Chapter 14

Exchange between blood and interstitial fluid occurs across capillaries and, to a lesser extent, 1) A) veins. B) metarterioles. C) venules. D) arteries. E) arterioles.

Chemicals released by metabolically active cells will cause which of the following? 2) A) contraction of arteriolar smooth muscle to decrease blood flow B) contraction of capillary smooth muscle to increase blood flow C) contraction of arteriolar smooth muscle to increase blood flow D) relaxation of capillary smooth muscle to decrease blood flow E) relaxation of arteriolar smooth muscle to increase blood flow

Fenestrated capillaries are unique in their ability to 3) A) move molecules across endothelial cells by transcytosis. B) maintain a low permeability to small water-soluble molecules. C) allow few molecules to pass between endothelial cells. D) allow relatively large molecules to pass between endothelial cells E) restrict the passage of proteins across endothelial cells.

An increase in sympathetic nervous activity to arterioles will have little effect on vasoconstriction of the 4) A) brain and heart. B) heart and kidneys. C) kidneys. D) skeletal muscles. E) gastrointestinal tract

The lumen of every blood vessel is lined by a monolayer of what cell type? 5) A) endothelial cells B) smooth muscle cells C) erythrocytes D) fibroblasts E) platelets

Which of the following inaccurately represents normal forces across capillary walls? 6) A) Interstitial fluid oncotic pressure is almost zero. B) At rest, net filtration occurs across capillary walls. C) Interstitial fluid hydrostatic pressure increases from arteriole end to venous end. D) Capillary hydrostatic pressure decreases from arteriole end to venous end. E) Capillary oncotic pressure is due primarily to plasma proteins.

What are blood vessels that normally bypass capillary beds are called? 7) A) venules B) pararterioles C) pre-capillary sphincters D) A-V malformations E) metarterioles

Oxygen has what effect on systemic arterioles? 8) A) vasoconstriction and vasospasm B) vasospasm C) vasodilation D) vasoconstriction E) neither vasodilation or vasoconstriction, but may cause vasospasm

What region of the cardiovascular system contains valves? 9) A) heart only B) metarterioles only C) veins only D) both the heart and veins E) the heart, metarterioles, and veins

Which of the following equations correctly relates flow, pressure, and resistance? 10) A) flow = pressure + resistance B) flow = pressure × resistance C) resistance = flow × pressure D) pressure = flow × resistance E) flow = pressure - resistance

Arteries have ________ compliance and ________ resistance to flow. 11) A) low : low B) high : high C) low : high D) high : low E) zero : high

Which of the following structures contains high pressure baroreceptors? 12) A) aortic arch only B) carotid sinus only C) right atrium only D) both the aortic arch and carotid sinus E) aortic arch, right atrium, and carotid sinus

The contractile activity of smooth muscle cells within which type of blood vessel is primarily involved in the control of the organ blood flow and mean arterial pressure? A) veins B) capillaries C) arterioles D) venules E) arteries

A constriction of an arteriole in response to stretch of the arteriole smooth muscle is called 14) A) active hyperemia. B) hypoxia. C) myogenic response. D) reactive hyperemia. E) ischemia.

Resistance to blood flow is regulated primarily by what blood vessels? A) veins B) arterioles C) arteries D) ventricle E) capillaries

What is the purpose of extrinsic control of arteriolar smooth muscle contractile activity? 16) A) regulate blood flow through specific capillary beds B) regulate mean arterial pressure C) regulate stroke volume D) regulate heart rate E) regulate cardiac output

An increase in the concentration of which of the following within the interstitial space surrounding an arteriole would cause that vessel to constrict? 17) A) lactic acid B) adenosine C) prostacyclin D) nitric oxide E) oxygen

To produce angiotensin II, what must be secreted from the kidney to convert angiotensinogen to angiotensin I, which is then converted to angiotensin II by angiotensin converting enzyme? 18) A) renin B) angiotensinogen C) preangiotensin D) vitamin D3 E) erythropoietin

