Cardiovascular System: Heart Overview

To transport blood throughout the body, delivering oxygen and nutrients while removing waste products.

The heart is located posterior to the sternum and between the lungs in the thoracic cavity.

Arteries carry blood away from the heart, while veins bring blood toward the heart.

<p>The heart consists of the left atrium, right atrium, left ventricle, and right ventricle; the atria receive blood while ventricles pump it.</p> Signup and view all the answers

<p>The SA node initiates the action potential, serving as the primary pacemaker of the heart.</p> Signup and view all the answers

<p>The cardiac cycle consists of all events that occur during a heartbeat, essential for maintaining blood flow and pressure.</p> Signup and view all the answers

<p>Heart valves prevent backflow of blood, ensuring unidirectional flow through the heart.</p> Signup and view all the answers

<p>Capillaries are sites for exchange between blood and systemic cells, facilitating nutrient delivery and waste removal.</p> Signup and view all the answers

<p>The right side receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it to the body.</p> Signup and view all the answers

<p>Coronary vessels supply blood to the heart muscle itself, ensuring it receives oxygen and nutrients to function effectively.</p> Signup and view all the answers

<p>Common diseases include myocardial infarction, atherosclerosis, and circulatory shock.</p> Signup and view all the answers

<p>The refractory period prevents the heart from undergoing tetany, allowing for proper filling and pumping of blood.</p> Signup and view all the answers

<p>Cardiac output can be influenced by heart rate, stroke volume, and the efficiency of cardiac muscle contraction.</p> Signup and view all the answers

<p>The heart's conduction system and innervation by the autonomic nervous system control heart activity.</p> Signup and view all the answers

<p>The pulmonary trunk carries deoxygenated blood from the right ventricle to the lungs for gas exchange.</p> Signup and view all the answers

<p>The pulmonary semilunar valve and the aortic semilunar valve are located at the boundaries between ventricles and their associated arterial trunks.</p> Signup and view all the answers

<p>The pulmonary artery carries deoxygenated blood to the lungs, while the pulmonary veins carry oxygenated blood back to the left atrium.</p> Signup and view all the answers

<p>Deoxygenated blood is transported from the right atrium to the right ventricle, then through the pulmonary trunk to the lungs for oxygenation.</p> Signup and view all the answers

<p>The aorta carries oxygenated blood from the left ventricle to the systemic cells of the body.</p> Signup and view all the answers

<p>The tricuspid valve, located between the right atrium and right ventricle, prevents backflow of blood during ventricular contraction.</p> Signup and view all the answers

<p>Left ventricular impairment leads to pulmonary edema, causing fluid accumulation around the alveoli, which results in breathing difficulties.</p> Signup and view all the answers

<p>The right side serves pulmonary circulation, while the left side serves systemic circulation.</p> Signup and view all the answers

<p>The valves of the heart, including the AV and semilunar valves, open and close to ensure blood flows in one direction and prevents backflow.</p> Signup and view all the answers

<p>The pulmonary veins transport oxygenated blood from the lungs to the left atrium of the heart.</p> Signup and view all the answers

<p>To pump deoxygenated blood to the lungs for gas exchange and return oxygenated blood to the left atrium.</p> Signup and view all the answers

<p>The pericardium encases the heart and provides lubrication through serous fluid, protecting it from friction during movement.</p> Signup and view all the answers

<p>Systemic circulation delivers oxygenated blood from the left side of the heart to the body, while pulmonary circulation transports deoxygenated blood from the right side to the lungs.</p> Signup and view all the answers

<p>The aortic semilunar valve and the aorta facilitate this connection.</p> Signup and view all the answers

<p>The heart is located in the mediastinum, between the lungs, and is slightly rotated with the right side more anteriorly than the left.</p> Signup and view all the answers

<p>The visceral layer of the serous pericardium, also known as the epicardium, adheres to the heart.</p> Signup and view all the answers

<p>The pericardial cavity contains serous fluid, allowing smooth movement of the heart during the cardiac cycle.</p> Signup and view all the answers

<p>Blood flows from the right atrium through the right AV valve to the right ventricle, then through the pulmonary semilunar valve into the pulmonary trunk.</p> Signup and view all the answers

<p>The fibrous pericardium is made of dense irregular connective tissue.</p> Signup and view all the answers

<p>Deoxygenated blood drains into the right atrium through the superior vena cava, inferior vena cava, and coronary sinus.</p> Signup and view all the answers

<p>The three layers that cover the heart are the pericardium, visceral pericardium, and parietal pericardium.</p> Signup and view all the answers

<p>The pericardial cavity contains serous fluid that minimizes friction between the heart and surrounding structures as the heart beats.</p> Signup and view all the answers

<p>The right atrium, right ventricle, left auricle, and the aorta are prominently visible from the anterior view.</p> Signup and view all the answers

