Patho CH24 Struc & Fxn of Cardiovascular System
The heart consists of four valves. Which are the heart's atrioventricular valves? Select all that apply. Tricuspid Mitral Pulmonary Aortic
A,B The heart's atrioventricular valves are the tricupsid and the mitral. The semilunar valves are the pulmonary and aortic. Chapter 25: Structure and Function of the Cardiovascular System, Heart Valves and Fibrous Skeleton, p. 610.
Which statements are true regarding the capillary system? Select all that apply. A. Flow out of the system is controlled by hydrostatic pressure. B. Albumin plays a significant role in maintaining the function of this system. C. Flow into the system is controlled by colloidal osmotic pressure. D. Normal function requires that all fluid that leaves the capillary beds be reabsorbed. E. Fluid leaves the capillary beds via lymphatic channels.
A,B,C The capillary hydrostatic pressure pushes fluids out of the capillaries, and the colloidal osmotic pressure exerted by the plasma proteins pulls fluids back into the capillaries. Albumin, which is the smallest and most abundant of the plasma proteins, provides the major osmotic force for return of fluid to the vascular compartment. Normally, slightly more fluid leaves the capillary bed than can be reabsorbed. This excess fluid is returned to the circulation by way of the lymphatic channels. Chapter 25: Structure and Function of the Cardiovascular System, Capillary-Interstitial Fluid Exchange, p. 625.
The difference between the end-diastolic and end-systolic volumes is called what? Stroke volume Cardiac output Ejection fraction Cardiac reserve
A Stroke volume is determined by the difference between end-diastolic and end-systolic volumes. Cardiac output is determined by stroke volume and heart rate. Ejection fraction is the volume ejected from the left ventricle. Cardiac reserve is determined by cardiac output. p. 612
Which blood vessel layer is made primarily of muscle? Tunica intima Tunica externa Tunica adventitia Tunica media
D The middle layer (tunica media) of a vessel is largely a smooth muscle layer that constricts to regulate and control the diameter of the vessel. The outermost layer of a vessel is called the tunica externa (or tunica adventitia) and is composed of loosely woven collagen fibers. The innermost layer is the tunica intima, which consists of a single layer of flattened endothelial cells. hapter 25: Structure and Function of the Cardiovascular System, Blood Vessels, p. 620.
The school nurse is doing a health class on the functional organization of the circulatory system. What is the function of the capillaries in the circulatory system? Distribute oxygenated blood to the tissues Collect deoxygenated blood from the tissues Exchange gases, nutrients, and wastes Pump blood
C The circulatory system consists of the heart, which pumps blood; the arterial system, which distributes oxygenated blood to the tissues; the venous system, which collects deoxygenated blood from the tissues and returns it to the heart; and the capillaries, where exchange of gases, nutrients, and waste takes place. Chapter 25: Structure and Function of the Cardiovascular System, Pulmonary and Systemic Circulations, pp. 615 - 616.
The heart is a four-chambered muscular pump. In one day, how many gallons of blood are pumped throughout the body? 1500 1600 1700 1800
D In one day, this pump moves more than 1800 gallons of blood throughout the body. p. 608
A client has had an acute myocardial infarction (MI). The brother of the client has a history of angina. The client asks how he will know if his brother's pain is angina or if the brother is actually having an MI. Which statement is correct? Chest pain with angina only occurs during the day; MI pain is more likely at night. Chest pain with angina only occurs at rest; MI pain occurs during a stressful time. Pain is more severe and lasts longer with angina than with an MI. Rest and intake of nitroglycerin relieve chest pain with angina; they do not relieve chest pain with an MI.
D Rest and intake of nitroglycerin relieve chest pain with angina but not with an MI. Pain with angina and MI is a subjective symptom for each client. Pain with angina and MI can occur at a variety of times. Chapter 25: Structure and Function of the Cardiovascular System, Endothelial Control of Vascular Function, p. 623.
