Chap 25 Patho Structure and Function of the Cardiovascular System
When the semilunar valves open it signals the onset of the ejection period. The aortic pressure reflects changes in the ejection of blood from which part of the heart? Right atrium Left ventricle Right ventricle Left atrium
Left ventricle Explanation: The aortic pressure reflects changes in the ejection of blood from the left ventricle, not the right ventricle or atrium.
The heart consists of four valves. Which are the semilunar valves? Select all that apply. Pulmonary Tricuspid Aortic Mitral
Pulmonary Aortic Explanation: The heart's semilunar valves are the pulmonary and aortic values. The heart's atrioventricular valves are the tricupsid and the mitral.
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? A membranous sac that encloses the heart The innermost lining of the heart chambers The electrical conduction system of the heart The outer muscular layer of the heart
A membranous sac that encloses the heart Explanation: 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.
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? The larger the aneurysm, the less tension placed on the vessel. The primary cause for rupture relates to increase in abdominal pressure, such as straining to have a bowel movement. Small diameter of this vessel will cause it to rupture more readily. As the aneurysm grows, more tension is placed on the vessel wall, which increases the risk for rupture.
As the aneurysm grows, more tension is placed on the vessel wall, which increases the risk for rupture. Explanation: 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.
The physician states that a client has adequate collateral circulation. The nurse interprets this as: Development of increased collagen Anastomosis of the arterial and venous circulation Establishment of compensatory lymphatic drainage Long-term compensatory regulation of blood flow
Long-term compensatory regulation of blood flow Explanation: 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.
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? Deep vein thrombosis Lymphedema Venous stasis Arteriosclerosis
Lymphedema Explanation: 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.
Which related circulatory complication can result from surgical treatment for metastatic breast cancer? Lymphedema in the affected arm Tachycardia when at rest Irregular heart rate Hypotension upon standing
Lymphedema in the affected arm Explanation: Involvement of lymphatic structures by malignant tumors and removal of lymph nodes at the time of cancer surgery are common causes of lymphedema. The other options are not related to the surgery that would have removed any affected lympth nodes.
Which factor represents the amount of blood that the heart must pump with each beat and is determined by the stretch of the cardiac muscle fibers and the actions of the heart prior to cardiac contraction? Cardiac contractility Preload Heart rate Afterload
Preload Explanation: Preload is the distending force that stretches the heart muscle just prior to the work of the onset of ventricular contraction. It represents the volume of blood stretching the ventricular muscle fibers at the end of diastole (i.e., end-diastolic volume) and is the sum of the blood remaining in the heart at the end of systole (end-systolic volume) and the venous return to the heart.
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 Pumps blood into the systemic circulation Receives oxygenated blood from the lungs Pumps blood to the lungs
Pumps blood to the lungs Explanation: 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.
The nurse is reviewing the anatomy and physiology of the heart. What is the function of the right atrium? Pumps blood to the lungs Receives blood returning to the heart from the systemic circulation Pumps blood into the systemic circulation Receives oxygenated blood from the lungs
Receives blood returning to the heart from the systemic circulation Explanation: 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.
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 Pumps blood to the lungs Pumps blood into the systemic circulation Receives blood returning to the heart from the systemic circulation
Receives blood returning to the heart from the systemic circulation Explanation: 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.
The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent? Depolarization of the ventricular conduction system Repolarization of the atrium Repolarization of the ventricles Depolarization of the sinoatrial node
Repolarization of the ventricles Explanation: 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.
The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent? Repolarization of the ventricles Repolarization of the atrium Depolarization of the ventricular conduction system Depolarization of the sinoatrial node
Repolarization of the ventricles Explanation: 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.
A client has prominent jugular veins. What type of medical problem is associated with prominent jugular veins? Cerebrovascular accident (stroke) Shock Right-sided heart failure Left-sided heart failure
Right-sided heart failure Explanation: Right-sided heart failure is seen with prominent jugular veins.
If the parasympathetic neurotransmitter releases acetylcholine, the nurse should anticipate observing what changes in the ECG pattern? Slowing of heart rate to below 60 beats/minute Complete cardiac standstill Disorganized ventricular fibrillation Heart rate 150 beats/minute, labeled as supraventricular tachycardia
Slowing of heart rate to below 60 beats/minute Explanation: 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).
Which sequence is the correct pathway for blood flow through the heart? left atrium - bicuspid valve - left ventricle - pulmonary artery - lungs - pulmonary vein - right atrium - tricuspid valve - right ventricle - aorta right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta right atrium - bicuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - tricuspid valve - left ventricle - aorta left atrium - tricuspid valve - left ventricle - pulmonary artery - lungs - pulmonary vein - right atrium - mitral valve - right ventricle - aorta
right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta Explanation: The correct pathway for blood flow through the heart is the right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta.
