angio-: vessel
angiotensināsubstance that constricts blood vessels.
ather-: porridge
atherosclerosisādeposits of plaque in arteries.
brady-: slow
bradycardiaāabnormally slow heartbeat.
diastol-: dilation
diastolic pressureāblood pressure when the ventricle of the heart is relaxed.
edem-: swelling
edemaāaccumulation of fluids in the tissues that causes them to swell.
-gram: something written
electrocardiogramārecording of the electrical changes in the myocardium during a cardiac cycle.
lun-: moon
semilunar valveāvalve with crescent-shaped flaps.
myo-: muscle
myocardiumāmuscle tissue within the wall of the heart.
papill-: nipple
papillary muscleāsmall mound of muscle projecting into a ventricle of the heart.
phleb-: vein
phlebitisāinflammation of a vein.
scler-: hard
arteriosclerosisāloss of elasticity and hardening of a blood vessel wall.
syn-: together
syncytiumāmass of merging cells that act together.
systol-: contraction
systolic pressureāblood pressure resulting from a single-ventricular contraction.
tachy-: rapid
tachycardiaāabnormally fast heartbeat.
Ā©2019 McGraw-Hill Education.
The heart pumps 7,000 liters of blood through the body each day.
The heart contracts 2.5 billion times during an average lifetime.
Blood travels through the blood vessels in this sequence:
arteries ā arterioles ā capillaries ā venules ā veins ā back to heart.
The cardiovascular system comprises the heart and all blood vessels.
Cardiovascular refers to both the heart and blood vessels.
The heart's pumping action circulates blood through blood vessels.
Blood vessels form two circuits:
Pulmonary Circuit:
Transports oxygen-poor blood from the heart to the lungs and back to the heart.
In the lungs, blood picks up Oā and drops off COā.
Systemic Circuit:
Transports oxygen-rich blood from the heart to body cells and back to the heart.
Blood delivers nutrients to cells and removes wastes.
The heart is a hollow, cone-shaped, muscular pump.
Located in the mediastinum of the thoracic cavity, above the diaphragm.
Structure:
4 chambers:
2 atria (upper chambers)
2 ventricles (lower chambers for pumping action)
14 cm long and 9 cm wide.
Positioned:
Posterior to the sternum
Medial to the lungs
Anterior to the vertebral column
Base lies beneath the 2nd rib
Apex lies at the 5th intercostal space
Coverings of the Heart:
Pericardium:
Fibrous pericardium: Outer layer enclosing double-layered serous membrane.
Parietal pericardium: Deep to fibrous, outer serous membrane.
Visceral pericardium (epicardium): Inner serous layer, attached to the heartās surface.
The heart wall has 3 layers:
Epicardium:
Outer layer also called the visceral pericardium.
Thin serous membrane.
Myocardium:
Middle layer made of cardiac muscle tissue.
Thickest layer, responsible for contraction.
Endocardium:
Inner layer lining all heart chambers.
Thin, endothelial layer.
Layer | Composition | Function |
---|---|---|
Epicardium | Serous membrane (connective tissue + epithelium) | Protective outer cover, secretes serous fluid |
Myocardium | Cardiac muscle tissue | Contracts to pump blood |
Endocardium | Membrane of epithelium and connective tissue | Forms protective inner heart lining |
Chambers:
Atria: Upper, thin-walled chambers receiving blood.
Ventricles: Lower, thick-walled chambers pumping blood into arteries.
Right Atrium:
Receives systemic circuit blood (from the superior and inferior vena cavae and coronary sinus).
Pumps blood to the right ventricle.
Right Ventricle:
Receives blood from the right atrium.
Pumps blood to the lungs.
Left Atrium:
Receives blood from pulmonary veins.
Pumps blood to left ventricle.
Left Ventricle:
Receives blood from the left atrium.
Pumps blood to systemic circuit.
Valve | Location | Function |
---|---|---|
Tricuspid Valve | Right atrioventricular orifice | Prevents backflow from right ventricle to right atrium |
Pulmonary Valve | Entrance to the pulmonary trunk | Prevents backflow from pulmonary trunk to right ventricle |
Mitral Valve | Left atrioventricular orifice | Prevents backflow from left ventricle to left atrium |
Aortic Valve | Entrance to aorta | Prevents backflow from aorta to left ventricle |
The heart's rhythmic contraction and relaxation represent a cardiac cycle.
Coordinated function of heart chambers.
