9.24.F - Quiz: Cardiovascular System REVIEW.

List the five blood vessel divisions in the order that oxygenated blood would pass through them.

-arteries -arterioles -capillaries -venules -veins

Causes & Symptoms of Arrhythmias Arrhythmias can result from an improperly functioning conduction system, damaged cardiac muscle, or an imbalance of ions. Many factors can affect the functioning of the cardiac conduction system or the myocardium, such as having had a heart attack, smoking, congenital heart defects, and stress. Some substances or medicines may also contribute to arrhythmias. Symptoms of arrhythmias include Fast or slow heartbeat Skipping beats Lightheadedness or dizziness Chest pain Shortness of breath Sweating Electrocardiography or echocardiography can be used to determine the cause of an arrhythmia. Treatment to restore a normal heart rhythm may include medications, an implantable cardioverter-defibrillator (ICD) or pacemaker, or surgery.

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List & briefly describe the 3 electrical stages of a single heartbeat.

1. Atrial depolarization 2. Ventricular depolarization 3. Atrial and ventricular repolarization.

How many chambers does the heart have?

4

Identify the number of each of the 4 valves and provide their specific name.

4. Bicuspid (Mitral) Valve 5. Aortic Valve 12. Tricuspid Valve 11. Pulmonary Valve

At which point on the EKG is the SA node initiating the depolarization wave?

A

An arteriole is a small-diameter blood vessel that forms part of the micro-circulation that extends from an artery and leads to capillaries. Arterioles have muscular walls that usually consist of one or two layers of smooth muscle. They are the primary site of vascular resistance, which reduces the pressure and velocity of blood flow, enabling gas and nutrient exchange to occur within the capillaries.

A capillary is a small blood vessel with a wall that is one endothelial cell thick. They are the smallest blood vessels in the body: they convey blood between the arterioles and venules. These microvessels are a site of exchange of many substances with the interstitial fluid surrounding them. The more metabolically active the cells are, the more capillaries are required to supply nutrients and carry away waste products. A venule is a small blood vessel that allows deoxygenated blood to return from capillary beds to larger blood vessels called veins. Venules are extremely porous so that fluid and blood cells can move easily from the bloodstream through their walls. Veins are blood vessels that carry blood towards the heart. Veins are also called capacitance vessels because they contain 60% of the body's blood volume. Most carry deoxygenated blood from the tissues back to the heart, but the pulmonary veins carry oxygenated blood.

Describe what is happening at Letter G on the EKG regarding: A. Electrical event: B. Muscular event: C. Pathway of circulation:

A. no electrical event B. no muscular event C. no circulartion pathway

Describe what is happening at Letter C on the EKG regarding: A. Electrical event: B. Muscular event: C. Pathway of circulation:

A. no electrical event B. the av node is slowing down the signal C. AV and SL valves are closed

Which chemical promotes salt and water retention by the kidneys?

Aldosterone

This is intense chest pain caused by ischemia.

Angina

Which chemical is a potent vasoconstrictor and is used to regulate blood pressure?

Angiotensin II

Each side contains a(n) _____ that receives blood into the heart and directs it into a(n) ______ , which pumps the blood out of the heart.

Answer 1: atrium Answer 2: ventricle

The ____ causes the ____ which pushes the blood through the _____

Answer 1: depolarization (electrical event) Answer 2: contraction (muscular event) Answer 3: pathway of circulation

Fill in the blanks. The circulatory system is the system through which the blood is pumped around the body. The heart is the . The arteries are the . The arterioles are the . The capillaries are the . The veins are the

Answer 1:continuous Answer 2:pump Answer 3:conduits Answer 4:resistance vessels Answer 5:exchange sites Answer 6:blood reservoirs

Which one of the following is NOT a part of the aorta?

Aortic loop

Which valve prevents backflow into the left ventricle?

Aortic valve

What are the blood vessels that carry blood away from the heart under pressure?

Arteries

Which vessels are the primary site of vascular resistance, which reduces the pressure and velocity of blood flow?

Arterioles

This narrowing of the arteries increases peripheral resistance and hinders blood from traveling to the organs causing high blood pressure or hypertension.

Arteriosclerosis

Introduction Certain changes in heart and blood vessel function typically arise with age. These changes may be due to or worsened by modifiable factors that may lead to heart disease if untreated. The resting heart rate does not change significantly with the normal aging processes. However, when stressed by exercise or other factors, an aging heart may not pump blood as effectively as needed. Those aged 65 and older are more likely to develop heart disease, heart failure, or to suffer a heart attack than younger people. Heart disease, by limiting activity and diminishing quality of life, is also a major cause of disability in older people.

Arteriosclerosis Arteriosclerosis, or hardening of the arteries, is the most common aging change of the cardiovascular system. Arteriosclerosis is a condition that occurs when arteries narrow and become increasingly stiff, weakening them so that they can no longer effectively circulate blood throughout the body. This narrowing of the arteries increases peripheral resistance and hinders blood from traveling to the organs causing high blood pressure or hypertension. Atherosclerosis Atherosclerosis, a specific type of arteriosclerosis, results from the buildup of fat, cholesterol, and other substances on the artery walls called plaque. This buildup hardens and narrows the coronary arteries, and there is less space for blood to flow normally. The reduced flow of oxygen and nutrient-rich blood weakens and damages the cardiac muscle leading to heart failure. Risk Factors There are many risk factors for coronary artery disease. The modifiable (can be controlled) risk factors are high blood pressure and blood cholesterol levels, smoking, diabetes, obesity, lack of exercise, poor diet, and stress. Some examples of nonmodifiable factors are age, family history, race, post-menopausal women, and men older than 45. Common Symptoms A common symptom of arteriosclerosis is chest pain or discomfort, which may travel into the shoulder, arm, back, neck, or jaw. Occasionally it may feel like heartburn, and shortness of breath may also occur. Symptoms usually occur with exercise or emotional stress, last less than a few minutes, and improve with rest. In many cases, no symptoms are present, and the first sign is a heart attack, heart failure, or an abnormal heartbeat.