A client with heart disease has the left ventricular ejection fraction measured. What is the normal left ventricular ejection when determined by angiocardiography? 35% - 55% 45% - 65% 55% - 75% 65% - 85%
55% - 75% Explanation: The normal left ventricular ejection fraction is usually 55 percent to 75 percent when determined by angiocardiography.
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: Bicuspid valve Pulmonic valve Aortic valve Tricuspid valve
Bicuspid valve Explanation: 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.
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 ventricles to the artia 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 left side of the heart to the systemic circulation Explanation: 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).
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 the larger of the two circulatory systems. It is a low-pressure system that allows for improved gas exchange. It consists of the left side of the heart, the aorta, and its branches.
It is a low-pressure system that allows for improved gas exchange. Explanation: 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.
Downstream peripheral pulses have a higher pulse pressure because the pressure wave travels faster than the blood itself. What occurs in peripheral arterial disease? Downstream peripheral pulses are greater than upstream pulses. The reflected wave is transmitted more rapidly through the aorta. Downstream peripheral pulses are increased even more than normal. The pulse decreases, rather than increases, in amplitude.
The pulse decreases, rather than increases, in amplitude. Explanation: 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.
There are three main atrial pressure waves that occur during the cardiac cycle. What are the three main atrial pressure waves? Select all that apply. c a b v
a c v Explanation: There are three main atrial pressure waves that occur during the cardiac cycle: the a, c, and v waves.
Select the correct sequence of blood return to the heart. Capillaries, arterioles, veins, left atrium Capillaries, arterioles, arteries, right atrium Capillaries, venules, veins, right atrium Capillaries, venules, veins, left atrium
Capillaries, venules, veins, right atrium Explanation: 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.
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 right 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 left side of the heart to the systemic circulation 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 lungs Explanation: 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).
Humoral control of blood flow involves the effect of vasodilator and vasoconstrictor substances in the blood. Select the factor that has a powerful vasodilator effect on arterioles and increases capillary permeability. Norepinephrine Serotonin Histamine Prostaglandins
Histamine Explanation: 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 is a powerful vasoconstrictor. Serotonin causes vasoconstriction and plays a major role in control of bleeding. Prostaglandins produce either vasoconstriction or vasodilation.
Which of the following is true regarding pulmonary circulation? It consists of the left side of the heart, the aorta, and its branches. It is the larger of the two circulatory systems. 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 a low-pressure system that allows for improved gas exchange. Explanation: 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.
Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another? Axially Laminar Crosswise Turbulent
Laminar Explanation: 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).
Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another? Axially Laminar Turbulent Crosswise
Laminar Explanation: 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).
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. Rest and intake of nitroglycerin relieve chest pain with angina; they do not relieve chest pain with an MI. 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. Explanation: 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.
During an assessment of a client with ankle swelling, the nurse observes jugular venous pulsations 5 cm above the sternal angle when the head of his bed is elevated 45 degrees. What is the correct interpretation of this finding? The client has increased pressure related to right-sided heart failure. The client has stenosis of the jugular veins. The client has decreased fluid volume. The client has an increased cardiac output.
The client has increased pressure related to right-sided heart failure. Explanation: The jugular veins are normally flat or collapsed. Since there are no valves at the atrial sites (i.e., venae cavae and pulmonary veins) where blood enters the heart, they can become prominent in severe right-sided heart failure. This means that excess blood is pushed back into the veins when the atria become distended.
Which blood vessel layer is made primarily of muscle? Tunica media Tunica adventitia Tunica intima Tunica externa
Tunica media Explanation: 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.
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. Ventricles relax and blood fills the heart. Atria contract and blood is ejected from the heart. Atria relax and blood fills the heart.
Ventricles contract and blood is ejected from the heart. Explanation: 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.
A client with high blood pressure has swollen ankles. Which physiologic factor could relieve this condition? An increase in the colloidal pressure in tissue that drives the fluid into the tissue An increase in the colloidal pressure in circulation that drives fluid into the tissue A decrease in the hydrostatic pressure that drives fluid into the tissue An increase in the hydrostatic pressure that drives fluid into circulation
A decrease in the hydrostatic pressure that drives fluid into the tissue Explanation: The mean arterial pressure is the driving hydrostatic force and results in an increase of fluid in tissues. The colloidal pressure does influence fluid distribution but is not related to hypertension.
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 Pump blood Exchange gases, nutrients, and wastes Collect deoxygenated blood from the tissues
Exchange gases, nutrients, and wastes Explanation: 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.
The heart consists of four valves. Which are the heart's atrioventricular valves? Select all that apply. Mitral Aortic Tricuspid Pulmonary
Tricuspid Mitral Explanation: The heart's atrioventricular valves are the tricupsid and the mitral. The semilunar valves are the pulmonary and aortic.