Which of the following is an important vasodilator in coronary arteries? 19) A) adenosine B) nitric oxide C) endothelin-1 D) oxygen E) bradykinin

What organ has capillaries that are the most restrictive to movement of hydrophilic solutes? 20) A) skeletal muscle B) kidneys C) brain D) liver E) bone marrow

Which of the following accurately describes sympathetic control of blood vessels in the skin during thermoregulation? 21) A) Heat causes a decrease in sympathetic activity, resulting in vasoconstriction. B) Heat causes an increase in sympathetic activity, resulting in vasodilation. C) Heat causes an increase in sympathetic activity, resulting in vasoconstriction. D) Heat causes a decrease in sympathetic activity, resulting in vasodilation. E) Heat activates the parasympathetic activity and has no effect on the sympathetic nervous system.

Information about mean arterial pressure is integrated within what area of the central nervous system? 22) A) cervical spinal cord B) hypothalamus C) cerebellum D) medulla oblongata E) pons

Which of the following can cause vasoconstriction? 23) A) increase in carbon dioxide B) increase in histamine C) increase in osmolarity D) release of nitric oxide E) angiotensin II

Nitric oxide has what effect on systemic arterioles? 24) A) vasoconstriction and vasospasm B) vasospasm C) vasoconstriction D) neither vasodilation or vasoconstriction, but may cause vasospasm E) vasodilation

Which of the following will NOT occur in response to a decrease in the extent of stretch detected by a baroreceptor? 25) A) increased ventricular contractility B) increased urine flow C) increased peripheral resistance D) increased venomotor tone E) increased heart rate

Valves, which are found ________, maintain the unidirectional movement of blood, thereby facilitating the return of blood to the heart. 26) A) only in central veins B) in all venules C) only in peripheral veins D) only in arteries E) in all veins

Which of the following is a decrease in tissue oxygen? 27) A) active hyperemia B) reactive hyperemia C) ischemia D) myogenic response E) hypoxia

The respiratory pump facilitates the return of blood to the heart by 28) A) raising the pressure gradient between abdominal and thoracic veins during inspiration. B) decreasing the pressure gradient between abdominal and thoracic veins during inspiration. C) squeezing blood from the rhythmic contraction of the diaphragm muscle. D) decreasing the pressure gradient between abdominal and thoracic veins during expiration. E) raising the pressure gradient between abdominal and thoracic veins during expiration

In the circulatory system, the largest pressure drop occurs across which blood vessels? 29) A) arteries B) veins C) capillaries D) arterioles E) venules

Hydrogen ions have what effect on systemic arterioles? 30) A) vasodilation B) neither vasodilation or vasoconstriction, but may cause vasospasm C) vasospasm D) vasoconstriction and vasospasm E) vasoconstriction

In response to a decrease in the stretch of a baroreceptor, sympathetic nervous activity will ________ while parasympathetic nervous activity will ________. 31) A) not change : increase B) decrease : increase C) increase : decrease D) not change : remain constant E) decrease : remain constant

The long-term regulation of arterial blood pressure involves the 32) A) release of hormones over a period of minutes. B) stimulation of an increase in urine flow through the kidneys. C) immediate change in activity of the nervous system. D) control of blood volume by the kidneys. E) control of peripheral resistance

Which of the following has high compliance, allowing it to hold a large volume of blood with little change in pressure? 33) A) vein B) arteriole C) artery D) capillary E) venule

34. What component of artery walls allows them to store energy that is later used to maintain continuous blood flow through the circulatory system? A) collagen B) smooth muscle C) elastin D) endothelium E) skeletal muscle

Which of the following chemicals' concentration is NOT increased by an elevation in metabolic activity? 35) A) carbon dioxide B) oxygen C) hydrogen D) potassium E) pyruvic acid

Due to their location, baroreceptors in the large systemic veins and the heart function primarily to monitor 36) A) blood flow. B) heart rate. C) total peripheral resistance. D) blood volume. E) mean arterial pressure.