If a client experiences sympathetic nervous stimulation of the heart, the nurse will observe which changes in manifestations? Increased heart rate and increased contractility Increased heart rate and decreased contractility Decreased contractility and decreased heart rate Decreased rate and force of contraction
A The sympathetic nervous system has an excitatory influence on heart rate and contractility, and it serves as the final common pathway for controlling the smooth muscle tone of the blood vessels. With stimulation of sympathetic nervous system, both heart rate and contractility would increase. Chapter 25: Structure and Function of the Cardiovascular System, Vascular Smooth Muscle, pp. 620 - 621.
Downstream peripheral pulses have a higher pulse pressure because the pressure wave travels faster than the blood itself. What occurs in peripheral arterial disease? The pulse decreases, rather than increases, in amplitude. The reflected wave is transmitted more rapidly through the aorta. Downstream peripheral pulses are increased even more than normal. Downstream peripheral pulses are greater than upstream pulses.
A With peripheral arterial disease, there is a delay in the transmission of the reflected wave so that the pulse decreases, rather than increases, in amplitude. Chapter 25: Structure and Function of the Cardiovascular System, Arterial Pressure Pulsations, p. 621.
The heart valves control the direction of blood flow. What is the function of the pulmonic valve? Controls the direction of blood flow from the left side of the heart to the lungs Controls the direction of blood flow from the right side of the heart to the systemic circulation Controls the direction of blood flow from the right side of the heart to the lungs Controls the direction of blood flow from the left side of the heart to the systemic circulation
C The heart valves control the direction of blood flow from the atria to the ventricles (the AV valves), from the right side of the heart to the lungs (pulmonic valve), and from the left side of the heart to the systemic circulation (aortic valve). p. 610
The physician states that a client has adequate collateral circulation. The nurse interprets this as: Anastomosis of the arterial and venous circulation Establishment of compensatory lymphatic drainage Development of increased collagen Long-term compensatory regulation of blood flow
D Collateral circulation is a mechanism for the long-term regulation of local blood flow. In the heart and other vital structures, anastomotic channels exist between some of the smaller arteries. These channels permit perfusion of an area by more than one artery. When one artery becomes occluded, these anastomotic channels increase in size, allowing blood from a patent artery to perfuse the area supplied by the occluded vessel. Lymph node removal requires establishment of compensatory lymphatic drainage. The aging process produces the development of increased collagen. p. 623.
Which of the following is true regarding pulmonary circulation? The system functions with an increased arterial pressure to circulate through the distal parts of the body. It is a low-pressure system that allows for improved gas exchange. It is the larger of the two circulatory systems. It consists of the left side of the heart, the aorta, and its branches.
B The pulmonary circulation consists of the right heart and the pulmonary artery, capillaries, and veins. It is the smaller of the systems and functions at a lower pressure to assist with gas exchange. pp. 615-616.
The nurse is reviewing the anatomy and physiology of the heart. What is the function of the right atrium? Receives oxygenated blood from the lungs Receives blood returning to the heart from the systemic circulation Pumps blood into the systemic circulation Pumps blood to the lungs
B The right atrium receives blood returning to the heart from the system circulation. The left atrium receives oxygenated blood from the lungs. The right ventricle pumps blood to the lungs. The left ventricle pumps blood into the systemic circulation. p. 608
A client's echocardiogram identified a narrowed valve that has resulted in a decreased blood flow between the left atria and left ventricle. The nurse would interpret this as the: Tricuspid valve Pulmonic valve Bicuspid valve Aortic valve
C The bicuspid valve (also called the mitral valve) controls the flow of blood between the left atria and left ventricle. The aortic valve controls flow between the left ventricle and aorta. The tricuspid controls the flow between the right atria and ventricle. The pulmonic valve controls flow between the right ventricle and pulmonary artery. Chapter 25: Structure and Function of the Cardiovascular System, Heart Valves and Fibrous Skeleton, p. 610.
