In the posterior ankle. What are the functions of the organs of the cardiovascular system?; The organs of the cardiovascular system function to transport nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes (carbon dioxide, nitrogenous wastes). What are the coverings of the heart?; The coverings of the heart include the pericardium, which consists of the fibrous pericardium and the serous pericardium. What are the layers that compose the wall of the heart?; The layers that compose the wall of the heart are the epicardium, myocardium, and endocardium. What are the major parts of the heart?; The major parts of the heart include the atria, ventricles, valves (tricuspid, pulmonary, mitral, and aortic), and septum. What is the function of the atria in the heart?; The atria receive blood returning to the heart from the body and lungs. What is the function of the ventricles in the heart?; The ventricles pump blood out of the heart to the lungs and the rest of the body. What is the function of the heart valves?; The heart valves ensure unidirectional blood flow through the heart. What is the pathway of blood through the heart?; Blood flows from the right atrium to the right ventricle, then to the lungs via the pulmonary arteries, returns to the left atrium via the pulmonary veins, and then to the left ventricle, which pumps it out to the body through the aorta. What is coronary circulation?; Coronary circulation is the circulation of blood in the blood vessels of the heart muscle (myocardium). What is the cardiac cycle?; The cardiac cycle is the sequence of events in one heartbeat, including systole (contraction) and diastole (relaxation) of the atria and ventricles. How are heart sounds produced?; Heart sounds are produced by the closing of the heart valves; the 'lub' sound is caused by the closure of the AV valves, and the 'dub' sound is caused by the closure of the semilunar valves. What are the parts of a normal ECG pattern?; The parts of a normal ECG pattern include the P wave, QRS complex, and T wave. What is the significance of the P wave in an ECG pattern?; The P wave represents atrial depolarization. What does the QRS complex in an ECG pattern signify?; The QRS complex represents ventricular depolarization. What does the T wave in an ECG pattern indicate?; The T wave represents ventricular repolarization. How is the cardiac cycle controlled?; The cardiac cycle is controlled by the sinoatrial (SA) node, atrioventricular (AV) node, and the conduction system of the heart. What are the major types of blood vessels?; The major types of blood vessels are arteries, veins, and capillaries. How do the structures of arteries and veins differ?; Arteries have thicker walls and more elastic tissue compared to veins, which have thinner walls and valves to prevent backflow. What is the primary function of capillaries?; The primary function of capillaries is to facilitate the exchange of substances between blood and tissue fluid. How are substances exchanged between blood in capillaries and tissue fluid?; Substances are exchanged between blood in capillaries and tissue fluid through diffusion, filtration, and osmosis. How is blood pressure produced?; Blood pressure is produced by the force of the heart pumping blood and the resistance of blood vessels. What mechanisms aid in returning venous blood to the heart?; Mechanisms that aid in returning venous blood to the heart include the skeletal muscle pump, respiratory pump, and venous valves. What are the two circuits of the cardiovascular system?; The pulmonary and systemic circuits. What is the function of the pulmonary circuit?; The pulmonary circuit carries blood between the heart and the lungs. What is the function of the systemic circuit?; The systemic circuit carries blood between the heart and the rest of the body. What are the major components of the arterial system?; The major arteries. What are the major components of the venous system?; The major veins. What changes occur in the cardiovascular system over a lifespan?; Various structural and functional changes.