Which of the following equations is correct? 37) A) resistance = (length × radius4) / viscosity B) cardiac output = stroke volume × heart rate C) mean arterial pressure = resistance × viscosity D) mean arterial pressure = cardiac output × stroke volume E) cardiac output = mean arterial pressure × total peripheral resistance

Which of the following substances is continuously secreted by endothelial cells and causes vasodilation? 38) A) endothelin-1 B) bradykinin C) oxygen D) nitric oxide E) adenosine

Which of the following descriptions of the autonomic innervation of the cardiovascular system is FALSE? 39) A) Both sympathetic and parasympathetic neurons innervate smooth muscle in arterioles. B) Only sympathetic neurons innervate smooth muscle in veins. C) Sympathetic activity increases cardiac output, whereas parasympathetic activity decreases cardiac output. D) Only sympathetic neurons provide significant innervation of the contractile cells of the heart. E) Both sympathetic and parasympathetic neurons innervate the SA node

Which of the following is a decrease in blood supply to the tissue such that it does not meet the metabolic demands of the tissue? 40) A) hypoxia B) active hyperemia C) myogenic response D) ischemia E) reactive hyperemia

A decrease in pressure within an arteriole will initiate a(n) 41) A) myogenic response. B) cardiac and venous baroreceptor reflex. C) arterial baroreceptor reflex. D) active hyperemia. E) sinus arrhythmia

Which of the following would NOT increase mean arterial pressure? 42) A) decreased parasympathetic activity effects on the heart B) increased sympathetic activity to the veins C) decreased parasympathetic activity effects on the arterioles D) increased sympathetic activity to the heart E) increased levels of epinephrine in the blood

Which of the following would decrease central venous pressure? 43) A) increased respiratory activity B) standing up C) activity of skeletal muscles D) increased blood volume E) increased sympathetic activi

Smooth muscle in the veins has what type of adrenergic receptor? 44) A) gamma B) alpha cholinergic C) alpha D) beta2 E) cholinergic

The reduction in organ blood flow that results from a decrease in mean arterial pressure would be exacerbated by the ________ that occurs as a consequence of the baroreceptor reflex. 45) A) increased stroke volume B) increased venous return C) decreased compliance of the veins D) increased ventricular contractility E) increased peripheral resistance

Under normal conditions, which Starling forces favor filtration? 46) A) capillary hydrostatic pressure and plasma oncotic pressure B) capillary hydrostatic pressure and interstitial fluid osmotic pressure C) interstitial fluid hydrostatic pressure and interstitial fluid osmotic pressure D) capillary hydrostatic pressure and interstitial fluid hydrostatic pressure E) interstitial fluid hydrostatic pressure and plasma oncotic pressure

Calculate the net filtration pressure given the following information: capillary blood pressure = 40 mm Hg; interstitial fluid hydrostatic pressure = 2 mm Hg; plasma osmotic pressure = 20 mm Hg; and interstitial fluid osmotic pressure = 5 mm Hg. Does filtration or absorption occur across this capillary wall? 47) A) 27 mm Hg; filtration B) 17 mm Hg; filtration C) 23 mm Hg; filtration D) 27 mm Hg; absorption E) 67 mm Hg; absorption

Which of the following is NOT a mechanism that alters the balance between filtration and absorption in the body? 48) A) increasing the permeability of the capillaries in regions of tissue damage B) increasing hydrostatic pressure gradient in cases of enhanced interstitial protein C) increasing the elimination of plasma proteins in cases of kidney damage D) decreasing plasma protein synthesis in cases of liver damage E) increasing capillary hydrostatic pressure within the feet as one stands

Despite seeming counterproductive, an increase in arterial carbon dioxide levels activates ________, which causes a(n) ________ in heart rate and a(n) ________ in total peripheral resistance. 49) A) chemoreceptors: decrease : decrease B) baroreceptors : decrease : decrease C) baroreceptors : decrease : increase D) baroreceptors : increase : increase E) chemoreceptors : decrease : increase