If the parasympathetic neurotransmitter releases acetylcholine, the nurse should anticipate observing what changes in the ECG pattern? Heart rate 150 beats/minute, labeled as supraventricular tachycardia Disorganized ventricular fibrillation Complete cardiac standstill Slowing of heart rate to below 60 beats/minute
D Acetylcholine, the parasympathetic neurotransmitter released during vagal stimulation of the heart, slows down the heart rate by decreasing the slope of phase 4. The catecholamines, the sympathetic nervous system neurotransmitters epinephrine and norepinephrine, increase the heart rate by increasing the slope or rate of phase 4 depolarization. Fibrillation is the result of disorganized current flow within the ventricle (ventricular fibrillation). Fibrillation interrupts the normal contraction of the atria or ventricles. In ventricular fibrillation, the ventricles quiver but do not contract. Thus, there is no cardiac output, and there are no palpable or audible pulses (i.e., cardiac standstill). p. 615
The heart consists of four valves. Which are the semilunar valves? Select all that apply. Tricuspid Mitral Pulmonary Aortic
C,D The heart's semilunar valves are the pulmonary and aortic values. The heart's atrioventricular valves are the tricupsid and the mitral. Chapter 25: Structure and Function of the Cardiovascular System, Heart Valves and Fibrous Skeleton, p. 610.
Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another? Laminar Turbulent Crosswise Axially
A Laminar blood flow reduces friction by allowing the blood layers to slide smoothly over one another, with the axial layer having the most rapid rate of flow. Axially, crosswise, and turbulent blood flow would result in increased friction. In turbulent flow, the laminar stream is disrupted and the flow becomes mixed, moving radially (crosswise) and axially (lengthwise). Chapter 25: Structure and Function of the Cardiovascular System, Laminar versus Turbulent Flow, p. 619.
A client is admitted to the emergency department after experiencing a motor vehicle accident and sustaining multiple injuries with significant blood loss. The nurse predicts that the client will display which of the following? Decreased urinary output Increased urinary output Decreased heart rate Increased collateral circulation
A Stimulation of the sympathetic nervous system during stress or exercise causes local constriction of veins and arterioles due to the release of norepinephrine from sympathetic nerve endings. Increasing sympathetic activity causes constriction of some vessels, such as those of the skin, the gastrointestinal tract, and the kidneys. Vasoconstriction results in decreased blood flow to the kidneys and a compensatory decrease in urinary output and an increase in heart rate. Collateral circulation is a mechanism for long-term regulation of blood flow. Chapter 25: Structure and Function of the Cardiovascular System, Central Nervous System Responses, p. 628.
The cardiac cycle describes the pumping action of the heart. Which statement is correct about systole? Ventricles contract and blood is ejected from the heart. Atria contract and blood is ejected from the heart. Ventricles relax and blood fills the heart. Atria relax and blood fills the heart.
A Systole occurs when the ventricles contract and blood is ejected from the heart. Diastole occurs when the ventricles are relaxed and blood fills the heart. Chapter 25: Structure and Function of the Cardiovascular System, Cardiac Cycle, p. 611.
Which blood vessels function without the benefit of having walls comprised of three muscular layers? Capillaries Veins Arteries Arterioles
A The capillaries are small, thin-walled vessels that link the arterial and venous sides of the circulation and allow the exchange of oxygen and metabolites generated by the various tissues. The walls of all blood vessels, except the capillaries, are composed of three layers: tunica externa, tunica media, and tunica intima. Chapter 25: Structure and Function of the Cardiovascular System, SUMMARY CONCEPTS, p. 624.
Select the correct sequence of blood return to the heart. Capillaries, venules, veins, right atrium Capillaries, arterioles, arteries, right atrium Capillaries, arterioles, veins, left atrium Capillaries, venules, veins, left atrium
A The correct pathway for blood returning back to the heart is the capillaries, venules, veins, and right atrium. The other options do not support normal blood flow. Chapter 25: Structure and Function of the Cardiovascular System, Pulmonary and Systemic Circulations, p. 616.