The Cardiac Cycle The cardiac cycle includes all events associated with blood flow through the heart during one complete heartbeat. It will be described primarily in terms of ventricular events. Each ventricle pumps the same volume of blood per beat, but the pressure changes on the heart's right side are only 20% of those occurring on the left side. This is due to the differences in the distance of each circulatory loop. 1. Systole = heart muscle contraction 2. Diastole = heart muscle relaxation Since the blood circulation is a continuous closed loop, an arbitrary starting point is used to follow the blood through the heart during a single cardiac cycle

Assuming an average heart rate of 75 beats/minute, the cardiac cycle length takes about 0.8 seconds. Atrial systole accounts for 0.1 seconds, while ventricular systole takes 0.3 seconds, with the remaining 0.4 seconds being the quiescent period of total heart relaxation. The flow of blood through the heart is controlled entirely by pressure changes due to the myocardium's alternating contraction and relaxation. Blood flows from high pressure to low pressure through any available opening. The pressure changes cause the opening and closing of heart valves to direct the blood flow. Heart Sounds Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. The sounds reflect the turbulence in blood flow created when the heart valves snap shut. Regarding the basic heart sounds: The first heart sound, "Lub," is caused by the closure of the AV valves. The second heart sound, "Dup," is caused by the closure of the SL valves.

Which one of the following is NOT correct regarding the atrial contraction phase?

Atrial pressure decreases.

Which point on the EKG represents atrial depolarization?

B

Changes in blood pressure are detected by this type of receptor located in the aortic arch and the carotid sinus.

Baroreceptors

How Circulation Is Accomplished The circulatory system is the continuous system through which the blood is pumped around the body. 1. The heart is the pump. 2. The arteries are the conduits. 3. The arterioles are the resistance vessels. 4. The capillaries are the exchange sites. 5. The veins are the blood reservoirs. Cardiac Output Blood pressure varies directly with cardiac output. Changes in SV or HR or both will cause corresponding changes in BP.

Blood Pressure Blood pressure is the pressure that blood exerts on the blood vessels' wall and is expressed in terms of millimeters of mercury (mmHg). The term is generally understood to mean the systemic arterial blood pressure in the largest arteries near the heart. The pressure originates in the heart's contraction, which forces blood out of the heart and into the blood vessels. Blood flows along a pressure gradient, moving from high to low areas of pressure. Arterial blood pressure rises and falls, corresponding to the phases of the cardiac cycle. Systolic pressure = maximum pressure achieved during ventricular contraction. Diastolic pressure = lowest pressure achieved during ventricular relaxation Blood pressure measurements are reported as a fraction of the systolic pressure over the diastolic pressure. The average blood pressure for a healthy adult is 120/70. The main factors influencing blood pressure are cardiac output, blood volume, and peripheral resistance. Blood pressure = cardiac output x peripheral resistance. Pressure results when cardiac output is opposed by peripheral resistance.

Which one of the following is NOT true regarding electrolytes?

Blood calcium levels are inversely proportional to their effect on stroke volume.

This value is expressed in terms of millimeters of mercury (mmHg).

Blood pressure

Which one of the following statements is NOT true regarding blood pressure?

Blood pressure varies inversely with blood volume.

Which vessels are the site of exchange for many substances with the interstitial fluid surrounding them?

Capillaries

Cardiac Output Cardiac output is defined as the amount of blood pumped out by EACH ventricle in one minute. It is the product of stroke volume (SV) and heart rate (HR) and varies with the demands on the body. Because normal blood volume is approximately 5 liters (5000 ml), the entire blood supply passes through the body once per minute, as indicated in the following calculation Cardiac Output The average adult resting cardiac output can be computed as follows: CO (ml/min) = HR (75 beats/min) x SV (70 ml/beat) = 5250 ml/min Cardiac reserve refers to the difference between the rate at which the heart pumps blood and its maximum capacity for pumping blood at any given time. It is the ability of the heart to push its cardiac output above normal levels. In non-athletic people, cardiac reserve is approximately four times the normal CO, but it may be up to seven times in trained athletes.

Cardiac Output We have seen that cardiac output is the product of stroke volume and heart rate. This volume of blood pumped throughout the body, as well as the rate at which it is pumped, changes to accommodate cellular requirements. Stroke Volume Stroke volume (SV) is the volume of blood pumped from each ventricle per beat. It can be calculated by subtracting the ventricle's blood volume just after the beat (called end-systolic volume or ESV) from the volume of blood just before the beat (called end-diastolic volume or EDV). SV (ml/beat) = EDV (120 ml/beat) - ESV (50 ml/beat) = 70 ml/beat

The difference between the rate at which the heart pumps blood and its maximum capacity for pumping blood at any given time is referred to as:

Cardiac reserve

Pacemakers An artificial cardiac pacemaker is a medical device that generates and delivers electrical impulses causing the heart muscle to contract and pump blood. This device replaces and/or regulates the function of the sinoatrial node of the heart. The primary purpose of a pacemaker is to maintain an adequate heart rate.

Cardioversion Cardioversion is a medical procedure by which an abnormally fast heart rate (tachycardia) or other cardiac arrhythmias (such as atrial fibrillation) can be converted to a normal rhythm using electricity and/or drugs. The procedure can be performed in conjunction with drug therapy until sinus rhythm is attained. After the procedure, the patient is monitored to ensure the stability of the sinus rhythm. If the patient is conscious, various drugs are often used to help sedate the patient and make the procedure more tolerable. If the patient is unstable or unconscious, the shock is given immediately upon confirmation of the cardiac issue. Cardioversion vs. Defibrillation Cardioversion aims to convert an arrhythmia back to sinus rhythm and is used when the patient has a pulse but is unstable and chemical therapy has failed or is unlikely to be successful. Defibrillation is the treatment for immediately life-threatening arrhythmias in which the patient does not have a pulse, such as ventricular fibrillation or pulseless ventricular tachycardia. The goal of both processes is to deliver an electrical stimulus to the heart. This stuns the heart momentarily, allowing the sinoatrial node to initiate a normal sinus rhythm.

Regulation of Blood Pressure Blood pressure is regulated by neural, chemical, and renal controls that continuously modify and adjust cardiac output, peripheral resistance, and blood volume. Neural Control: Short Term Regulation of Blood Pressure Neural control of blood vessels works to maintain adequate systemic blood pressure and alter blood distribution as needed. This short-term regulation of blood pressure is controlled by the autonomic nervous system (ANS) and modifies the peripheral resistance by changing the diameter of the arterioles.

