BIOL 109 Exam 3 Study Guide (Ch 12, 13, 14, 15, 16)

What are the two circuits of the cardiovascular system?

Pulmonary circuit (carries blood to/from lungs) and systemic circuit (carries blood to/from the rest of the body)

Which vessels carry blood away from the heart, and which return blood to the heart?

Arteries carry blood away from the heart; veins return blood to the heart

What are the four chambers of the heart?

Right atrium, right ventricle, left atrium, and left ventricle

What is the pericardium and what are its layers?

The pericardium surrounds the heart; it is lined by the serous pericardium. The visceral layer (epicardium) covers the heart's outer surface

What are the three layers of the heart wall?

Myocardium (muscular bulk), endocardium (lines inner surfaces), and epicardium (covers outer surface)

What connects cardiac muscle cells together and what do they do?

Intercalated discs convey the force of contraction from cell to cell and transmit action potentials

What veins bring blood to the right atrium?

Superior vena cava and inferior vena cava

What valve separates the right atrium from the right ventricle?

Tricuspid valve (right AV valve), bounded by three cusps and chordae tendineae attached to papillary muscles

What valve does blood pass through when leaving the right ventricle?

Pulmonary semilunar valve; blood enters the pulmonary trunk which divides into left and right pulmonary arteries

What valve separates the left atrium from the left ventricle?

Mitral valve (left AV valve or bicuspid valve)

What valve does blood pass through when leaving the left ventricle?

Aortic semilunar valve; blood enters the systemic circuit through the aorta

What is the SA node and what does it do?

Sinoatrial node; it is the cardiac pacemaker that normally establishes the rate of heart contraction

What does the P wave represent on an ECG?

Atrial depolarization

What does the QRS complex represent on an ECG?

Ventricular depolarization

What does the T wave represent on an ECG?

Ventricular repolarization

What is a cardiac cycle?

A sequence of systole (contraction) followed by diastole (relaxation); both ventricles contract simultaneously and eject equal volumes of blood

What causes the first and second heart sounds?

First sound (lub) = AV valves closing; second sound (dub) = semilunar valves closing

What is stroke volume?

The amount of blood ejected by a ventricle during a single beat

What is cardiac output?

The amount of blood pumped by the left ventricle each minute; CO = stroke volume × heart rate

What is the difference between arteries and veins?

Arteries have thicker walls and carry blood away from heart at high pressure; veins have thinner walls, lower pressure, and contain valves to prevent backflow

What are the three classes of lymphocytes?

T cells (cell-mediated immunity), B cells (antibody-mediated/humoral immunity), and NK cells (immune surveillance)

What are antibodies and name the 5 classes?

Proteins produced by B cells that react with antigens. Five classes: IgG, IgM, IgA, IgE, and IgD

What are the parts of the respiratory system?

Upper: nose, nasal cavity, paranasal sinuses, pharynx. Lower: larynx, trachea, bronchi, bronchioles, alveoli

What are the main parts of the digestive tract?

Oral cavity, pharynx, esophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (cecum, colon, rectum), anus

What is the function of the stomach?

Stores and churns food, mixes with gastric secretions (HCl, pepsinogen) to form chyme for chemical and mechanical digestion

What are the three layers of blood vessel walls?

Tunica intima (innermost), tunica media (smooth muscle and elastic fibers), tunica externa (outermost connective tissue)

What is the main function of capillaries?

Allow exchange of solutes and water between blood and interstitial fluid; only blood vessels whose walls permit exchange

What is innate immunity?

Nonspecific defense that protects without distinguishing one threat from another; includes physical barriers, phagocytes, NK cells, interferons, complement system

What is adaptive immunity?

Specific defense provided by T and B cells that responds to particular threats; includes specificity, versatility, memory, and tolerance

What are the structures that increase surface area in the small intestine?

Circular folds and intestinal villi; each villus contains a lacteal (lymphatic capillary)

What are the functions of the pancreas?

Endocrine: secretes insulin and glucagon; exocrine: secretes pancreatic juice with digestive enzymes (amylase, lipase, proteases) and buffers into duodenum

How is oxygen transported in blood?

Most oxygen is bound to hemoglobin in red blood cells (oxyhemoglobin); small amount dissolved in plasma

How is carbon dioxide transported in blood?

7% dissolved in plasma; 23% bound to hemoglobin (carbaminohemoglobin); 70% as bicarbonate ion (HCO3-) via carbonic acid buffering system

What are the main functions of the urinary system?

Excretion (removal of metabolic wastes), elimination (discharge into environment), and homeostatic regulation of blood plasma volume, ions, pH, and nutrients

What is a nephron and what are its main parts?

The basic functional unit of the kidney; consists of renal corpuscle (glomerulus + glomerular capsule) and renal tubule (proximal convoluted tubule, nephron loop, distal convoluted tubule)

What is glomerular filtration?

Blood pressure moves fluids across the wall of glomerular capillaries into the capsular space; produces the filtrate

What happens in the proximal convoluted tubule?

Actively reabsorbs nutrients (glucose, amino acids), ions, and water; reabsorbed substances return to blood

What role does the nephron loop play?

Descending limb is permeable to water, allowing water reabsorption; ascending limb pumps sodium and chloride out without water reabsorption

What role does antidiuretic hormone (ADH) play in the kidney?

ADH makes collecting duct permeable to water, allowing water reabsorption and concentration of urine to maintain blood osmotic pressure

What is the normal pH range of blood and what are acidosis and alkalosis?

Normal pH: 7.35-7.45. Acidosis: pH <7.35 (excess acid/H+). Alkalosis: pH >7.45 (excess base/loss of H+). Maintained by buffers and respiratory/renal compensation

Epicardium (visceral pericardium): covers the outer surface of the heart. Myocardium: thick muscular layer that contracts to pump blood. Endocardium: lines the inner surfaces of the heart chambers

Epicardium (visceral pericardium): covers the outer surface of the heart. Myocardium: thick muscular layer that contracts to pump blood. Endocardium: lines the inner surfaces of the heart chambers

Describe the structure and function of cardiac muscle cells

Branching cells interconnected by intercalated discs that contain desmosome and gap junctions. Desmosomes transmit contractile force; gap junctions allow rapid electrical communication. Contains myofibrils with sarcomeres for contraction

What structural features allow blood flow from right atrium to right ventricle?

Tricuspid valve (right AV valve) with three cusps. Cusps attached to papillary muscles via chordae tendineae which prevent valve leaflets from everting during RV contraction

Explain the blood flow pathway through the entire heart

Deoxygenated blood enters right atrium from superior and inferior vena cava → right ventricle via tricuspid valve → pulmonary trunk (through pulmonary semilunar valve) → divides into left and right pulmonary arteries → lungs. Oxygenated blood returns via pulmonary veins to left atrium → left ventricle via mitral valve → exits through aortic semilunar valve into aorta for systemic circulation

What are the functions of the lymphatic system in relation to the cardiovascular system?

Return excess tissue fluid (lymph) to the blood. Involved in immune function. Lymphatic vessels absorb fluid from interstitial spaces and return it to the bloodstream via the thoracic duct and right lymphatic duct

What is the renin-angiotensin-aldosterone system (RAAS) and how does it regulate blood pressure?

Hormone system activated when blood pressure drops or sodium levels are low. Kidneys release renin, which triggers production of angiotensin II. Angiotensin II causes vasoconstriction (raises BP) and stimulates aldosterone release to increase sodium reabsorption and blood volume