<p>The interventricular sulcus separates the left and right ventricles of the heart.</p> Signup and view all the answers

<p>Untreated pericarditis can lead to cardiac tamponade, limiting heart movement and causing heart failure.</p> Signup and view all the answers

<p>The heart wall consists of the epicardium (outer layer), myocardium (muscular middle layer), and endocardium (inner lining).</p> Signup and view all the answers

<p>The right atrium has the superior and inferior venae cavae attached to it from the posterior view.</p> Signup and view all the answers

<p>A friction rub is a clinical sign characterized by a crackling sound heard during auscultation.</p> Signup and view all the answers

<p>The left atrium, left ventricle, pulmonary veins, and inferior vena cava are visible from the posterior view.</p> Signup and view all the answers

<p>The epicardium is composed of simple squamous epithelium and an underlying layer of areolar connective tissue.</p> Signup and view all the answers

<p>Cardiomegaly is a general term for an enlarged heart, while hypertrophic cardiomyopathy refers specifically to the inward growth of the heart walls, primarily affecting the ventricles.</p> Signup and view all the answers

<p>Hypertrophic cardiomyopathy decreases cardiac output by narrowing the heart openings due to the thickening of the heart walls.</p> Signup and view all the answers

<p>Hypertrophic cardiomyopathy is often linked with high blood pressure and coronary heart disease.</p> Signup and view all the answers

<p>The two normal heart sounds are lubb (S1) and dupp (S2), which signify the closing of the heart valves.</p> Signup and view all the answers

<p>Valvular insufficiency occurs when cardiac valves leak due to improper closure, causing abnormal heart sounds known as heart murmurs.</p> Signup and view all the answers

<p>The myocardium is the thickest layer of the heart and is responsible for generating the force necessary to pump blood.</p> Signup and view all the answers

<p>The walls of the ventricles are thicker than those of the atria.</p> Signup and view all the answers

<p>The fossa ovalis is a depression in the interatrial septum that indicates where the fetal foramen ovale was located.</p> Signup and view all the answers

<p>Hypertrophic cardiomyopathy is a genetic disorder characterized by thickening of the heart muscle, making it harder to pump blood.</p> Signup and view all the answers

<p>Papillary muscles anchor the tendinous cords and help prevent backflow of blood by securing the atrioventricular valves during contraction.</p> Signup and view all the answers

<p>Semilunar valves have cusps shaped like half-moons, and they prevent backflow of blood into the ventricles.</p> Signup and view all the answers

<p>Cardiomegaly is the enlargement of the heart due to an increase in heart chamber size or heart wall thickness.</p> Signup and view all the answers

<p>Tendinous cords connect the papillary muscles to the atrioventricular valves, preventing valve inversion during ventricular contraction.</p> Signup and view all the answers

<p>The left ventricle has a much thicker wall than the right ventricle and is responsible for pumping oxygenated blood throughout the body.</p> Signup and view all the answers

<p>Heart valves prevent the backflow of blood, ensuring that it flows in the correct direction through the heart.</p> Signup and view all the answers

<p>Atrioventricular valves are located between the atria and ventricles, while semilunar valves are located at the bases of the pulmonary trunk and aorta.</p> Signup and view all the answers

<p>The endocardium lines the heart chambers and blood vessels, providing a smooth surface for blood flow.</p> Signup and view all the answers

<p>Aging and disease decrease the flexibility and elasticity of heart valves, potentially altering blood flow.</p> Signup and view all the answers

<p>The interatrial septum separates the left and right atria.</p> Signup and view all the answers

<p>-60 mV</p> Signup and view all the answers

<p>It reduces the heart rate to approximately 75 beats per minute.</p> Signup and view all the answers

<p>They allow Ca2+ to enter the cell, triggering depolarization.</p> Signup and view all the answers

<p>The AV node acts as the default pacemaker, establishing a rhythm of 40 to 50 beats per minute.</p> Signup and view all the answers

<p>The conduction rate slows down at the AV node, allowing ventricles to contract more effectively and prevent backflow of blood into the atria.</p> Signup and view all the answers

<p>They help the cells reach the threshold for spontaneous depolarization.</p> Signup and view all the answers

<p>K+ channels open, allowing K+ to exit the cell, returning the membrane potential to -60 mV.</p> Signup and view all the answers

<p>Propagation of an action potential and contraction of sarcomeres within the cardiac muscle cells.</p> Signup and view all the answers

<p>The average rate is one action potential per 0.8 seconds.</p> Signup and view all the answers

<p>An ectopic pacemaker is any pacemaker outside the SA node that can spontaneously depolarize.</p> Signup and view all the answers

<p>It slows down the conduction rate of action potentials, acting as a bottleneck.</p> Signup and view all the answers

<p>Purkinje fibers deliver repeated electrical impulses to heart muscle to sustain required heart rate and rhythm.</p> Signup and view all the answers