Changes in blood pressure are detected by baroreceptors located in the aortic arch and the carotid sinus. Baroreceptors cannot regulate blood pressure long-term since the mechanism that triggers baroreceptors resets itself when adequate blood pressure is restored. Increased arterial pressure stretches the vessel wall, triggering the baroreceptors to feedback to the parasympathetic nervous system. This division of the ANS then reduces the heart rate and force of contraction through stimulation of the vagus nerve, causing a reduction in blood pressure. Decreased arterial pressure detected by baroreceptors triggers a sympathetic nervous system response. This stimulates an increase in heart rate and force of contraction, leading to increased blood pressure. Baroreceptor Reflex Renal Control: Long Term Regulation of Blood Pressure The kidneys provide the major long-term mechanism of blood pressure control. The direct mechanism by which the kidneys regulate blood volume is by adjusting the amount of water lost in the urine. As blood volume or blood pressure increases, the kidneys allow more water to be excreted in the blood. When blood pressure or blood volume decreases, water is conserved by the kidneys and returned to the bloodstream. Blood pressure falls as blood volume declines and vice versa.

These deliver oxygen-rich blood to the myocardium.

Coronary arteries

Which letter on the EKG represents the rapid ventricular depolarization?

D

What happens when the flow is too high for a particular area?

Damaged tissues and vessels

At which point are the ventricles completing their contraction?

E

MPORTANT POINT ON HOW IT ALL FITS TOGETHER: The depolarization (electrical event) causes the contraction (muscular event) which pushes the blood through the one-way pathway of circulation. There is a sequential dependence on these three processes. Each step on the EKG graphic below contains the full interaction of the Cardiac Conduction System, the Cardiac Cycle, and the Pathway of Circulation.

Electrical Events The term used for the release of an electrical stimulus is "depolarization," and the term for recharging is "repolarization." So, the 3 electrical stages of a single heartbeat are: 1. Atrial depolarization 2. Ventricular depolarization 3. Atrial and ventricular repolarization. In the heart's case, the SA node recharges whilst the atria are refilling, and the AV node recharges when the ventricles are refilling. In this way, there is no need for a pause in heart function. A typical EKG consists of three distinguishable waves called deflection waves, indicating the single heartbeat's three electrical stages. Explore the graphic below to see what is indicated by each wave, interval, and segment of the EKG. IMPORTANT POINT ON HOW IT ALL FITS TOGETHER: The depolarization (electrical event) causes the contraction (muscular event) which pushes the blood through the one-way pathway of circulation. There is a sequential dependence on these three processes.

The Cardiac Conduction System This conduction system consists of 5 elements: 1. The sino-atrial (SA) node 2. The atrioventricular (AV) node 3. The bundle of His (AV bundle) 4. The left and right bundle branches 5. The Purkinje fibers

Electrocardiography Electrocardiography is the process of producing an electrocardiogram (ECG or EKG). The body uses electrolytes located in the body fluids to conduct electrical currents. Since the human body is an excellent conductor, electrical changes caused by the cardiac conduction system can be detected on the body's surface and recorded using electrocardiography. An electrocardiogram (ECG or EKG) is the graphical representation of the heart's electrical activity and evaluates cardiac function. It is a graph of voltage versus time of the heart's electrical activity using electrodes placed on the skin. The Electrocardiogram The healthy heart has a sequential progression of depolarization (an electrical impulse) that starts with the sinoatrial node, spreads throughout the atrial walls, pauses at the atrioventricular node before proceeding down into the AV bundle and bundle branches on into the Purkinje fibers throughout the ventricles. This pattern of depolarization creates the characteristic ECG tracing. The ECG conveys a large amount of information about the function of its electrical cardiac conduction system

Match the layers of the heart wall to the correct description.

Epicardium- Composed of serous membrane to lubricate Myocardium- Composed of cardiac muscle to contract Endocardium- Composed of endothelium to reduce friction.

The blood flowing through the heart chambers does not nourish the heart tissues, as the myocardium is too thin for diffusion to occur.

FALSE

Cardiac Control For maximum efficiency, cardiac muscle needs organization (aka. rhythm) and speed control. So, two coordinating systems are required. The autonomic nervous system controls the speed of the heart rate and the force of the muscular contraction through the opposing effects of the sympathetic and parasympathetic nervous system divisions. These effects can only modify the activity of the intrinsic conduction system. The intrinsic conduction system (aka. nodal system, cardiac conduction system) consists of specialized nervelike, noncontractile cardiac cells that initiate and distribute impulses through the heart. The ability of the cardiac muscle to depolarize and contract is an intrinsic property of the heart muscle itself and does not depend on external nerve stimulation to occur. This organized distribution of impulses causes the myocardium to depolarize, then contract in a sequential manner.

Factors Affecting Heart Rate Temporary actions of neural, chemical, and physical homeostatic mechanisms can influence a healthy person's heart rate. The autonomic nervous system located in the medulla oblongata influences the heart rate via activation of cardiac centers to maintain a balance between the sympathetic and parasympathetic nervous systems. Activation of the cardioacceleratory center by the sympathetic nervous system results from emotional or physical stressors. The resulting release of norepinephrine stimulates the cardiac conduction system and the myocardium. This enhances both the force of contraction and the rate of heartbeat. Activation of the cardioinhibitory center by the parasympathetic nervous system opposes sympathetic effects. The release of acetylcholine reduces heart rate and contractility. Electrolytes are electrically charged particles (ions) in body fluids that hold the required electrical energy for many functions, including muscle contractions and nerve impulse transmission. Thus, they help trigger and conduct the electrical impulses in the heart. Electrolyte levels that are too high or too low can affect the heart's electrical impulses and contribute to arrhythmia development. Both potassium and calcium are needed in the proper amounts for muscle contraction and the proper conduction of the impulses through the cardiac conduction system. Physical factors, such as age, gender, fitness level, and body temperature, also affect heart rate.

Heart Rate The heart rate is the number of heartbeats per unit of time, usually per minute. The speed of the heartbeat varies as a result of physical activity, threats to safety, and emotional responses. The resting heart rate refers to the heart rate when a person is relaxed. This averages approximately 60-80 beats/minute (bpm). It is not only the speed of the heart rate that is important: the rhythm of the heartbeat is also crucial, and an irregular heartbeat can be a sign of a serious health condition.

Factors Affecting Stroke Volume Stroke volume depends on several factors such as heart size, contractility, duration of contraction, preload, and afterload. However, according to the Frank-Starling law of the heart, the critical factor is the degree to which the ventricles are stretched before contracting. The more they are stretched, the greater the contraction force will be (think of a rubber band!). This is known as preload. An increase in the volume or speed of venous return will increase preload and, through the Frank-Starling law of the heart, will increase stroke volume. Decreased venous return has the opposite effect, causing a reduction in stroke volume. To put it simply, as more blood comes into the ventricles, they have to stretch to receive the incoming volume. Then, they are able to contract more forcefully to pump out the same amount of blood that came in. This ensures equal outputs of the ventricles and proper blood volume distribution between the systemic and pulmonary circuits, thus preventing backup or the accumulation of blood in the cardiovascular system.

