Ch. 25 PrepU Questions
What is considered a normal right atrial pressure? 10 mm Hg 20 mm Hg 30 mm Hg 0 mm Hg
0 mm Hg Explanation: The normal right atrial pressure is about 0 mm Hg, which is equal to atmospheric pressure. It can increase to 20 to 30 mm Hg in conditions such as right-sided heart failure.
A client has suffered chest injuries following a automobile accident. The chest injury has resulted in an increase in intrathoracic pressure. There can be a transient shift from the pulmonary to the systemic circulation of how much blood? 200 mL 300 mL 150 mL 250 mL
250 mL Explanation: An increase in intrathoracic pressure, which impedes venous return to the right heart, can produce a transient shift from the pulmonary to the systemic circulation of as much as 250 mL of blood.
Which neurotransmitter is associated with the parasympathetic nervous system? Dopamine Norepinephrine Epinephrine Acetylcholine
Acetylcholine Explanation: The actions of the autonomic nervous system are mediated by chemical neurotransmitters. Acetylcholine is the postganglionic neurotransmitter for parasympathetic neurons and norepinephrine is the main neurotransmitter for postganglionic sympathetic neurons. Sympathetic neurons also respond to epinephrine, which is released into the bloodstream by the adrenal medulla. The neurotransmitter dopamine can also act as a neurotransmitter for some sympathetic neurons.
During a physical examination of a client, the nurse palpates the point of maximal impulse (PMI) in the seventh intercostal space lateral to the left midclavicular line. What is the mostappropriate action for the nurse to take? Auscultate both of the carotid arteries for the presence of a bruit. Document that the PMI is in the normal anatomic location. Assess the client for symptoms of left ventricular hypertrophy. Notify the physician.
Assess the client for symptoms of left ventricular hypertrophy. Explanation: When the hand is placed on the thorax, the main impact of the heart's contraction is felt against the chest wall at a point between the fifth and sixth ribs, a little below the nipple and approximately 3 inches to the left of the midline. This is called the point of maximum impulse (PMI). A PMI located outside these landmarks indicates possible cardiac enlargement, such as with left ventricular hypertrophy.
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: Pulmonic valve Tricuspid valve Aortic valve Bicuspid 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 distensibility of the blood vessel is the major factor in which of the vessel's characteristics? Laminar blood flow Resistance Compliance Wall tension
Compliance Explanation: Compliance refers to the total quantity of blood that can be stored in a given portion of the circulation for each millimeter rise in pressure. Compliance reflects the distensibility of the blood vessel. Wall tension, laminar blood flow, and resistance are not major factors in the distensibility of the blood vessel.
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 ventricle Right atrium Left 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.
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 Arteriosclerosis Lymphedema Venous stasis
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.
The nurse is reviewing the anatomy and physiology of the heart. What is the function of the right atrium? Receives blood returning to the heart from the systemic circulation Receives oxygenated blood from the lungs Pumps blood into the systemic circulation Pumps blood to the lungs Pumps blood into 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.
A client has prominent jugular veins. What type of medical problem is associated with prominent jugular veins? Shock Right-sided heart failure Left-sided heart failure Cerebrovascular accident (stroke)
Right-sided heart failure Explanation: Right-sided heart failure is seen with prominent jugular veins.
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 an increased cardiac output. 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 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.
A local athlete is getting prepared for the upcoming national track and field championships. Since this athlete is performing extreme exercise, what would be the most probable cardiac output? 8 to 12 L/minute 16 to 36 L/minute 2 to 4 L/minute 4 to 6 L/minute
16 to 36 L/minute Explanation: The average cardiac output in resting normal adults ranges from 4 to 6 L/minute. Less than this indicates cardiac disease. If a highly trained athlete is performing at an extreme exercise level, the heart may be required to pump four to six times this amount, or 16 to 36 L/minute.