In cardiac and skeletal muscle vasculature, the distribution of alpha and beta receptors is such that epinephrine will 50) A) induce a dilation that increases blood flow to these tissues. B) increase skeletal muscle contractility. C) induce a constriction that decreases blood flow to these tissues. D) have no effect on peripheral resistance. E) increase myocardial contractility

Blood pressure is usually estimated from indirect measurements of the pressure in what structure? 51) A) left ventricle B) aorta C) femoral artery D) brachial artery E) radial artery

An increase in the stretch of a baroreceptor will cause venomotor tone to ________ while ventricular contractility will ________. 52) A) decrease : decrease B) increase : decrease C) increase : increase D) increase : not change E) remain constant : not change

The pulsatile nature of blood pressure is greatest in which blood vessels? 53) A) capillaries B) arteries C) venules D) arterioles E) vein

Parasympathetic nervous activity has what effect on systemic arterioles? 54) A) vasospasm B) vasoconstriction C) vasodilation D) neither vasodilation or vasoconstriction, but may cause vasospasm E) neither vasoconstriction and vasodilation

Angiotensin II has what effect on systemic arterioles? 55) A) vasospasm B) vasoconstriction and vasospasm C) vasoconstriction D) vasodilation E) neither vasodilation or vasoconstriction, but may cause vasospasm

Drugs that block angiotensin-converting enzyme would cause which of the following? 56) A) decreased heart rate B) activation of the parasympathetic nervous system C) decreased mean arterial pressure D) stimulation of reactive hyperemia E) decrease in epinephrine release

Bradykinin causes vasodilation by stimulating the release of what substance from endothelial cells? 57) A) thromboxane A2 B) nitric oxide C) cyclooxygenase D) arachidonic acid E) endothelin I

Of the following choices, which has the elastic recoil of its walls during diastole, causing a continuation of blood flow throughout the cardiac cycle? 58) A) artery B) venule C) vein D) capillary E) arteriole

Which of the following terms is used to label the rhythmic changes in sympathetic and parasympathetic activity that affect heart rate coincident with respiration? 59) A) pulmonary sinus arrhythmia B) respiratory sinus rhythmia C) respiratory sinus arrhythmia D) lung sinus rhythmia E) pulmonary sinus rhythmia

Veins functions as ________ reservoirs due to their ________ compliance. 60) A) pressure : high B) pressure : lack of C) volume : high D) pressure : low E) volume : low

Which of the following would cause relaxation of precapillary sphincters? 61) A) sympathetic activity B) vasopressin C) carbon dioxide D) epinephrine E) parasympathetic activity

Which of the following best classifies the baroreceptor reflex? 62) A) cranial; autonomic; innate; polysynaptic B) cranial; somatic; conditioned; polysynaptic C) cranial; autonomic; conditioned; monosynaptic D) spinal; autonomic; innate; polysynaptic E) spinal; autonomic; innate; monosynapti

The effects of epinephrine on vascular resistance are dependent upon which of the following? 63) A) relative distribution of alpha and beta receptors B) concentration of local metabolites C) direction of change in mean arterial pressure D) specific baroreceptor activated (low or high pressure) E) relative distribution of nicotinic and muscarinic receptors

The high compliance of veins allows them to 64) A) provide the driving force for the movement of blood through the vasculature during diastole. B) rapidly change central venous pressure with small changes in blood volume. C) act as pressure reservoirs. D) accommodate large volumes of blood with little change in pressure. E) hold only small volumes of blood.

Which of the following would increase the rate of blood flow through a blood vessel? 65) A) increased pressure of the blood entering the vessel B) decreased radius of the vessel C) increased length of the vessel D) increased viscosity of the blood E) constriction of the blood vessel

What are the two functions of increasing blood flow to the skin during exercise? 66) A) energy reserve for underlying musculature; provide energy for sweat production B) facilitate dissipation of heat; provide energy for sweat production C) facilitate dissipation of heat; remove water for sweat production D) fat utilization for energy production; remove water for sweat production E) facilitate dissipation of heat; energy reserve for underlying musculature

A person goes to the doctor and is told his blood pressure is 90/60 and his pulse is 80. Which of the following is FALSE? 67) A) Mean arterial pressure is 70 mm Hg. B) Diastolic pressure is 60. C) Systolic pressure is 90 mm Hg. D) Pulse pressure is 80 mm Hg. E) Heart rate is 80.