Which letter on the EKG represents the period from the beginning of ventricular depolarization leading to ventricular contraction and resulting in ventricular repolarization?

H

Which one of the following does NOT describe stroke volume?

Has an average value of 120 ml/beat

Blood Volume Blood volume is approximately 5.0 liters in a healthy adult, but it varies with body size, age, and male/female. Changes in blood volume change cardiac output affecting arterial pressure. A reduction in blood volume can occur through hemorrhage or extreme dehydration. Hypovolemia is a decrease in blood volume in your body, which can be due to blood loss or loss of body fluids. External injuries or internal bleeding can result in blood loss. Diarrhea and vomiting are common causes of excess body fluid loss. Hypervolemia occurs when blood volume increases and can occur through renal failure, congestive heart failure, liver failure, excessive sodium intake, or any other dysfunction of sodium regulation.

Hemodynamics - Blood Flow Blood flow, the movement of blood through the circulatory system, is directly proportional to blood pressure and inversely proportional to resistance. The body's tissues require a relatively consistent flow, so pressure and resistance are adjusted to maintain this consistency. Too high of a flow can damage blood vessels and tissue, while too low of a flow means tissues may not receive sufficient oxygen to function. Peripheral Resistance Peripheral resistance is a force produced by the friction between the blood flow and the blood vessels' walls. Blood flow must overcome peripheral resistance to push blood through the circulatory system. If resistance increases, either the pressure must increase to maintain flow, or the flow rate must reduce to maintain pressure. The three most important factors affecting resistance are: Blood viscosity (resistance to flow; "thickness" of a fluid): the greater the viscosity, the greater the resistance, and vice versa. Blood vessel length: the longer the vessel, the greater the resistance, and vice versa. Blood vessel diameter: the smaller the diameter, the greater the resistance, and vice versa. Arterioles can rapidly alter resistance by altering their radius through vasodilation or vasoconstriction.

Which letter on the EKG reflects the time the electrical impulse takes to travel from the sinus node through the AV node?

I

Arteries vs. Veins vs. Capillaries 1. Arteries and veins consist of three distinct layers, the tunica intima, tunica media, and tunica externa. In comparison, the much smaller capillaries are composed of a single layer. 2. Arteries are more muscular than veins, do not have valves, and carry blood away from the heart. 3. Veins are often closer to the skin and contain valves to help keep blood flowing toward the heart. The precise location of veins is much more variable than that of arteries, since veins often display anatomical variation from person to person. 4. The difference between veins and arteries is the direction of blood flow (out of the heart through arteries, back to the heart through veins), not their oxygen content.

Importance of Valves in Veins A major structural difference between arteries and veins is the presence of valves. In arteries, the blood is pumped under pressure from the heart, so backflow cannot occur. However, passing through the capillary network results in a decrease in blood pressure, meaning that backflow of blood is possible in veins. To counteract this, veins contain numerous one-direction valves that prevent backflow. As the vein is squeezed, it pushes blood through the valves, which then close to prevent backflow. Standing or sitting for prolonged periods can cause low venous return from venous pooling. In venous pooling, the smooth muscles surrounding the veins become slack, and the veins fill with the majority of the blood in the body, keeping blood away from the brain. This can cause unconsciousness. Two Methods Aid Venous Return Skeletal Muscle Pump: Veins within a muscle are compressed during the muscle contraction, causing an increase in blood pressure. This increase in pressure drives the blood towards the heart. Due to the presence of one-way valves, the blood can pass only in one direction, back towards the heart. The skeletal muscles of the legs are essential muscle pumps to prevent the pooling of the blood in the feet and calves due to gravity. Respiratory Pump: When muscles contract and relax during the inspiration and expiration process, pressure changes occur in the thoracic and abdominal cavities. These pressure changes compress the nearby veins and assist blood return to the heart. The Aorta The aorta, the main artery in the body, is divided into three parts: the ascending aorta, where the aorta leaves the heart and points superiorly toward the head; the aortic arch, where the aorta changes direction; and the descending aorta, where the aorta points inferiorly toward the feet.

According to the Frank-Starling law of the heart, an increase in the volume or speed of venous return will accomplish all of the following EXCEPT:

Increase heart size

This is when tissue is deprived of the oxygen that it needs to live.

Ischemia

Cardiac Arrhythmias A cardiac arrhythmia occurs when the cardiac conduction system is improperly transmitting the electrical impulses to the myocardium with the rate or rhythm of the heartbeat. The term arrhythmia means that the heart beats too quickly (tachycardia), too slowly (bradycardia), or with an irregular pattern. The most common type of arrhythmia is a fast, irregular heartbeat known as atrial fibrillation.

Issues with Valves The most common problems that impair the normal functioning of the valves are stenosis and regurgitation. Valvular Stenosis Valve stenosis refers to the narrowing of the valves preventing the valve from fully expanding, obstructing blood flow. The heart will have to work harder to pump blood to the body. Valve stenosis is often caused by calcium buildup or scarring from rheumatic fever and may result in cardiac hypertrophy (enlarging of the heart muscle) and, ultimately, heart failure. Valve replacement surgery is an option in some cases. Valvular Regurgitation Valve regurgitation refers to the backflow of blood caused by the failure of the valves to close completely. Regurgitation is the name for leaking heart valves that allow blood to flow backward in the heart. At other times, valve regurgitation places a strain on the heart. It can cause the heart to work harder and not pump the same amount of blood. This can result in a heart murmur and is generally a minor problem, but it can cause heart failure if severe enough. Symptoms may include shortness of breath, fatigue, lightheadedness, and a rapid, fluttering heartbeat. While some people may not need treatment, more severe cases may require medications, such as diuretics and blood thinners, or surgery.

Which one of the following is NOT a characteristic of the AV node?

It is located in the inferior portion of the interventricular septum.

Which one of the following statements does NOT apply to anti-diuretic hormone?

It is produced and stored by cardiomyocytes.

Which one of the following statements does NOT apply to atrial natriuretic peptide?

It is produced by the hypothalamus and stored & released by the posterior pituitary.