The heart is a four-chambered muscular pump. In one day, how many gallons of blood are pumped throughout the body? 1500 1600 1800 1700
1800 Explanation: In one day, this pump moves more than 1800 gallons of blood throughout the body.
A client is lying in a recumbent position. In this client, approximately how much total blood volume is in the central circulation? 25% - 30% 15% - 20% 30% - 35% 20% - 25%
25% - 30% Explanation: In the recumbent position, approximately 25 to 30 percent of the total blood volume is in the central circulation.
A client with heart disease has the left ventricular ejection fraction measured. What is the normal left ventricular ejection when determined by angiocardiography? 55% - 75% 65% - 85% 35% - 55% 45% - 65%
55% - 75% Explanation: The normal left ventricular ejection fraction is usually 55 percent to 75 percent when determined by angiocardiography.
The semilunar valves of the heart open at the onset of the ejection period. Approximately what percentage of the stroke volume is ejected during the first quarter of systole? 40% 70% 50% 60%
60% Explanation: Approximately 60 percent of the stroke volume is ejected during the first quarter of systole.
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? Point of maximum impulse is located midclavicular at the 5th intercostal space Blood pressure of 146/80 A heart rate (HR) of 62 beats/minute An ejection fraction of 40%
An ejection fraction of 40% Explanation: 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.
When a client experiences the Cushing reflex, what occurs with the body? The pupils contract in response to light exposure. The systemic blood pressure decreases to restore equal amounts of oxygen throughout the body. An increase in arterial pressure to levels above the intracranial pressure The toes fan outward in response to stimulation being applied to the bottom of the foot.
An increase in arterial pressure to levels above the intracranial pressure Explanation: This reflex produces a rise in arterial pressure to levels above intracranial pressure so that the blood flow to the vasomotor center can be reestablished. Pupil contraction (papillary response) and the toe fanning (positive Babinski) do not relate with the Cushing reflex; neither does the oxygen supply to the body.
The circulatory system can be divided into two parts. What does the systemic circulation include? Select all that apply. Capillaries Pulmonary artery Aorta Right heart
Aorta Capillaries Explanation: The systemic circulation includes the aorta and capillaries. The pulmonary circulation includes the right heart and pulmonary artery.
A nurse is reviewing an echocardiogram for a client with a congenital defect in the papillary muscles of the heart. Based on this result, which assessment should the nurse complete? Auscultate for an extra heart sound due to incomplete semilunar valve closure. Palpate the pericardium for a heave or thrill. Monitor the blood pressure. Auscultate for a murmur caused by the backward expulsion of blood through the atrioventricular valves.
Auscultate for a murmur caused by the backward expulsion of blood through the atrioventricular valves. Explanation: When closed, the AV valves prevent backflow of blood from the ventricles to the atria during systole. The AV valves are supported by the papillary muscles, which project from the wall of the ventricles. Contraction of the papillary muscles at the onset of systole ensures closure by producing tension on the leaflets of the AV valves before the full force of ventricular contraction pushes against them.
Select the correct sequence of blood return to the heart. Capillaries, venules, veins, right atrium Capillaries, venules, veins, left atrium Capillaries, arterioles, arteries, right atrium Capillaries, arterioles, 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 left side of the heart to the lungs 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 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 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).
Considering how hydrostatic forces affect the capillaries, which of the following would increase capillary hydrostatic pressure most?
Increase in venous pressure Explanation: Changes in venous pressure have a greater effect on the capillary hydrostatic pressure than do the same changes in arterial pressure. An increase in small artery and arterial pressures elevate capillary hydrostatic pressure.
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 heart rate Increased collateral circulation Increased urinary output Decreased urinary output
Decreased urinary output Explanation: 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.
A nurse is assessing a client's apical pulse. The nurse is palpating the point of maximum impulse between which ribs? Second and third Fourth and fifth Third and fourth Fifth and sixth
Fifth and sixth Explanation: When the hand is placed on the thorax, the main impact of the heart's contraction is felt against the chest wall at a point between the fifth and sixth ribs.
