What is the general function of the cardiovascular system?
The cardiovascular system (heart + blood vessels) transports blood throughout the body to provide adequate perfusion, meaning sufficient delivery of blood per time per gram of tissue (mL/min/g) to maintain cell health. It requires continual pumping of the heart and open, healthy vessels.
What is perfusion?
Perfusion is the delivery of blood per time per gram of tissue (mL/min/g). Adequate perfusion is necessary to maintain cellular health.
What are the three types of blood vessels and their functions?
Arteries carry blood away from the heart (most carry oxygenated blood). Veins carry blood back to the heart (most carry deoxygenated blood). Capillaries are sites of gas exchange between blood and air in lungs and between blood and body cells.
Describe the right side of the heart.
The right side receives deoxygenated blood from the body and pumps it to the lungs via pulmonary circulation.
Describe the left side of the heart.
The left side receives oxygenated blood from the lungs and pumps it to systemic tissues via systemic circulation.
What are the four chambers of the heart?
Two atria (superior chambers that receive blood and send it to ventricles) and two ventricles (inferior chambers that pump blood away from the heart).
What are the great vessels of the heart and their functions?
Superior and inferior vena cava: drain deoxygenated blood into right atrium. Pulmonary trunk: carries blood from right ventricle and splits into pulmonary arteries. Pulmonary veins: return oxygenated blood to left atrium. Aorta: transports blood from left ventricle to systemic circulation.
What are the two types of heart valves and their locations?
Atrioventricular (AV) valves: between atria and ventricles (Right = tricuspid, Left = bicuspid/mitral). Semilunar valves: pulmonary semilunar (between right ventricle and pulmonary trunk), aortic semilunar (between left ventricle and aorta).
Describe pulmonary circulation.
Right heart → lungs → left heart. Deoxygenated blood travels to lungs, releases CO₂, picks up O₂, and returns oxygenated to left heart.
Describe systemic circulation.
Left heart → systemic tissues → right heart. Oxygenated blood delivers O₂ and nutrients to cells, picks up wastes, and returns deoxygenated blood to right heart.
What is congestive heart failure?
Impaired ability of the heart to pump blood effectively, leading to edema (fluid accumulation).
What causes systemic edema in heart failure?
Right ventricle impairment causes blood to back up in systemic circulation, increasing fluid in interstitial spaces.
What causes pulmonary edema in heart failure?
Left ventricle impairment causes blood to back up in pulmonary circulation, leading to fluid accumulation in lungs and breathing difficulties.
Where is the heart located?
In the thoracic cavity within the mediastinum, posterior to the sternum and slightly left of midline, enclosed in the pericardium.
What is the base and apex of the heart?
Base: wide superior surface where large vessels attach. Apex: tapered inferior end.
Describe the pericardium.
A double-walled sac enclosing the heart. Fibrous pericardium: dense irregular CT, anchors heart and prevents overfilling. Serous pericardium: parietal layer (attaches to fibrous pericardium) and visceral layer (epicardium; attaches to heart). Pericardial cavity: space between parietal and visceral layers.
What is pericarditis?
Inflammation of the pericardium caused by infection (viral, bacterial, fungal), leading to fluid accumulation and possibly cardiac tamponade (compression preventing proper filling). Produces friction rub sound.
What are the three layers of the heart wall?
Epicardium (outermost; visceral pericardium), myocardium (thick middle cardiac muscle layer), endocardium (inner lining covering chambers and valves).
Why is the left ventricle thicker than the right?
It must generate greater pressure to pump blood throughout systemic circulation, which is farther and higher resistance than pulmonary circulation.
What causes normal heart sounds S1 and S2?
S1 (“lubb”): closing of AV valves. S2 (“dupp”): closing of semilunar valves.
What is a heart murmur?
An abnormal heart sound due to turbulent blood flow, often caused by valvular stenosis or insufficiency.
What is valvular stenosis?
Valve cusps scar and cannot open fully, increasing resistance and reducing chamber output.
What is valvular insufficiency?
Valve cusps do not close tightly, causing regurgitation (backflow) and possible heart enlargement.
What does it mean that the heart is myogenic and autorhythmic?
Myogenic: signal originates within the heart itself. Autorhythmic: heart generates its own rhythm without nervous system input.