Colloidal osmotic pressure acts differently than the osmotic effects of the plasma proteins. What is its action? Pulls fluid back into the capillary Pushes fluid into the extracellular spaces Controls the direction of the fluid flow in the large arteries Pulls fluid into the interstitial spaces
A The osmotic pressure caused by the plasma proteins in the blood tends to pull fluid from the interstitial spaces back into the capillary. This pressure is termed colloidal osmotic pressure so as to differentiate the osmotic effects of the plasma proteins, which are suspended colloids, from the osmotic effects of substances such as sodium and glucose, which are dissolved crystalloids. Chapter 25: Structure and Function of the Cardiovascular System, Osmotic Forces, p. 626.
The nurse identifies the blood vessel layer that constricts to regulate and control diameter as: Tunica media Tunica adventitia Tunica externa Tunica intima
A The tunica media, the middle layer, is largely a smooth muscle layer that constricts to regulate and control the diameter of the vessel. The tunica externa, also known as the tunica adventitia, refers to the outermost layer of a vessel. The tunica intima refers to the innermost layer that prevents platelet adherence and blood clotting. p. 620
When reviewing diagnostic test results and physical assessment data for a client with a history of stage II hypertension, which of the following would be of most concern to the nurse? An ejection fraction of 40% Blood pressure of 146/80 Point of maximum impulse is located midclavicular at the 5th intercostal space A heart rate (HR) of 62 beats/minute
A This ejection fraction is below normal (normal is about 55% to 75%) and indicates a poor prognosis. This low ejection fraction is a result of the complications of long-standing hypertension. Chapter 25: Structure and Function of the Cardiovascular System, Ventricular Systole and Diastole, Chapter 25: Structure and Function of the Cardiovascular System - Page 612
A client with a history of heart failure has the following echocardiogram results: heart rate 80 beats/minute; end-diastolic volume 120 mL; and end-systolic volume 60 mL. What is this client's ejection fraction (EF)? 2 mL 50% 0.80 180 mL
B Ejection fracture = stroke volume ÷ end-diastolic volume. Stroke volume equals the difference between end-diastolic and end-systolic volume. Therefore, EF = 60 ÷ 120, or 50%. p. 612.
A client asks why he has not had major heart damage since his cardiac catheterization revealed he has 98% blockage of the right coronary artery. The nurse's best response is: "You must have been taking a blood thinner for a long time." "You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked." "You are just a lucky person since most people would have had a massive heart attack by now." "With this amount of blockage, your red blood cells get through the vessel one by one and supply oxygen to the muscle."
B Collateral circulation is a mechanism for the long-term regulation of local blood flow. In the heart, anastomotic channels exist between some of the smaller arteries. These channels permit perfusion of an area by more than one artery. When one artery becomes occluded, these anastomotic channels increase in size, allowing blood from a patent artery to perfuse the area supplied by the occluded vessel. For example, persons with extensive obstruction of a coronary blood vessel may rely on collateral circulation to meet the oxygen needs of the myocardial tissue normally supplied by that vessel. There is no indication that the client is on a blood thinner. Chapter 25: Structure and Function of the Cardiovascular System, Heart Valves and Fibrous Skeleton, p. 610
During a physiology lecture, a nursing student hears about the different forms of muscle tissue. Which description best describes vascular smooth muscle? Depolarization of smooth muscle relies largely on intracellular potassium. Depolarization of smooth muscle relies largely on extracellular calcium. Smooth muscle requires more energy than skeletal muscle. Smooth muscle is exclusively under the control of parasympathetic neurons.
B Depolarization of smooth muscle relies largely on extracellular calcium, which enters through calcium channels in the muscle membrane. Sympathetic nervous system control of vascular smooth muscle tone occurs through receptor-activated opening and closing of the calcium channels. Smooth muscle uses only 1/10 to 1/300 the energy of skeletal muscle. Chapter 25: Structure and Function of the Cardiovascular System, Vascular Smooth Muscle, p. 621.
A nurse working with a client in heart failure is explaining why the symptoms of the heart failure were not evident for a long period of time. When describing the Frank-Starling mechanism, the nurse will explain: the high oxygenation needs of cardiac muscle and the role of coronary circulation. the relationship between venous return and stroke volume. the molecular structure of actin and myosin and their effect on contraction. the physiologic function of chemoreceptors and baroreceptors.