A grandmother who works as a cook at a nearby school was recently hospitalized when she lost an extensive amount of blood in a work-related accident. The grandmother tells the nurse that she heard that she would keep feeling faint until the brain made more blood. The nurse knows that when the blood pressure dropped, the pressure in the carotid arteries decreased. This was detected by baroreceptors in the carotid arteries. What did the baroreceptors do? Increase parasympathetic stimulation of the heart and blood vessels Stimulate the brain to form new red blood cells Increase sympathetic stimulation of the heart and blood vessels Inhibit renin release from the kidneys to promote fluid retention
Increase sympathetic stimulation of the heart and blood vessels Explanation: The baroreceptors in the carotid arteries increase sympathetic, not parasympathetic, stimulation of the heart and blood vessels. The baroreceptors do not stimulate the brain to form new red blood cells or inhibit renin release from the kidneys to promote fluid retention.
The lymph system correlates with the vascular system without actually being a part of the vascular system. Among other things, the lymph system is the main route for the absorption of fats from the gastrointestinal system. The lymph system empties into the right and left thoracic ducts, which are the points of juncture with the vascular system. What are these points of juncture?
Junctions of the subclavian and internal jugular veins Explanation: The lymph capillaries drain into larger lymph vessels that ultimately empty into the right and left thoracic ducts. The thoracic ducts empty into the circulation at the junctions of the subclavian and internal jugular veins. The lymphatic system only joins the vascular system in one place, so no other answer is accurate.
Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another? Laminar Axially 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).
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 Nitric oxide Calcium channel blocker
Nitric oxide Explanation: 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.
The nurse is teaching a client diagnosed with heart failure about preload. Which principle would be most appropriate to provide to the client? Preload is the ability of the heart to change its force of contraction. Preload represents the volume work of the heart. Preload determines the frequency by which the ventricles contract and blood is ejected. Preload is the pressure or tension work of the heart.
Preload represents the volume work of the heart. Explanation: Preload is the distending force that stretches the heart muscle just prior to work of the onset of ventricular contraction. It represents the volume of blood stretching the ventricular muscle fibers at 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 pressure or tension work of the heart refers to afterload. The ability of the heart to change its force of contraction refers to cardiac contractility. The frequency by which the ventricles contract and blood is ejected refers to heart rate.
The heart consists of four valves. Which are the semilunar valves? Select all that apply. Tricuspid Pulmonary Mitral Aortic
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.
The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent? Repolarization of the ventricles Depolarization of the ventricular conduction system Repolarization of the atrium 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.
If the parasympathetic neurotransmitter releases acetylcholine, the nurse should anticipate observing what changes in the ECG pattern? Complete cardiac standstill Slowing of heart rate to below 60 beats/minute Heart rate 150 beats/minute, labeled as supraventricular tachycardia Disorganized ventricular fibrillation
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).
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 venous system collects deoxygenated blood from the tissues. The arterial system distributes oxygenated blood to the tissues. The capillaries pump blood.
The arterial system distributes oxygenated blood to the tissues. The venous system collects deoxygenated blood from the tissues. 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 circulatory system is a closed system that is divided into two parts. Which statement is correct about the closed system? The high pressure pulmonary circulation provides oxygen and nutrients to the tissues. The low pressure pulmonary circulation links circulation and gas exchange in the lungs. The low pressure systemic circulation system provides oxygen and nutrients to the tissues. The high pressure systemic circulation system links circulation and gas exchange in the lungs
The low pressure pulmonary circulation links circulation and gas exchange in the lungs. Explanation: The low pressure pulmonary circulation links circulation and gas exchange in the lungs, and the high pressure systemic circulation provides oxygen and nutrients to the tissues.
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.
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.