Atrial systole (atria contract) and ventricular diastole (ventricles relax), followed by ventricular systole (ventricles contract) and atrial diastole (atria relax).
āLubbā: First heart sound, during ventricular systole, caused by AV valves closing.
āDuppā: Second heart sound, during ventricular diastole, caused by pulmonary and aortic semilunar valves closing.
Murmur: Abnormal sound from incomplete valve closure.
Components:
SA Node (Sinoatrial Node): Pacemaker, initiates heart contractions.
Internodal Atrial Muscle: Carries impulses from SA node to atria.
Junctional Fibers: Transmit impulses from SA node to AV node.
AV Node (Atrioventricular Node): Delays impulses before passing to AV Bundle.
AV Bundle (Bundle of His): Transmits impulses quickly to bundle branches.
Left and Right Bundle Branches: Carry impulses to Purkinje fibers.
Purkinje Fibers: Conduct impulses to ventricular myocardium, causing contraction.
Recording electrical changes in the myocardium during the cardiac cycle.
ECG Waves:
P Wave: Atrial depolarization (just before atrial contraction).
QRS Complex: Ventricular depolarization (just before ventricular contraction).
T Wave: Ventricular repolarization (just before ventricular relaxation).
The SA node modulates heart rate.
The autonomic nervous system influences the heart rate through sympathetic and parasympathetic fibers.
Factors affecting heart rate include physical exercise, body temperature, and concentrations of ions (like Kāŗ and CaĀ²āŗ).
Types:
Fibrillation: Uncoordinated contractions.
Tachycardia: Fast heartbeat (>100 beats/min at rest).
Bradycardia: Slow heartbeat (<60 beats/min at rest).
Flutter: Rapid, regular contractions (250-350 beats/min).
Regular aerobic exercise enhances cardiovascular efficiency.
Benefits include increased blood volume, hemoglobin concentration, and cardiac muscle size.
Recommendations:
Heart rate at 70-85% of max rate.
Duration: 30 to 60 minutes, 3 to 4 times a week.
Types:
Arteries and Arterioles: Carry blood away from the heart.
Capillaries: Sites of substance exchange between blood and body cells.
Venules and Veins: Transport blood back to the heart
angio-: vessel
angiotensināsubstance that constricts blood vessels.
ather-: porridge
atherosclerosisādeposits of plaque in arteries.
brady-: slow
bradycardiaāabnormally slow heartbeat.
diastol-: dilation
diastolic pressureāblood pressure when the ventricle of the heart is relaxed.
edem-: swelling
edemaāaccumulation of fluids in the tissues that causes them to swell.
-gram: something written
electrocardiogramārecording of the electrical changes in the myocardium during a cardiac cycle.
lun-: moon
semilunar valveāvalve with crescent-shaped flaps.
myo-: muscle
myocardiumāmuscle tissue within the wall of the heart.
papill-: nipple
papillary muscleāsmall mound of muscle projecting into a ventricle of the heart.
phleb-: vein
phlebitisāinflammation of a vein.
scler-: hard
arteriosclerosisāloss of elasticity and hardening of a blood vessel wall.
syn-: together
syncytiumāmass of merging cells that act together.
systol-: contraction
systolic pressureāblood pressure resulting from a single-ventricular contraction.
tachy-: rapid
tachycardiaāabnormally fast heartbeat.
Ā©2019 McGraw-Hill Education.
The heart pumps 7,000 liters of blood through the body each day.
The heart contracts 2.5 billion times during an average lifetime.
Blood travels through the blood vessels in this sequence:
arteries ā arterioles ā capillaries ā venules ā veins ā back to heart.
The cardiovascular system comprises the heart and all blood vessels.
Cardiovascular refers to both the heart and blood vessels.
The heart's pumping action circulates blood through blood vessels.
Blood vessels form two circuits:
Pulmonary Circuit:
Transports oxygen-poor blood from the heart to the lungs and back to the heart.
In the lungs, blood picks up Oā and drops off COā.
Systemic Circuit:
Transports oxygen-rich blood from the heart to body cells and back to the heart.
Blood delivers nutrients to cells and removes wastes.
The heart is a hollow, cone-shaped, muscular pump.
Located in the mediastinum of the thoracic cavity, above the diaphragm.
Structure:
4 chambers:
2 atria (upper chambers)
2 ventricles (lower chambers for pumping action)
14 cm long and 9 cm wide.