B The Frank-Starling principle addresses the relationship between venous return and stroke volume. It does not directly address the characteristics of actin and myosin. The principle is unrelated to coronary circulation, chemoreceptors and baroreceptors. Chapter 25: Structure and Function of the Cardiovascular System, Preload, p. 614.
A nurse is assessing a client who lost consciousness during a wrestling match when his opponent applied a neck hold. The client likely lost consciousness because: cardiac output suddenly dropped. a baroreceptor was stimulated. the position caused bradycardia. the client experienced temporary cardiac ischemia.
B The baroreceptors of the carotid body monitor blood pressure. The hold likely increased the pressure on the baroreceptor and mimicked an increase in BP, with a resultant extreme decrease in BP and unconsciousness. Neck pressure would be unlikely to cause ischemia, bradycardia, or a reduction in CO. Chapter 25: Structure and Function of the Cardiovascular System, Neural Control of Circulatory Function, p. 628.
A nurse is assessing a female client and notes that her left arm is swollen from the shoulder down to the fingers, with non-pitting edema. The right arm is normal. The client had a left-sided mastectomy 1 year ago. What does the nurse suspect is the problem? Venous stasis Lymphedema Arteriosclerosis Deep vein thrombosis
B The lymphatic system filters fluid at the lymph nodes and removes foreign particles such as bacteria. When lymph flow is obstructed, a condition called lymphedema occurs. Involvement of lymphatic structures by malignant tumors and removal of lymph nodes at the time of cancer surgery are common causes of lymphedema. Chapter 25: Structure and Function of the Cardiovascular System, The Lymphatic System, pp. 626 - 627.
The nurse is reviewing the circulatory system. Which statements are correct about the functional organization of the circulatory system? Select all that apply. The heart exchanges gases, nutrients, and wastes. The arterial system distributes oxygenated blood to the tissues. The venous system collects deoxygenated blood from the tissues. The capillaries pump blood.
B,C The circulatory system consists of the heart, which pumps blood; the arterial system, which distributes oxygenated blood to the tissues; the venous system, which collects deoxygenated blood from the tissues and returns it to the heart; and the capillaries, where exchange of gases, nutrients, and waste takes place. Chapter 25: Structure and Function of the Cardiovascular System, Pulmonary and Systemic Circulations, p. 615.
A client is diagnosed with an abdominal aortic aneurysm that the physician just wants to "watch" for now. When teaching the client about signs/symptoms to watch for, the nurse will base the teaching on which physiologic principle? Small diameter of this vessel will cause it to rupture more readily. The larger the aneurysm, the less tension placed on the vessel. As the aneurysm grows, more tension is placed on the vessel wall, which increases the risk for rupture. The primary cause for rupture relates to increase in abdominal pressure, such as straining to have a bowel movement.
C Because the pressure is equal throughout, the tension in the part of the balloon with the smaller radius is less than the tension in the section with the larger radius. The same holds true for an arterial aneurysm in which the tension and risk of rupture increase as the aneurysm grows in size. Wall tension is inversely related to wall thickness, such that the thicker the vessel wall, the lower the tension, and vice versa. Although arteries have a thicker muscular wall than veins, their distensibility allows them to store some of the blood that is ejected from the heart during systole, providing for continuous flow through the capillaries as the heart relaxes during diastole. p. 619.
