Cardiovascular System Overview

LVEDV stands for Left Ventricular End-Diastolic Volume, and it is significant because it represents the volume of blood in the left ventricle at the end of diastole, influencing ejection fraction and overall cardiac efficiency.

During exercise, blood flow is reduced to organs with lower activity, like the stomach and kidneys, allowing more blood to reach working muscles which have a higher demand for oxygen and nutrients.

Training leads to increased ventricular volume, thicker ventricular walls due to hypertrophy, and improved force of contraction, all contributing to a higher stroke volume.

<p>The normal range for ejection fraction (EF) is 55–70%, and it is important because it indicates the percentage of blood ejected from the left ventricle with each heartbeat, reflecting heart health and efficiency.</p> Signup and view all the answers

<p>Regular cardiovascular training often results in decreased resting heart rate due to increased stroke volume, allowing the heart to pump more blood with fewer beats.</p> Signup and view all the answers

<p>The myocardium is the heart muscle tissue responsible for contractions that pump blood.</p> Signup and view all the answers

<p>A myocardial infarction occurs when blood flow to part of the myocardium is blocked, leading to damage and potential death of the heart tissue.</p> Signup and view all the answers

<p>The heart valves ensure that blood flows only in one direction within the heart.</p> Signup and view all the answers

<p>During systole, the atria contract to pump blood into the ventricles, which then contract to push blood into the lungs and the body.</p> Signup and view all the answers

<p>Blood pressure is the force exerted by circulating blood on the walls of blood vessels, measured by systolic pressure during ventricular contraction and diastolic pressure during heart rest.</p> Signup and view all the answers

<p>The electrical activity in the heart is initiated by the SA node, which sends signals through the atria.</p> Signup and view all the answers

<p>The P wave indicates the moment the SA node sends a signal that spreads through both atria.</p> Signup and view all the answers

<p>Intercalated discs in myocardium cells allow for communication and the passing of signals between cells for synchronized contraction.</p> Signup and view all the answers

<p>Red blood cells transport oxygen and nutrients throughout the body and carry carbon dioxide away for gas exchange.</p> Signup and view all the answers

<p>The AV node acts as a critical relay point for electrical signals, introducing a 0.1-second delay before transmitting signals from the atria to the ventricles.</p> Signup and view all the answers

<p>The QRS complex occurs when the ventricles contract after the signal reaches them through the Purkinje fibers.</p> Signup and view all the answers

<p>The skeletal muscle pump helps in venous return by increasing pressure in the veins when muscles contract, pushing blood back to the heart.</p> Signup and view all the answers

<p>Preload increases stroke volume by allowing the myocardium in the left ventricle to stretch, leading to a more forceful contraction.</p> Signup and view all the answers

<p>Cardiac output is the total volume of blood pumped by the heart per minute, calculated by multiplying heart rate (HR) by stroke volume (SV).</p> Signup and view all the answers

<p>Epinephrine increases the availability of calcium in the blood, enhancing the strength of ventricular contractions.</p> Signup and view all the answers

<p>Venoconstriction increases venous return to the heart by constricting veins when more blood is needed during exercise.</p> Signup and view all the answers

<p>The primary function of systemic circulation is to deliver oxygenated blood from the heart to the rest of the body and return deoxygenated blood back to the heart.</p> Signup and view all the answers

<p>Deoxygenated blood enters the heart from the superior and inferior vena cava, goes into the right atrium, passes through the tricuspid valve into the right ventricle, and is pumped into the pulmonary artery to reach the lungs.</p> Signup and view all the answers

<p>Coronary circulation refers to the blood supply to the heart muscle itself, delivering oxygen and nutrients essential for its function.</p> Signup and view all the answers

<p>The body responds by increasing heart rate (HR) and stroke volume (SV), which together raise cardiac output (Q) to meet the heightened oxygen demand.</p> Signup and view all the answers

<p>Cardiovascular drift refers to the phenomenon where stroke volume decreases slightly and heart rate increases to maintain cardiac output during prolonged exercise.</p> Signup and view all the answers

<p>Blood flow to the muscles increases from 15-20% of cardiac output at rest to 80-85% at maximum exercise, while flow to organs like the liver and kidneys is reduced.</p> Signup and view all the answers

<p>At VO2 max, stroke volume may plateau while heart rate continues to increase, leading to an overall increase in cardiac output.</p> Signup and view all the answers

<p>The heart is referred to as a double pump because it has two distinct circuits: one for systemic circulation and another for pulmonary circulation.</p> Signup and view all the answers