During exercise, which organs receive an increase in the proportion of cardiac output delivered to them? 68) A) gastrointestinal tract and skeletal muscle B) skeletal muscle, heart, and brain C) skeletal muscle, heart, and skin D) brain and heart E) skeletal muscle, skin, and brain

Which of the following would decrease mean arterial pressure? 69) A) increase in total peripheral resistance B) increase in arteriole diameter C) increase in heart rate D) increase in venous return E) increase in stroke volume

Which of the following is NOT altered within seconds to minutes of the baroreceptor reflex being activated? 70) A) venomotor tone B) total peripheral resistance C) stroke volume D) blood volume E) heart rate

In comparison to the systemic circuit, the pulmonary circuit 71) A) transports deoxygenated blood. B) has lower resistance to blood flow. C) has an equal pressure gradient to drive blood flow. D) has lower blood flow. E) is under greater pressure.

The primary mechanism for exchange of substances across the capillary wall is 72) A) bulk flow. B) vesicle transport. C) active transport. D) mediated transport. E) diffusion.

Where is the cardiovascular control center? 73) A) pons B) hypothalamus C) adrenal medulla D) adrenal cortex E) medulla oblongata

Which of the following would increase blood flow through a capillary bed? 74) A) contraction of precapillary sphincters in the capillary bed B) contraction of smooth muscle in the metarterioles bypassing the capillary bed C) constriction of the arteriole leading into the capillary bed D) decrease in blood pressure in the arteriole leading into the capillary bed E) increase in venous pressure

Which of the following does NOT occur in response to baroreceptors detecting an increase in mean arterial pressure? 75) A) vasoconstriction B) decreased frequency of sinoatrial node action potentials C) decreased heart rate D) decreased end-diastolic volume E) decreased venous compliance

Which of the following statements about smooth muscle in arterioles is FALSE? 76) A) The muscle is multi-unit smooth muscle. B) Muscle contraction is under intrinsic controls. C) Muscle contraction is under extrinsic controls. D) The muscle forms rings around the arteriole. E) The muscle has inherent (myogenic) tone

An increase in blood flow to tissues in response to increased metabolic activity is called 77) A) myogenic response. B) hypoxia. C) reactive hyperemia. D) ischemia. E) active hyperemia.

________ describes the movement of fluid out of the capillary, while ________ describes the movement of fluid into the capillary. 78) A) Venous pooling : edema B) Absorption : filtration C) Edema : venous pooling D) Hydrostatic pressure : oncotic pressure E) Filtration : absorption

Mean arterial pressure can be increased by all of the following EXCEPT 79) A) increasing heart rate. B) increasing sympathetic activity. C) increasing blood volume. D) decreasing end-diastolic volume. E) increasing venous return

________ are responsible for the detection of mean arterial pressure. 80) A) Thermoreceptors B) Medullary chemoreceptors C) Arterial baroreceptors D) Venous baroreceptors E) Aortic chemoreceptors

Epinephrine triggers vasodilation by binding to which receptors and vasoconstriction by binding to which receptors? 81) A) beta : cholinergic B) alpha1 : beta1 C) beta2 : alpha D) alpha2 : beta2 E) alpha : beta2

Which of the following substances is secreted by endothelial cells and causes vasoconstriction? 82) A) oxygen B) nitric oxide C) bradykinin D) adenosine E) endothelin-1

Which of the following is NOT a mechanism that enables molecules to move across capillary endothelial cells? 83) A) transcytosis across endothelial cells B) diffusion of lipid-soluble molecules directly across the endothelial cell C) rapid diffusion of water-soluble molecules directly across the endothelial cells D) movement through water-filled gaps between endothelial cells e) movment of exchangeable proteins across endothelial cells

What is the fluid within the lymphatic vessels called? 84) A) pus B) plasma C) filtrate D) lymph E) exudates