Which one of the following is NOT true regarding cardiac reserve?

It is the ability of the heart to hold blood in reserve until needed.

Which one of the following is NOT a role of the outer fibrous pericardium?

It provides lubrication to reduce friction from the movement of adjacent structures.

Which one of the following is NOT a characteristic of the SA node?

It recharges during the heart's quiescent period.

What will be the effect on stroke volume due to inappropriate levels of sodium and/or potassium ions?

It will decrease.

The major long-term blood pressure control mechanism is provided by which organ?

Kidneys

Where is the myocardium the thickest?

Left ventricle

Which one of the following applies only to the systemic circulation system?

Long loop circuit

Treatments Coronary artery disease cannot be cured, but treatment can help manage the symptoms and reduce the chances of serious problems such as heart attacks. Treatment can include lifestyle changes, such as regular exercise and stopping smoking, medications that reduce cholesterol, angioplasty (balloons and stents used to open narrow heart arteries), and coronary bypass surgery.

Myocardial Infarction Myocardial infarction is one of the most common causes of death worldwide. Any blockage of the coronary arteries can cause prolonged oxygen deprivation (aka. ischemia) 0f the heart muscle and trigger a myocardial infarction (aka. heart attack), causing serious damage. The clots that occlude the coronary arteries causing the infarction are usually the result of ruptured atherosclerotic plaques that break off and get stuck in the blood vessels. Transient periods of ischemia in the heart are associated with an intense chest pain called angina. This temporary ischemia and the resulting pain will resolve if the clot dissolves on its own. It is considered a warning sign of an impending heart attack. But if the clot remains and the time period of ischemia increases, the continuing hypoxic conditions will cause the cardiac muscle to die. Heart tissue does not regenerate, so myocardial infarction survivors will have permanent scar tissue in the myocardium that will reduce the heart's pumping capacity.

This is the scientific name for a heart attack.

Myocardial infarction (MI)

Which division of the nervous system reduces the heart rate and force of contraction through stimulation of the vagus nerve, causing a reduction in blood pressure?

Parasympathetic

Neural control is controlled by the autonomic nervous system and modifies which factor?

Peripheral resistance

Coronary Circulation The blood flowing through the heart chambers does not nourish the heart tissues, as the myocardium is too thick for diffusion to occur. Although the heart is approximately 1/200 of the body weight, it requires 1/20 of the blood supply, with the left ventricle receiving the largest portion. Coronary circulation is the circulation of blood through the vessels of the heart muscle. The vessels that deliver oxygen-rich blood to the myocardium are known as coronary or cardiac arteries. These arteries branch out from the aorta as it leaves the left ventricle. They run in the atrioventricular grooves and encircle the heart. The vessels that remove the deoxygenated blood from the heart muscle are known as coronary or cardiac veins. Any blockage of the coronary arterial circulation can be serious and even fatal.

Points to Emphasize Blood passes from systemic veins to systemic arteries ONLY AFTER first moving through the pulmonary circuit. The blood must be oxygenated in the lungs before returning to the systemic circulation to meet the body tissues' needs. Although the entire cardiac output of the right ventricle passes through the pulmonary circulation, only a small fraction of the left ventricle's output flows through any single organ.

Location of the Heart The heart is located between the lungs in the middle of the thoracic cavity, behind and slightly to the left of the sternum. The apex, or tip, is tilted slightly toward the left hip and rests on the diaphragm approximately the level of the 5th rib, while the posterosuperior base points toward the right shoulder beneath the 2nd rib. The heart, slightly larger than a fist, weighs less than one pound (200 to 425 grams).

Protection of the Heart The pericardium, a serous membrane, encloses the heart and is composed of two layers— an outer fibrous pericardium and an inner serous pericardium. The fibrous pericardium, composed of dense connective tissue, supports the heart and anchors it to the chest wall so that it doesn't move within the body. It protects the heart from nearby infections by completely separating it from the rest of the thoracic cavity and prevents the heart from overfilling with blood. Serous Pericardium The inner serous pericardium is made of two additional layers. The outer layer, the parietal layer, is continuous with the fibrous pericardium. The inner visceral layer (epicardium) encloses and protects the larger vessels and heart itself. The pericardial cavity, located between the inner and outer layers, contains pericardial fluid. The serous pericardium, with its two membranes and the fluid-filled pericardial cavity, protects the heart and provides lubrication to reduce friction from the movement of adjacent structures such as the diaphragm and the lungs

Two Circulatory Paths The heart is a double pump that serves two circulatory paths—pulmonary circulation and systemic circulation—each with its own set of blood vessels. The two circuits are linked to each other through the heart, creating a continuous cycle of blood through the body. Pulmonary circulation is the short loop circuit through the lungs where blood is oxygenated and is accomplished by the right side of the heart. Systemic circulation is the long loop circuit through the heart's left side that provides oxygenated blood to the body tissues. The heart also needs a supply of oxygenated blood to nourish the myocardium. The circulation of blood to the heart is called coronary circulation and is a subdivision of systemic circulation. Follow the pathway of blood through the heart structures. Recognize which structures carry oxygenated blood and which ones carry deoxygenated blood.

Pulmonary Circulation Pulmonary circulation is the movement of blood from the heart to the lungs for oxygenation, then back to the heart again. It does not serve the metabolic needs of the body tissues but functions only to bring blood in close contact with the alveoli of the lungs so that gas exchange can take place. Oxygen-depleted, dark red blood from the body enters the heart through the right atrium. The blood is pumped through the tricuspid valve into the right ventricle through the pulmonary SL valve and into the pulmonary trunk. The pulmonary trunk splits into the right and left pulmonary arteries to deliver the blood to each of the lungs. The blood travels into the alveolar-capillary beds of the lungs, where gas exchange occurs, removing carbon dioxide and adding oxygen to the blood. The bright red oxygenated blood then leaves the lungs through the right and left pulmonary veins, completing the pulmonary circuit. As the pulmonary circuit ends, the systemic circuit begins. Systemic Circulation Systemic circulation is the movement of blood from the heart through the body to provide oxygen and nutrients to the body's tissues while bringing deoxygenated blood back to the heart. From the pulmonary veins, oxygenated blood enters the left atrium and is pumped through the bicuspid valve (mitral valve) into the left ventricle. From the left ventricle, blood is pumped through the aortic SL valve and into the aorta. As the aortic branches continue to subdivide, the blood travels to the capillary beds of all body tissues, where gas exchange occurs, adding oxygen to the tissues and removing carbon dioxide. Deoxygenated blood returns to the heart through the systemic veins, which ultimately empty into the superior and inferior vena cavae to return blood to the pulmonary circuit.