Positioned:
Posterior to the sternum
Medial to the lungs
Anterior to the vertebral column
Base lies beneath the 2nd rib
Apex lies at the 5th intercostal space
Coverings of the Heart:
Pericardium:
Fibrous pericardium: Outer layer enclosing double-layered serous membrane.
Parietal pericardium: Deep to fibrous, outer serous membrane.
Visceral pericardium (epicardium): Inner serous layer, attached to the heartās surface.
The heart wall has 3 layers:
Epicardium:
Outer layer also called the visceral pericardium.
Thin serous membrane.
Myocardium:
Middle layer made of cardiac muscle tissue.
Thickest layer, responsible for contraction.
Endocardium:
Inner layer lining all heart chambers.
Thin, endothelial layer.
Layer | Composition | Function |
---|---|---|
Epicardium | Serous membrane (connective tissue + epithelium) | Protective outer cover, secretes serous fluid |
Myocardium | Cardiac muscle tissue | Contracts to pump blood |
Endocardium | Membrane of epithelium and connective tissue | Forms protective inner heart lining |
Chambers:
Atria: Upper, thin-walled chambers receiving blood.
Ventricles: Lower, thick-walled chambers pumping blood into arteries.
Right Atrium:
Receives systemic circuit blood (from the superior and inferior vena cavae and coronary sinus).
Pumps blood to the right ventricle.
Right Ventricle:
Receives blood from the right atrium.
Pumps blood to the lungs.
Left Atrium:
Receives blood from pulmonary veins.
Pumps blood to left ventricle.
Left Ventricle:
Receives blood from the left atrium.
Pumps blood to systemic circuit.
Valve | Location | Function |
---|---|---|
Tricuspid Valve | Right atrioventricular orifice | Prevents backflow from right ventricle to right atrium |
Pulmonary Valve | Entrance to the pulmonary trunk | Prevents backflow from pulmonary trunk to right ventricle |
Mitral Valve | Left atrioventricular orifice | Prevents backflow from left ventricle to left atrium |
Aortic Valve | Entrance to aorta | Prevents backflow from aorta to left ventricle |
The heart's rhythmic contraction and relaxation represent a cardiac cycle.
Coordinated function of heart chambers.
Atrial systole (atria contract) and ventricular diastole (ventricles relax), followed by ventricular systole (ventricles contract) and atrial diastole (atria relax).
āLubbā: First heart sound, during ventricular systole, caused by AV valves closing.
āDuppā: Second heart sound, during ventricular diastole, caused by pulmonary and aortic semilunar valves closing.
Murmur: Abnormal sound from incomplete valve closure.
Components:
SA Node (Sinoatrial Node): Pacemaker, initiates heart contractions.
Internodal Atrial Muscle: Carries impulses from SA node to atria.
Junctional Fibers: Transmit impulses from SA node to AV node.
AV Node (Atrioventricular Node): Delays impulses before passing to AV Bundle.
AV Bundle (Bundle of His): Transmits impulses quickly to bundle branches.
Left and Right Bundle Branches: Carry impulses to Purkinje fibers.
Purkinje Fibers: Conduct impulses to ventricular myocardium, causing contraction.
Recording electrical changes in the myocardium during the cardiac cycle.
ECG Waves:
P Wave: Atrial depolarization (just before atrial contraction).
QRS Complex: Ventricular depolarization (just before ventricular contraction).
T Wave: Ventricular repolarization (just before ventricular relaxation).
The SA node modulates heart rate.
The autonomic nervous system influences the heart rate through sympathetic and parasympathetic fibers.
Factors affecting heart rate include physical exercise, body temperature, and concentrations of ions (like Kāŗ and CaĀ²āŗ).
Types:
Fibrillation: Uncoordinated contractions.
Tachycardia: Fast heartbeat (>100 beats/min at rest).
Bradycardia: Slow heartbeat (<60 beats/min at rest).
Flutter: Rapid, regular contractions (250-350 beats/min).
Regular aerobic exercise enhances cardiovascular efficiency.
Benefits include increased blood volume, hemoglobin concentration, and cardiac muscle size.
Recommendations:
Heart rate at 70-85% of max rate.
Duration: 30 to 60 minutes, 3 to 4 times a week.
Types:
Arteries and Arterioles: Carry blood away from the heart.
Capillaries: Sites of substance exchange between blood and body cells.
Venules and Veins: Transport blood back to the heart