The portion of osmotic pressure exerted by ________ in the blood is known as colloid osmotic pressure (or oncotic pressure). 85) A) large ions B) steroids C) lipids D) proteins E) small ions

Which of the following accurately compares active hyperemia to reactive hyperemia? 86) A) One is caused by an increase in metabolites, the other to a decrease in perfusion pressure. B) One is an increase in blood flow, the other is a decrease. C) One is caused by increased metabolic activity, the other in response to an increase in metabolites from an occlusion to blood flow. D) One involves vasodilation, the other vasoconstriction. E) One is an intrinsic response, the other an extrinsic response

An increase in total peripheral resistance, in the absence of any change in cardiac output, would 87) A) reduce the stretch on the aorta. B) elevate mean arterial pressure. C) decrease pulmonary venous pressure. D) reduce mean arterial pressure. E) decrease central venous pressu

The increase in stroke volume that occurs during exercise is caused primarily by a(n) 88) A) increase in venous return. B) decrease in peripheral resistance. C) increase in end-diastolic volume. D) increase in myocardial contractility. E) decrease in end-systolic volume

Which of the following blood vessels is slightly larger than capillaries, allowing for some exchange between blood and the tissue? 89) A) artery B) vein C) capillary D) venule E) arteriole

An increase in blood flow to tissues in response to a previous reduction in blood flow is called 90) A) hypoxia. B) active hyperemia. C) myogenic response. D) reactive hyperemia. E) ischemia.

The increase in blood flow to active skeletal muscle relative to other organs is largely caused by the 91) A) decrease in parasympathetic activity. B) increase in local metabolic factors within the muscle. C) increase in sympathetic activity. D) decrease in metabolic factors within the muscle. E) increase in parasympathetic activity.

During exercise, carbon dioxide produced by muscle cells causes vasodilation in skeletal muscle. This is an example of 92) A) reactive hyperemia. B) hypoxia. C) ischemia. D) flow autoregulation. E) active hyperemia.

What is the driving force for blood flow through the systemic circuit? 93) A) right atrial pressure B) left ventricular pressure C) capillary hydrostatic pressure D) central venous pressure E) mean arterial pressure

Any change in the relative distribution of cardiac output to an organ is typically due to changes in which of the following? 94) A) mean arterial pressure B) compliance of that organ's vascular bed C) viscosity of the blood moving through that organ's D) central venous pressure E) resistance of that organ's vascular bed

Which of the following comparisons between systemic capillaries and lymphatic capillaries is TRUE? 95) A) Blood cells are found in both types of capillaries. B) Fluid enters systemic capillaries from systemic arterioles; fluid enters lymphatic capillaries from lymphatic veins. C) Pressure is higher in lymphatic capillaries. D) Walls of systemic capillaries are more permeable. E) Net filtration occurs across systemic capillaries; net absorption occurs across lymphatic capillaries.

Which of the following is the smallest of blood vessels with thin walls allowing for ready exchange of material between blood and tissue? 96) A) venule B) capillary C) vein D) arteriole E) artery

What is the driving force for blood flow through the systemic circuit? 97) A) perfusion pressure B) cardiac output C) mean arterial pressure D) total peripheral resistance E) pulse pressure

Which of the following is the equation relating cardiac output, mean arterial pressure, and total peripheral resistance? 98) A) MAP = CO × TPR B) TPR = CO/MAP C) MAP + CO + TPR = pulse pressure D) MAP = CO - TPR E) CO = TPR/MAP

Where are the arterial baroreceptors located? 99) A) coronary arteries B) brachiocephalic artery C) aortic arch and carotid sinuses (carotid arteries) D) coronary sinuses and aortic arch E) the pons

Which of the following can cause edema? 100) A) damage to capillary walls only B) decreased venous pressure only C) increase in extravasated plasma proteins only D) both an increase in plasma proteins and a decrease in venous pressure E) both damage to capillary walls and an increase in extravasated plasma proteins

