Circulation and Cardiac Physiology

The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs for oxygenation.

Blood becomes oxygen-rich after it travels through the lungs, where it unloads carbon dioxide and picks up oxygen.

The right ventricle has a short, low-pressure workload while the left ventricle has a long pathway with high pressure and more resistance.

<p>The coronary arteries supply the heart muscle (myocardium) with blood, delivering necessary nutrients and oxygen.</p> Signup and view all the answers

<p>During ventricular contraction, the myocardium compresses the coronary arteries, restricting blood flow to the heart muscle.</p> Signup and view all the answers

<p>At rest, myocardial cells have a high concentration of K+ inside and a low concentration of Na+, which is vital for maintaining the resting membrane potential.</p> Signup and view all the answers

<p>The pulmonary circuit carries deoxygenated blood to the lungs, while the systemic circuit distributes oxygen-rich blood to the body.</p> Signup and view all the answers

<p>Cardiac action potentials facilitate the electrical impulses that trigger myocardial contractions and the cardiac cycle.</p> Signup and view all the answers

<p>The movement of K+ out of the cell contributes to a loss of positive charge, maintaining a negative resting membrane potential of -80 to -90 mV.</p> Signup and view all the answers

<p>When the membrane potential reaches the threshold, an action potential is generated, leading to depolarization.</p> Signup and view all the answers

<p>The normal serum potassium level ranges from 3.5 to 5.0 mEq/L.</p> Signup and view all the answers

<p>The two components of the cardiac cycle are diastole and systole.</p> Signup and view all the answers

<p>Cardiac output is the amount of blood ejected from the ventricle in one minute, calculated as CO = SV x HR.</p> Signup and view all the answers

<p>Preload is the amount of blood delivered to the heart chamber, which depends on venous return.</p> Signup and view all the answers

<p>The electrical conduction system generates and conducts impulses rapidly, coordinating heartbeats.</p> Signup and view all the answers

<p>Early repolarization involves a phase where the membrane potential begins to return towards the resting state after depolarization.</p> Signup and view all the answers

<p>Maintaining electrolyte balance is crucial for proper cardiac depolarization and function.</p> Signup and view all the answers

<p>Late rapid repolarization is the phase where the membrane potential sharply decreases, allowing the cell to return to its resting state.</p> Signup and view all the answers

<p>The primary components are the heart, blood vessels, and blood.</p> Signup and view all the answers

<p>The right ventricle receives deoxygenated blood, while the left ventricle receives oxygenated blood.</p> Signup and view all the answers

<p>The pericardium fixes the heart to the thoracic cavity and holds serous fluid to prevent friction.</p> Signup and view all the answers

<p>The valves are the pulmonic valve, aortic valve, mitral valve, and tricuspid valve.</p> Signup and view all the answers

<p>Deoxygenated blood enters the right atrium from the superior and inferior vena cava, moves to the right ventricle, and is pumped to the pulmonary circulation.</p> Signup and view all the answers

<p>The left atrium receives oxygenated blood from the pulmonary veins and sends it to the left ventricle.</p> Signup and view all the answers

<p>The vascular system transports blood throughout the body, consisting of systemic and pulmonary circulation.</p> Signup and view all the answers

<p>Arteries carry blood away from the heart.</p> Signup and view all the answers

<p>The pulmonary artery carries deoxygenated blood to the lungs for oxygenation.</p> Signup and view all the answers

<p>Veins have thinner walls and larger lumens compared to arteries, which have thicker walls and smaller lumens.</p> Signup and view all the answers

<p>They cause coronary vasodilation and reduce myocardial metabolic requirements.</p> Signup and view all the answers

<p>Pericarditis is the inflammation of the pericardium, which can lead to pericardial effusion and cardiac tamponade.</p> Signup and view all the answers

<p>Stenotic disease restricts forward blood flow, while regurgitant disease allows backward blood flow.</p> Signup and view all the answers

<p>Myocarditis is the inflammation of the myocardium, often indicating an underlying infection or inflammatory condition.</p> Signup and view all the answers

<p>Infective endocarditis involves infective organisms invading the endothelial lining, resulting in vegetation on the heart valves.</p> Signup and view all the answers

<p>Preload, afterload, contractility, wall motion abnormalities, and valvular dysfunction.</p> Signup and view all the answers

<p>Frank Starling's Law states that the strength of heart contractions is proportional to the volume of blood filling the heart (preload) before contraction.</p> Signup and view all the answers

<p>It increases heart rate, conduction speed, and contractility in the ventricles.</p> Signup and view all the answers

<p>Baroreceptors sense changes in blood pressure and help regulate it by providing feedback to the autonomic nervous system.</p> Signup and view all the answers

<p>Intermediate control involves the activation of the renin-angiotensin-aldosterone system and vasopressin secretion, leading to increased vascular resistance.</p> Signup and view all the answers

<p>MAP can be estimated by the formula: MAP = Diastolic pressure + (Pulse pressure / 3) or MAP = (2 × Diastolic pressure + Systolic pressure) / 3.</p> Signup and view all the answers

<p>The long-term control mechanism involves the kidneys altering sodium and water balance to restore blood pressure to normal levels.</p> Signup and view all the answers

<p>Afterload is the resistance the heart must overcome to eject blood, and increased afterload decreases stroke volume.</p> Signup and view all the answers

<p>Increased contractility enhances cardiac output by improving the heart's ability to pump blood effectively.</p> Signup and view all the answers

<p>The sympathetic nervous system increases heart rate and contractility, while the parasympathetic nervous system decreases heart rate and conduction speed.</p> Signup and view all the answers