The troponin complex is one of a number of important proteins that regulate actin-myosin binding. Troponin works in striated muscle to help regulate calcium-mediated contraction of the muscle. Which of the troponin complexes is diagnostic of a myocardial infarction? Troponin T and troponin I Troponin A and troponin C Troponin C and troponin T Troponin A and troponin I
Troponin T and troponin I Explanation: In clinical practice, the measurement of the cardiac forms of troponin T and troponin I is used in the diagnosis of myocardial infarction. Troponin C is not diagnostic of a myocardial infarction. Troponin A is not one of the troponin complexes.
A client with aortic insufficiency is experiencing an increase in afterload. The client will experience fatigue and activity intolerance due to: residual blood in heart following contraction. pressure applied to valves. resistance to ejection of blood from the heart. slow ventricular filling.
resistance to ejection of blood from the heart. Explanation: Afterload is the resistance to ejection of blood from the heart. Ventricular filling is known as preload. The residual blood left in the heart is the residual volume, and pressure is applied to the valves upon contraction.
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 molecular structure of actin and myosin and their effect on contraction. the physiologic function of chemoreceptors and baroreceptors. the relationship between venous return and stroke volume.
the relationship between venous return and stroke volume. Explanation: 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.
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 molecular structure of actin and myosin and their effect on contraction. the physiologic function of chemoreceptors and baroreceptors. the relationship between venous return and stroke volume. the high oxygenation needs of cardiac muscle and the role of coronary circulation.
the relationship between venous return and stroke volume. Explanation: 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.
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? 40%, 40%, 10%, and 10% 50%, 30%, 20%, and little blood 60%, 20%, 20%, and little blood 25%, 25%, 25%, and 25%
60%, 20%, 20%, and little blood Explanation: 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.
When discussing the AV node's role in the electrical conduction of the heart with a client newly diagnosed with an AV block, which statements are accurate? Select all that apply. The AV node offers a two-way conduction area between the atria and the ventricles. The velocity of conduction through the AV junctional fibers is very fast, which greatly increases impulse transmission. When there is an AV block, impulses from the atria and ventricles beat independently of each other, so the heart rhythm is usually chaotic and irregular. A block at the AV bundle of His interferes with the normal delay of the impulse, thereby interfering with complete ejection of blood from the atria prior to ventricular contraction.
A block at the AV bundle of His interferes with the normal delay of the impulse, thereby interfering with complete ejection of blood from the atria prior to ventricular contraction. When there is an AV block, impulses from the atria and ventricles beat independently of each other, so the heart rhythm is usually chaotic and irregular. Explanation: The AV node connects the atrial and ventricular systems and normally provides for a one-way conduction between the atria and ventricles. The velocity of conduction through the AV junctional fibers is very slow, which greatly delays impulse transmission. A further delay occurs as the impulse travels through the transitional fibers and into the AV bundle, known as the bundle of His. This delay provides a mechanical advantage whereby the atria can complete their ejection of blood before ventricular contraction begins. Under normal circumstances, the AV node provides the only connection between the atrial and ventricular conduction systems. The atria and ventricles would beat independently of each other if the transmission of impulses through the AV node were blocked.
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. As the aneurysm grows, more tension is placed on the vessel wall, which increases the risk for rupture. Small diameter of this vessel will cause it to rupture more readily. The primary cause for rupture relates to increase in abdominal pressure, such as straining to have a bowel movement.
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.
When intracranial pressure (ICP) equals intra-arterial pressure, the central nervous system ischemic response is initiated. This response is directed at raising arterial pressure above ICP, thereby reestablishing blood flow to the vasomotor center of the brain. What is this response called? Cushing syndrome Cushing law Cushing reflex Cushing response
Cushing reflex Explanation: The Cushing reflex is a special type of central nervous system (CNS) reflex resulting from an increase in intracranial pressure (ICP). When the ICP rises to levels that equal intra-arterial pressure, blood vessels to the vasomotor center become compressed, initiating the CNS ischemic response. The purpose of this reflex is to produce a rise in arterial pressure to levels above ICP so that the blood flow to the vasomotor center can be reestablished. If the ICP rises to the point that the blood supply to the vasomotor center becomes inadequate, the vasoconstrictor tone is lost, and the blood pressure begins to fall. The elevation in blood pressure associated with the Cushing reflex is usually of short duration and should be considered a protective homeostatic mechanism. The brain and other cerebral structures are located within the rigid confines of the skull, with no room for expansion, and any increase in ICP tends to compress the blood vessels that supply the brain.