What is a drop in mean arterial pressure that results from standing up called? 101) A) orthostatic hypotension B) metastatic hypotension C) paroxysmal hypotension D) resultant hypotension E) recumbent hypotension

What is a decrease in tissue oxygen called? 102) A) hypoxemia B) hyperemia C) ischemia D) hyperoxia E) hypoxia

What is bulk flow of fluid from inside a capillary into interstitial fluid called? 103) A) absorption B) excretion C) adsorption D) secretion E) filtration

In response to a decrease in tissue metabolic activity, tissue oxygen concentrations ________, which causes a(n) ________. 104) A) decrease : active hyperemic response B) increase : constriction of the arterioles C) decrease : increase in tissue ischemia D) increase : active hyperemic response E) decrease : dilation of the arterioles

Given the following information, calculate the net filtration pressure: capillary hydrostatic pressure = 30 mm Hg; interstitial fluid hydrostatic pressure = 5 mm Hg; capillary oncotic pressure = 25 mm Hg; and interstitial fluid oncotic pressure = 10 mm Hg. 105) A) 10 mm Hg, favoring filtration B) -40 mm Hg, favoring reabsorption C) 40 mm Hg, favoring filtration D) 0 mm Hg, no net force E) -10 mm Hg, favoring reabsorption

What is a measure of the change in vascular volume as pressure within the vessel is altered? 106) A) compliance B) the pressure gradient C) resistance D) diffusibility E) blood flow

What type of adrenergic receptor is found in the smooth muscle of most systemic arterioles? 107) A) alpha only B) beta1 only C) beta2 only D) beta3 only E) both alpha and beta1

The hormone vasopressin acts in the short term to ________ and in the long term to ________, thereby increasing mean arterial pressure. 108) A) vasodilate arterioles : decrease urine outflow B) vasoconstrict arterioles : decrease urine outflow C) decrease urine outflow : vasoconstrict arterioles D) increase urine outflow : vasodilate arterioles E) vasodilate arterioles : increase urine outflow

The blood vessels of largest diameter are the ________, and the blood vessels with the thickest walls are the ________. 109) A) veins : veins B) arteries : arterioles C) veins : arteries D) arteries : arteries E) arteries : veins

The elastic nature of the largest blood vessel's walls allows them to act as a ________, maintaining the driving force for blood flow while the heart is relaxed during diastole. 110) A) non-distensible structure B) pressure reservoir C) contractile force D) volume reservoir E) non-compliant structure

What is/are the component(s) of a blood vessel's extracellular matrix that provide(s) the tensile strength required to withstand pressure? 111) A) gap junctions B) elastin C) albumin D) collagen E) hemoglobin

What is a decrease in blood flow that is less than what is necessary to keep up with metabolic demands called? 112) A) hyperemia B) hypoxemia C) infarction D) ischemia E) hypoxia

Vasopressin has what effect on systemic arterioles? 113) A) vasospasm B) vasoconstriction and vasospasm C) vasoconstriction D) vasodilation E) neither vasodilation or vasoconstriction, but may cause vasospasm

As mean arterial pressure increases, the ________, informing the medulla oblongata that blood pressure has indeed increased. 114) A) frequency of action potentials from the baroreceptors increases B) number of neurons stimulated within the aortic arch increases C) amplitude of the action potentials from the baroreceptors increases D) blood flow to the brain increases E) number of sympathetic neurons activated decreases

Which of the following is NOT a component of the microcirculation? 115) A) metarterioles B) veins C) venules D) capillaries E) arterioles

During exercise, which of the following tissues receive less blood flow compared to resting conditions? 116) A) gastrointestinal tract only B) brain only C) skin only D) heart only E) both gastrointestinal tract and skin

The chronic elevation in arterial pressure (hypertension) that occurs in many individuals results in 117) A) the maintenance of a constant error signal by the baroreceptor. B) the resetting of the baroreceptor to a lower pressure. C) a decreased sensitivity of the baroreceptor that causes pressure to fluctuate. D) the baroreceptors becoming more sensitive to pressure. E) a gradual increase in pressure that resets the baroreceptors.