The heart controls the direction of blood flow. What is the role of the aortic valve? Controls the direction of blood flow from the atria to the ventricles Controls the direction of blood flow from the left side of the heart to the lungs Controls the direction of blood flow from the left side of the heart to the systemic circulation Controls the direction of blood flow from the ventricles to the artia
C The heart valves control the direction of blood flow from the atria to the ventricles (the AV valves), from the right side of the heart to the lungs (pulmonic valves) and from the left side of the heart to the systemic circulation (aortic valve). Chapter 25: Structure and Function of the Cardiovascular System, Heart Valves and Fibrous Skeleton, p. 610
A client is admitted to the cardiac unit with a diagnosis of pericarditis. The nurse is teaching th client about the anatomical location of the infection. The nurse evaluates the effectiveness of the teaching when the client correctly identifies which of the following as the location of the pericardium? The outer muscular layer of the heart The innermost lining of the heart chambers A membranous sac that encloses the heart The electrical conduction system of the heart
C The pericardium forms a fibrous covering around the heart, holding it in a fixed position in the thorax and providing physical protection and a barrier to infection. The pericardium is a tri-layer sac consisting of a tough, outer fibrous layer and a thin, inner serous layer. Chapter 25: Structure and Function of the Cardiovascular System, Functional Anatomy of the Heart, p. 608
The heart is a four-chambered pump. What is the function of the right ventricle? Receives blood returning to the heart from the systemic circulation Receives oxygenated blood from the lungs Pumps blood to the lungs Pumps blood into the systemic circulation
C The right ventricle pumps blood to the lungs. The right atrium receives blood returning to the heart from the system circulation. The left atrium receives oxygenated blood from the lungs. The left ventricle pumps blood into the systemic circulation. Chapter 25: Structure and Function of the Cardiovascular System, The Heart, p. 611.
The stroke volume is the amount of blood ejected with every contraction of the ventricle. It is broken down into quarters. What is the approximate amount of the stroke volume per quarter? 25%, 25%, 25%, and 25% 50%, 30%, 20%, and little blood 40%, 40%, 10%, and 10% 60%, 20%, 20%, and little blood
D Approximately 60% of the stroke volume is ejected during the first quarter of systole, and the remaining 40% is ejected during the next two quarters of systole. Little blood is ejected from the heart during the last quarter of systole, although the ventricle remains contracted. Chapter 25: Structure and Function of the Cardiovascular System, Ventricular Systole and Diastole, p. 612.
Release of which humoral factors will result in vasodilation? Norepinephrine Angiotensin II Serotonin Histamine
D Histamine has a powerful vasodilator effect on arterioles and has the ability to increase capillary permeability, allowing leakage of both fluid and plasma proteins into the tissues. Norepinephrine, angiotensin II, and serotonin are all potent vasoconstrictors. Chapter 25: Structure and Function of the Cardiovascular System, Histamine, p. 623.
The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent? Depolarization of the sinoatrial node Depolarization of the ventricular conduction system Repolarization of the atrium Repolarization of the ventricles
D The P wave represents the depolarization of the sinoatrial node. The QRS complex represents the depolarization of the ventricles. The T wave represents repolarization of the ventricles, not the atrium. Chapter 25: Structure and Function of the Cardiovascular System, Cardiac Cycle, p. 612.
Nitroglycerin is the drug of choice in treating angina. What does nitroglycerin release into the vascular smooth muscle of the target tissues? Antithrombin factor Platelet-aggregating factor Calcium channel blocker Nitric oxide
D The fact that nitric oxide is released into the vessel lumen (to inactivate platelets) and away from the lumen (to relax smooth muscle) suggests that it protects against both thrombosis and vasoconstriction. Nitroglycerin, which is used in the treatment of angina, produces its effects by releasing nitric oxide in vascular smooth muscle of the target tissues. None of the other options are released by nitroglycerin. Chapter 25: Structure and Function of the Cardiovascular System, Vascular Smooth Muscle, pp. 620 - 621. Chapter 25: Structure and Function of the Cardiovascular System - Page 620 - 621
What does the nurse teach is the principal factor that determines how long the client can exercise? The client's age The client's mental status The client's medical history The client's heart and lung capacity
D The principal factor that determines how long and effectively a person will be able to exercise is the capacity of the heart, lungs, and circulation to deliver oxygen to the working muscles. Cardiac performance is influenced by the work demands of the heart and the ability of the coronary circulation to meet its metabolic needs. Chapter 25: Structure and Function of the Cardiovascular System, Regulation of Cardiac Performance, p. 614.