Which vessel(s) carry oxygenated blood?

Pulmonary veins

Which one of the following does NOT aid in venous return?

Relaxed vessel walls

Which one of the following does NOT apply to the coronary arteries?

Remove the deoxygenated blood from the heart muscle

Chemical Controls: Long Term Regulation of Blood Pressure Numerous blood-borne chemicals influence blood vessel diameter and affect peripheral resistance. Anti-Diuretic Hormone (ADH) is produced by the hypothalamus, stored & released by the posterior pituitary, and stimulates the kidneys to conserve water. This is usually in response to dangerously low blood pressure as during a severe hemorrhage. It helps restore blood pressure through intense vasoconstriction. Atrial natriuretic peptide (ANP) is produced and stored by cardiomyocytes. It is released in response to high blood pressure. It acts against aldosterone's influence, making the kidneys excrete more sodium and water to cause the blood volume (& blood pressure) to drop.

Renal Control: Long Term Regulation of Blood Pressure The indirect mechanism of blood pressure control is through the renin-angiotensin-aldosterone system (RAAS). Activation of the renin-angiotensin-aldosterone (RAAS) system increases sodium retention by the kidneys, leading to reduced water loss into the urine, causing blood volume to increase. Where sodium goes, water follows. When arterial blood pressure declines, specialized kidney cells (juxtaglomerular cells) release renin into the blood. Renin regulates angiotensinogen's conversion to angiotensin I, which is then converted to angiotensin II using angiotensin-converting enzyme (ACE). Angiotensin II is a potent vasoconstrictor, which increases peripheral resistance causing increased blood pressure. Angiotensin II also stimulates the adrenal cortex resulting in the release of aldosterone. Aldosterone promotes salt and water retention. More sodium collects in the kidney tissue, and the water follows by osmosis. This results in decreased water excretion, thus increasing the blood volume and blood pressure.

These branches of the aorta provide blood for the kidneys.

Renal arteries

Which structure functions to keep the oxygenated blood and the deoxygenated blood separated?

Septum

This branch of the aorta provides blood for the spleen.

Splenic artery

This term refers to the narrowing of the valves preventing the valve from fully expanding, obstructing blood flow.

Stenosis

Stroke volume will increase due to which one of the following factors?

Sympathetic stimulation

The human body is a double system. It has two separate systems of blood flow. Which system provides oxygenated blood to the entire body?

Systemic circulation

During which phase does the heart contract and pump blood to where it needs to go?

Systole

The left side of the heart pumps blood throughout the body.

TRUE

Which one of the following is NOT a factor that affects the flow of blood within the circulatory system? answer choices- Flow Resistance Tension Pressure

Tension

During the isovolumetric contraction phase of the cardiac cycle:

The AV valves and the SL valves are all closed.

During the isovolumetric relaxation phase of the cardiac cycle:

The AV valves and the SL valves are all closed.

The inner layer is the endocardium, composed of endothelial cells providing a smooth, elastic, friction-reducing surface for collecting and pumping blood. This tissue also covers the heart's valves and is continuous with the endothelium of the major blood vessels entering and leaving the heart. The Purkinje fibers are located just beneath the endocardium and send nervous impulses from the SA and AV nodes outside the heart into the myocardial tissues. The endocardium can become infected, which leads to a serious inflammatory condition called infective endocarditis.

The Layout of the Heart The heart consists of four chambers, two on each side. The wall between the left and right sides of the heart is called the septum. The septum functions to keep the oxygenated blood and the deoxygenated blood separated. Each side contains an atrium that receives blood into the heart and directs it into a ventricle, which pumps the blood out of the heart. The atria and ventricle on each side of the heart are linked together by valves that prevent the backflow of blood. Atria The atria (singular - atrium) are receiving chambers and are located on the heart's superior aspect, with one atrium on each side. The right atrium receives deoxygenated blood from systemic circulation through the superior and inferior venae cavae. The left atrium receives oxygenated blood from pulmonary circulation through the left and right pulmonary veins. The atria are thin-walled muscular chambers. They do not need great pumping power since gravity causes most of the blood to flow passively into the ventricles. A small pouch called the auricle is located on each atrium and increases the atrial volume when needed.

Which one of the following statements about the conduction system is true?

The SA node of the heart acts as the pacemaker.

Aorta branches The ascending aorta has two small branches, called the left and right coronary arteries. These arteries provide blood to the heart muscle, and their blockage is the cause of myocardial infarctions or heart attacks. The arch of the aorta has three branches: the brachiocephalic artery, which itself divides into the right common carotid artery and the right subclavian artery; the left common carotid artery; and the left subclavian artery. These arteries provide blood to both arms and the head. The descending aorta is the largest artery in the body; it runs from the heart down the length of the chest and abdomen. It is sectioned into two portions—the thoracic aorta and the abdominal aorta—based on the cavity it is located in. The descending aorta branches into the two common iliac arteries within the abdomen that provide blood to the pelvis and, eventually, the legs.

The Vena Cavae The venae cavae are the veins with the largest diameter. Both enter the heart's right atrium, with the superior vena cava carrying blood from the arms, head, and thoracic cavity and the inferior vena cava carrying blood from the legs and abdomen. The inferior vena cava runs parallel to the abdominal aorta. The superior vena cava is formed from the brachiocephalic veins, which are in turn formed from the subclavian veins and internal jugular veins that serve the arm and head, respectively. The inferior vena cava is formed from the two common iliac veins that serve the legs and abdomen. The renal veins and hepatic veins from the kidneys and liver also feed into the inferior vena cava. Cardiovascular System The cardiovascular system's functions are to deliver oxygen and nutrients and to remove carbon dioxide and other waste products. Cells make the exchange of nutrients and wastes only with the fluid in their immediate vicinity. Changing and refreshing these fluids is necessary to prevent the buildup of waste and replenish the nutrient supply. The cardiovascular system is a closed-loop system consisting of the heart and blood vessels. Here are three main points about this system. 1. The heart pumps blood throughout the body for tissue oxygenation and gas exchange. 2. Blood vessels allow blood to circulate to all parts of the body. 3. The heart's left side deals with systemic circulation, while the right side of the heart deals with pulmonary circulation.