What is an increase in blood flow in response to an increase in tissue metabolic activity called? 118) A) active hyperemia B) hyperoxia C) reactive hyperemia D) ischemia E) hypoxia

Which of the following has the regulation of its radius determining blood flow through specific organs? 119) A) vein B) capillary C) artery D) arteriole E) venule

Given that the net filtration of fluid out of the capillaries averages about 3 liters per day, how is blood volume maintained in light of this apparent fluid loss? 120) A) Gravity moves the fluid to the lowest point in the body, where the fluid is absorbed. B) The kidneys are involved in the reabsorption of the remaining fluid. C) While fluid moves out across the capillary, it tends to move inward across veins. D) The lymphatic system returns filtered fluid to the blood. E) The net filtration is equally balanced by absorption.

Arteriolar smooth muscle in which of the following tissues tends to have beta2 receptors predominating? 121) A) brain B) skin C) skeletal muscle D) gastrointestinal tract E) liver

An increase in the volume of blood ejected from the heart, with no change in total peripheral resistance, would 122) A) elevate mean arterial pressure. B) reduce the stretch on the aorta. C) elevate central venous pressure. D) reduce mean arterial pressure. E) elevate pulmonary venous pressure

What structures of the cardiovascular system are innervated by the sympathetic nervous system, but are NOT by the parasympathetic nervous system? 123) A) SA node and AV node B) SA node, AV node, and bundle of His C) arteriolar smooth muscle D) arteriolar smooth muscle and venous smooth muscle E) ventricular myocardium, arteriolar smooth muscle and venous smooth muscle

At rest, the greatest proportion of blood volume is present within the 124) A) heart. B) pulmonary veins. C) systemic arteries. D) systemic veins. E) systemic capillaries.

Which of the following will NOT occur as a consequence of the activation of the baroreceptor reflex that would occur in response to an increased heat load within the body? 125) A) an increase in venoconstriction B) an increase in heart rate C) a decrease in resistance within the skeletal muscle vasculature D) an increase in stroke volume E) an increase in resistance within the skin vasculature

Sympathetic nerves have what effect on systemic arterioles? 126) A) vasodilation B) vasoconstriction C) vasospasm D) vasoconstriction and vasospasm E) neither vasodilation or vasoconstriction, but may cause vasospasm

What are local controls that tend to keep blood flow constant called? 127) A) autonomics B) flow autoregulation C) osteogenic factors D) extrinsic factors E) flow telemetry

The total cross-sectional area is greatest in which blood vessels? A) venules B) arteries C) arterioles D) veins E) capillaries

Carbon dioxide has what effect on systemic arterioles? 129) A) vasoconstriction B) vasodilation C) neither vasodilation or vasoconstriction, but may cause vasospasm D) vasoconstriction and vasospasm E) vasospasm

Foreign materials are filtered out of the lymphatic fluid by what type of cell located within the lymph nodes? 130) A) platelets B) leukocytes C) macrophages D) mast cells E) erythrocytes

Blood flow velocity is inversely proportional to the pooled surface area of a structure; therefore, it is greatest in the ________ and slowest in the ________. 131) A) capillaries : arteries B) arteries : capillaries C) veins : arteries D) arteries : veins E) arterioles : veins

Which of the following is an incorrect description of a blood vessel type? 132) A) Veins have high compliance. B) Most of the blood volume at rest is in the systemic veins. C) Arteries are elastic. D) The radius of arterioles can be regulated by both intrinsic and extrinsic controls. E) Capillary walls are comprised of only two cell layers, minimizing the distance for exchange.

Glucose moves across continuous capillary walls by what mechanism? 133) A) primary active transport B) transcytosis C) secondary active transport D) diffusion E) facilitated

What is the equation relating flow to resistance and a pressure gradient? 134) A) flow = pressure × resistance B) flow = pressure gradient / resistance C) flow/resistance = 1/pressure gradient D) flow × resistance = 1/pressure gradient E) flow × resistance = pressure × gradient