<p>A mechanical pacemaker delivers repeated electrical impulses to maintain a required heart rate and rhythm when the heart's natural system is failing.</p> Signup and view all the answers

<p>Approximately 0.8 seconds.</p> Signup and view all the answers

<p>The cardiac muscle cells of the atria contract first, followed by the contraction of the ventricular muscle cells.</p> Signup and view all the answers

<p>SA nodal cells depolarize due to Ca2+ influx, while neurons depolarize due to Na+ influx.</p> Signup and view all the answers

<p>An action potential spreads along the sarcolemma and stimulates contraction in the sarcomeres of the muscle cells.</p> Signup and view all the answers

<p>They facilitate almost simultaneous stimulation of cardiac muscle cells in the ventricles.</p> Signup and view all the answers

<p>They help establish and maintain the RMP of -60 mV by allowing K+ to exit and Na+ to enter the cells.</p> Signup and view all the answers

<p>It involves reaching threshold, followed by depolarization and then repolarization as ion channels open and close.</p> Signup and view all the answers

<p>It increases both heart rate and the force of contraction by stimulating the cardioacceleratory center.</p> Signup and view all the answers

<p>It ensures the action potential spreads effectively through the heart, enabling coordinated contractions.</p> Signup and view all the answers

<p>It leads to a decrease in heart rate by reducing conduction through the SA and AV nodes.</p> Signup and view all the answers

<p>They can lead to failure of cardiac muscle cells, causing damage or death to the myocardium.</p> Signup and view all the answers

<p>It refers to the heart chambers functioning as a single cell, allowing for synchronized contractions.</p> Signup and view all the answers

<p>Baroreceptors are sensors in the right atrium that detect blood pressure changes.</p> Signup and view all the answers

<p>They reach -40 mV at threshold due to the opening of voltage-gated cation channels.</p> Signup and view all the answers

<p>Depolarization occurs when voltage-gated Ca2+ channels open, causing the membrane potential to rise above 0 mV.</p> Signup and view all the answers

<p>Cardiac muscle relies primarily on aerobic respiration and has a reduced ability to switch to anaerobic glycolysis under stress.</p> Signup and view all the answers

<p>It decreases conduction velocity at the SA and AV nodes, leading to a reduction in heart rate.</p> Signup and view all the answers

<p>They rapidly conduct the action potential throughout the ventricles, facilitating coordinated ventricular contractions.</p> Signup and view all the answers

<p>During repolarization, K+ channels open, allowing K+ to flow out, returning the membrane potential to -60 mV.</p> Signup and view all the answers

<p>Clamped blood flow can lead to ischemia, causing dysfunction and potential cell death in cardiac muscles.</p> Signup and view all the answers

<p>It provides structural support, insulates electrical signals, anchors heart valves, and offers a framework for cardiac muscle attachment.</p> Signup and view all the answers

<p>Coronary circulation supplies the heart muscle with oxygenated blood, while blood flow through the heart chambers does not supply the heart tissue itself.</p> Signup and view all the answers

<p>Coronary arteries do not anastomose, meaning they lack connections to each other, which makes blockages critical.</p> Signup and view all the answers

<p>It supplies blood to the anterior wall of the left ventricle and most of the interventricular septum.</p> Signup and view all the answers

<p>Symptoms include severe chest pain, shortness of breath, nausea, and may also include fatigue or flulike symptoms in women.</p> Signup and view all the answers

<p>Intercalated discs, which contain desmosomes and gap junctions, allow for continuous action potential propagation and mechanical stability.</p> Signup and view all the answers

<p>The coronary sinus is a thin-walled vein that collects deoxygenated blood from the myocardium and empties into the right atrium.</p> Signup and view all the answers

<p>Cardiac muscle cells are branched, have intercalated discs, and are generally shorter, whereas skeletal muscle cells are longer and unbranched.</p> Signup and view all the answers

<p>Gap junctions provide low-resistance pathways for ions to flow, allowing action potentials to spread quickly between cardiac muscle cells.</p> Signup and view all the answers

<p>Valvular stenosis can be caused by scarring, decreased flexibility, or misshapen valves, leading to reduced blood flow and increased workload on the heart.</p> Signup and view all the answers

<p>The fibrous skeleton serves as an electrical insulator, preventing direct transmission between these two heart chambers.</p> Signup and view all the answers

<p>It supplies blood to the right ventricle and the posterior wall of both ventricles, crucial for maintaining myocardial health.</p> Signup and view all the answers

<p>A functional syncytium refers to a chamber of the heart behaving as a single unit due to intercalated discs' connections between cardiac muscle cells.</p> Signup and view all the answers

<p>Myoglobin binds oxygen in cardiac muscle cells during rest, ensuring an adequate supply of oxygen for aerobic respiration.</p> Signup and view all the answers