Which one of the following statements is true regarding the cardiac conduction system components?

The atrioventricular bundle branches transmit impulses through the myocardium of the septum to the Purkinje fibers of the ventricles.

The Heart Wall The heart wall has three different tissue layers. The outer layer, the epicardium (a.k.a. visceral pericardium), is composed of a serous membrane. The middle layer, the myocardium, is specialized cardiac muscle tissue responsible for contraction. The inner layer, the endocardium, is composed of endothelium to provide a frictionless surface to help the blood flow smoothly through the chambers. The endocardium becomes the inner lining of all blood vessels and also covers the heart valves. Cardiac tissue does not heal or regenerate when damaged; thus, it forms scar tissue when injured and restricts cardiac function by impairing muscle function.

The epicardium refers to the outer layer of the heart, which is also the inner visceral pericardium. The epicardium is a thin layer of elastic connective tissue that serves as an additional layer of protection from trauma or friction for the heart. This layer contains the coronary blood vessels carrying the blood supply to and from the heart muscle. The heart wall's middle layer is the myocardium, a muscular layer of cardiac muscle tissue responsible for the heart's ability to contract. The specialized cells called cardiomyocytes require a dedicated blood supply provided by the coronary arteries. Because of the continuous contractions required to deliver oxygen and nutrients and remove waste products such as carbon dioxide from the cardiac muscle tissue, the heart needs 1/20th of the blood supply to keep its tissue alive and working.

Which one of the following is NOT true regarding the heart rate?

The release of acetylcholine increases heart rate and contractility.

Which one of the following is NOT true regarding peripheral resistance?

The smaller the blood vessel diameter, the smaller the resistance, and vice versa.

Which one of the following is true regarding your heart rate?

The speed and rhythm of the heart rate are crucial to good health.

Which one of the following is NOT a true statement regarding the heart valves?

The structure of a heart valve allows blood flow into and out of each atria and ventricle.

The Frank-Starling law of the heart states that increasing preload will increase stroke volume. What two items does this ensure to maintain proper functioning of the cardiovascular system?

They are a increase of volume and speed

Which one of the following is NOT true regarding the Purkinje fibers?

They are located in the atrial walls.

Which valve prevents backflow into the right atrium?

Tricuspid valve

Blood Vessels Blood vessels are the cardiovascular organs that distribute blood throughout the body. There are five blood vessel divisions: arteries, arterioles, capillaries, venules, and veins. Arteries are blood vessels that carry blood away from the heart under pressure. Below is a micrograph of the cross-section of an artery showing the muscularity and elasticity of the arterial wall. Most arteries carry oxygenated blood; however, the pulmonary artery is the exception in that it carries deoxygenated blood to the lungs.

Valves The atrioventricular (AV) valves located between the atria and the ventricles on each side of the heart prevent the backflow of blood from the ventricles into the atria during systole (contraction). The AV valves are connected to the ventricles' trabeculae carnae muscles by the chordae tendineae, anchoring into papillary muscles. Blood passes through the valves along the pressure gradient (from high pressure to low pressure) during systole and diastole. The semilunar (SL) valves separate the ventricles from the great vessels on each side of the heart and prevent backflow from the greater vessels into the ventricles during diastole (relaxation). The structure of a heart valve allows blood flow in only one direction. The placement of the atrioventricular and semilunar heart valves determines the pathway of blood flow. Valves open or close based on pressure differences across the valve.

The mitral valve is on the left side of the heart and allows the blood to flow from the left atrium into the left ventricle. It is also known as the bicuspid valve because it contains two cusps. The tricuspid valve is the three-cusp valve on the right side of the heart between the right atrium and the right ventricle. The aortic SL valve separates the left ventricle from the aorta and has three cusps. The pulmonary SL valve (also called the pulmonic valve), which also has three cusps, separates the right ventricle from the pulmonary trunk.

Ventricles The ventricles are located on the inferior aspect of the heart and are the discharging or pumping chambers. The right ventricle pumps blood through the pulmonary vein and into the pulmonary circulation for gas exchange. The left ventricle pumps blood through the aorta into the systemic circulation to supply the body's tissues with oxygen. The ventricles have thicker, more muscular walls than those of the atria. The pressure required by the ventricles, which pump blood throughout the body and lungs, is much greater than the pressure required by the atria to fill the ventricles. Furthermore, the left ventricle has thicker walls than the right because it pumps blood to the entire body, while the right ventricle pumps only to the lungs, which is a shorter distance. The chordae tendinae are attached to papillary muscles in the ventricles. These two structures anchor the valve flaps to prevent the backflow of blood during ventricular systole. Superior view of transverse section through the atria

Which one of the following is NOT correct regarding the ventricular ejection phase?

Ventricles are in diastole.

Which one of the following is NOT correct regarding the ventricular contraction phase?

Ventricular pressure decreases.

Match each item to its correct value.

Ventricular systole- 0.3 seconds Quiescent period- 0.4 seconds Cardiac cycle length- 0.8 seconds

Name and give the function of each labeled cardiac conduction system structure.

WRITE IN YOUR OWN WORDS- A-The sino-atrial (SA) node- IT is the hearts internal pacemaker because t sets the basic rhythm of the beating heart B-The atrioventricular (AV) node- It briefly delays the stimulus (depolarization wave) so the contracting atria have enough time to pump all the blood into the ventricles C- The bundle of His (AV/ATRIOVENTRICULAR bundle)- IS a continuation of specialized tissue of the AV node it also transmits the electrical impulse to the myocardium of the septum from the AV node to the bundle branches D- The left and right (ATRIOVENTRICULAR) bundle branches- The left conducts the impulse through the myocardium of the septum to the Purkinje fibers of the left ventricle the right bundle conducts the impulse through the myocardium of the septum to the Purkinje fibers of the right ventricle E- The Purkinje fibers- They are able to rapidly transmit action potentials from the AV bundle and branches to the myocardium of the ventricles.

The atria are the receiving chambers of the heart. Regarding the right and left atria: A. Identify the type of blood received. B. Identify the specific circulation that the blood is received from. C. Identify the specific blood vessels that carry this blood.

WRITE IN YOUR OWN WORDS- A: The right atria receives deoxygenated blood, and the left atria receives oxygenated blood B and C: The specific circulation that the blood is received from for the right atria is from " systemic circulation through the superior and inferior venae cavae." The specific circulation that the blood is received from for the left atria is from " pulmonary circulation through the left and right pulmonary veins."