The lymph system correlates with the vascular system without actually being a part of the vascular system. Among other things, the lymph system is the main route for the absorption of fats from the gastrointestinal system. The lymph system empties into the right and left thoracic ducts, which are the points of juncture with the vascular system. What are these points of juncture? The internal and external jugular veins The bifurcation of the common carotid arteries Junctions of the subclavian and internal jugular veins The junction of the subclavian and the pulmonary veins
Junctions of the subclavian and internal jugular veins Explanation: The lymph capillaries drain into larger lymph vessels that ultimately empty into the right and left thoracic ducts. The thoracic ducts empty into the circulation at the junctions of the subclavian and internal jugular veins. The lymphatic system only joins the vascular system in one place, so no other answer is accurate.
Which organ has larger capillary pores to allow the exchange of gases, nutrients, and/or waste products? Blood-brain barrier Liver Kidney Brain
Liver Explanation: Liver capillaries have large pores so that substances can pass easily through the capillary wall, whereas the kidney has glomerular capillaries with fenestrations that assist with filtration. The brain has no involvement with the exchange of waste products.
The physician states that a client has adequate collateral circulation. The nurse interprets this as: Establishment of compensatory lymphatic drainage Anastomosis of the arterial and venous circulation Development of increased collagen 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 teaching a client the correct technique for taking an arterial pulse. The nurse explains that the pulsations are: Pressure pulses Turbulence of the blood flow Korotkoff sounds Blood flow in the veins
Pressure pulses Explanation: The arterial pressure pulse represents the energy that is transmitted from molecule to molecule along the length of the vessel. When taking a pulse, it is the pressure pulses that are felt. Pressure pulses have no direct relation to the blood flow. It is the pressure pulses that produce the Korotkoff sounds heard during blood pressure measurement. Pressure pulses would be felt even if there was no blood flow at all.
Colloidal osmotic pressure acts differently than the osmotic effects of the plasma proteins. What is its action? Pulls fluid back into the capillary Controls the direction of the fluid flow in the large arteries Pushes fluid into the extracellular spaces Pulls fluid into the interstitial spaces
Pulls fluid back into the capillary Explanation: 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.
A nurse is caring for a client with right heart failure caused by pulmonary hypertension. Which hemodynamic parameter is most appropriate for the nurse to monitor? Central venous pressure (CVP) Systemic vascular resistance (SVR) Pulmonary arterial pressure (PAP) Blood pressure
Pulmonary arterial pressure (PAP) Explanation: The pulmonary arterial pressure is the main source of afterload work on the right heart.
Hypoxia is said to have a negative inotropic effect on the heart, which means: the heart rate will slow down, so the atria and ventricles can fill better. the heart will adjust so that less time will be spent in diastole and filling of the ventricles will shorten. the cardiac output will decrease to cause less work for the heart. there will be interference in the generation of ATP, which is needed for muscle contraction.
there will be interference in the generation of ATP, which is needed for muscle contraction. Explanation: An inotropic influence is one that modifies the contractile state of the myocardium, independent of the Frank-Starling mechanism. Hypoxia exerts a negative inotropic effect by interfering with the generation of ATP, which is needed for muscle contraction. Hypoxia does not directly slow the heart rate, decrease cardiac output, or interfere with filling times. However, these can develop if the ability of the muscle to contract becomes severe and is not treated promptly.