Trace the pathway of blood through the systemic circuit, beginning with the location in which blood enters the circuit and ending with the location in which blood leaves the circuit.

WRITE IN YOUR OWN WORDS- - oxygenated blood enters the left atrium from the pulmonary veins, -it's pumped through the bicuspid valve into the left ventricle. -blood is pumped through the aortic SL valve from the left ventricle, -and into the aorta. -, while the aortic branches continue to subdivide -the blood travels to every capillary beds of body tissues, there the gas exchange occurs, then adding oxygen to the tissues and removing carbon dioxide. -afterwards Deoxygenated blood returns to the heart through the systemic veins, then ultimately empty in both the superior and inferior vena cavae to return blood to the pulmonary circuit

Trace the pathway of blood through the pulmonary circuit, beginning with the location in which blood enters the circuit and ending with the location in which blood leaves the circuit.

WRITE IN YOUR OWN WORDS- =dark red Oxygen-depleted, blood from the body enters the heart through the right atrium. =The blood is now being pumped through the tricuspid valve into the right ventricle through the "pulmonary SL valve" and into the pulmonary trunk. =The pulmonary trunk splits into both pulmonary arteries(right and left) to deliver the blood to both lungs. =The blood travels into the alveolar-capillary beds of the lungs, where gas exchange occurs, therefore removing carbon dioxide and adding oxygen to the blood. =lastly, bright red oxygenated blood then leaves the lungs through the both pulmonary veins,(left and right) and the pulmonary circuit is completed

Define hypovolemia. Provide 2 causes of hypovolemia. Define hypervolemia. Provide 2 causes of hypervolemia.

WRITE IN YOUR OWN WORDS- Hypovolemia is a decrease in blood volume in your body, which can be due to blood loss or loss of body fluids. External injuries or internal bleeding can result in blood loss. Diarrhea and vomiting are common causes of excess body fluid loss. Hypervolemia occurs when blood volume increases and can occur through renal failure, congestive heart failure, liver failure, excessive sodium intake, or any other dysfunction of sodium regulation.

Discuss the cause and effect of venous pooling.

WRITE IN YOUR OWN WORDS- The cause is standing or sitting for long periods of time can "cause low venous return from venous pooling." The effect is during venous pooling smooth muscles "surrounding the veins become slack, and the veins fill with the majority of the blood in the body, keeping blood away from the brain." The result can cause one to fall into unconsciousness.

Cardiac Auscultation In cardiac auscultation, an examiner may use a stethoscope to listen for distinct sounds that provide important auditory data regarding the heart's condition. Locations to auscultate heart sounds The locations of best auscultation for each heart valve are labeled with "M," "T," "A," and "P." First heart sound, caused by atrioventricular valves—Mitral (M) and Tricuspid (T). Second heart sound, caused by semilunar valves— Aortic (A) and Pulmonary/Pulmonic (P).

What Is Echocardiography? Echocardiography is a test that uses high-frequency sound waves (ultrasound) to create pictures of the heart's chambers, valves, and walls, as well as the blood vessels (aorta, arteries, veins) attached to your heart. An echocardiogram is the actual picture, moving or still, of the heart structures resulting from the test. The Purpose Echocardiography examines the heart structures and their efficiency in moving blood through the heart, thus measuring how well the cardiac cycle events are being accomplished. It can provide a wealth of useful information, including the size and shape of the heart structures, the myocardium's ability to contract appropriately, and the location and extent of any tissue damage. Not only can an echocardiogram create ultrasound images of heart structures, but it can also produce an accurate assessment of heart function by measuring the blood flowing through the heart and calculating the cardiac output. The Procedure During this procedure, an ultrasound transducer placed on the chest sends out high-frequency sound waves at a frequency too high to be heard. The sound waves move through the skin and other body tissues to the heart tissues, where the waves bounce or "echo" off of the heart structures. The sound waves are sent to a computer and converted into moving images of the heart structures.

All events associated with blood flow through the heart during one complete heartbeat refers to the ___________________.

cardiac cycle

Cardiac arrhythmias can be treated by all of the following EXCEPT ________.

coronary bypass surgery

Coronary artery disease can be treated by all of the following EXCEPT ________.

defibrillation

What term refers to a graph of voltage versus time of the heart's electrical activity?

electrocardiogram

The process of detecting and recording the electrical changes caused by the cardiac conduction system is known as ________.

electrocardiography

The number of heartbeats per minute is known as the _____, while the volume of blood that is pumped by the ventricles with each heartbeat is the _____.

heart rate; stroke volume

List 3 factors that stroke volume depends on.

heart size, contractility, and duration of contraction

The ability of the cardiac muscle to depolarize and contract is a(n) ________ property of the heart muscle.

intrinsic

If the viscosity of blood decreases, what happens to the resistance?

it decreases

The effects of the autonomic nervous system can only _____________ the activity of the cardiac conduction system.

modify

Which one of the following has the primary purpose of maintaining an adequate heart rate?

pacemaker

Match the procedure to its description.

pacemaker- a medical device that generates and delivers electrical impulses causing the heart muscle to contract cardioversion- a medical procedure that converts an arrhythmia into a normal cardiac rhythm defibrillation- a medical procedure that treats an immediately life-threatening cardiac arrhythmia

Blood flows along a ________ gradient, moving from high to low.

pressure

What items are controlled by the autonomic nervous system?

speed of heart rate & force of contraction

The autonomic nervous system controls heart processes through the opposing effect of which two nervous system divisions?

sympathetic & parasympathetic

Which vessels are also called capacitance vessels because they contain 60% of the body's blood volume?

veins

If your patient's stroke volume is 55 ml/beat with a heart rate of 65 beats/min, what is the patient's cardiac output? Show your calculation setup including units. What is the average cardiac output, and how does this patient's CO compare? List TWO potential problems, if any, that may result from your patient's CO.

your own words- A. CO(ml/min)= HR (65 beats/min) x SV (55 ml/beat) = 3575 ml/min B. The aveage is 5250 ml/min the patients average is low C. Low blood pressure and low oxygen

Define end-diastolic volume (EDV) and provide the average value with units. Define end-systolic volume (ESV) and provide the average value with units. Use their values to calculate the average stroke volume (SV). Show your calculation setup and the answer with correct units.

your own words- EDV is the volume before the beat and ESV is the volume after the beat SV (ml/beat) = EDV (120 ml/beat) - ESV (50 ml/beat) = 70 ml/beat