Chapter 14 Quiz

If someone's heart has a stroke volume of 70 ml and a heart rate of 90 beats/min, the cardiac output equals _____________. a. 6.3 L/min b. 0.77 L/min c. 70 ml/min d. 1.28 ml/min

a. 6.3 L/min

___________ is a polypeptide vasodilator produced by the sweat glands. a. Bradykinin b. Histamine c. Seratonin d. Endorphin

a. Bradykinin

Low blood pressure stimulates the secretion of the Mineralocorticoid ______________. a. aldosterone b. angiotensin II c. vasopressin (ADH) d. atrial natriuretic peptide (ANP)

a. aldosterone

Veins are said to have a higher ____ than arteries because they expand more easily and a higher ___________ because they contain more blood. a. compliance; capacitance b. compliance; capacitance c. elasticity; capacitance d. elasticity; compliance

a. compliance; capacitance Feedback: Veins have thinner, less muscular walls than do arteries therefore at a given amount of pressure will cause more expansion in veins than arteries (compliance) so the veins can hold more blood (capacitance).

According to the Frank-Starling law of the heart, the strength of ventricular contraction is a. directly proportional to the end-diastolic volume. b. inversely proportional to the end-diastolic volume. c. independent of the end-diastolic volume.

a. directly proportional to the end-diastolic volume.

If a vessel were to dilate to twice its previous radius, and if pressure remained constant, blood flow through this vessel would a. increase by factor of 16 b. increase by a factor o 4 c. increase by a factor of 2 d. decrease by a factor of 2

a. increase by factor of 16

The SA node depolarizes more frequently under the influence of ____________. a. norepinephrine b. acetylcholine c. the vagus nerve d. the medulla oblongata

a. norepinephrine

The enzyme that converts angiotensinogen into angiotensin II is _____________. a. renin b. angiotensin-converting enzyme (ACE) c. atrial natriuretic peptide (ANP d. vasopressin (ADH)

a. renin

Cardiac control centers in the medulla oblongata receive input from baroreceptors located in some of the arteries. a. true b. false

a. true

Cerebral blood flow remains fairly constant at about 750 ml/min, in spite of changes in brain activity, blood pressure, and blood flow to other organs. a. true b. false

a. true

In spite of the fact that the systemic vessels cover substantially more total length than the pulmonary vessels, the same amount of blood must flow through both of these systems at a given time. a. true b. false

a. true

Stroke volume is directly proportional to end-diastolic volume. a. true b. false

a. true

Decreased osmolality of the blood leads to decreased secretion of ADH. a. true b. false

a. true Feedback: Dilution of the blood (as in drinking excessive amounts of water) decreases the plasma osmolality and inhibits the release of ADH.

Which of these statements about atriovenous shunts in the skin is true? a. They divert blood to superficial capillary loops b. They are closed when the ambient temperature is very low c. They are closed when the deep-body temperature rises above 37 degrees Celsius d. All of these are true

b. They are closed when the ambient temperature is very low

According to the classic view of the Starling forces, capillaries usually tend to absorb fluid ________________. a. at the arteriolar end b. at the venular end c. only when the precapillary sphincters are open d. at neither end; they filter fluid and it is up to the lymphatic vessels to absorb it

b. at the venular end

Stroke volume is regulated by all of the following except ____________. a. end-diastolic volume b. cardiac output c. contraction strength d. mean arterial pressure

b. cardiac output

Any mechanism that increases heart rate is said to have a positive ______ effect. a. feedback b. chronotropic c. inotropic d. cholinergic

b. chronotropic Feedback: Mechanisms that affect cardiac rate are said to have a chronotropic effect (chrono = time). Those that increase cardiac rate have a positive chronotropic effect while those that decrease cardiac rate have a negative chronotropic effect.

The contractility of heart muscle is its _______________. a. contraction strength at any length b. contraction strength at any given fiber length c. contraction frequency, which determines heart rate d. ability to contract, which is restored after the refractory period

b. contraction strength at any given fiber length

The heart's contractility is adjusted so that normally each ventricle expels all the blood contained in it, leaving none behind in the chamber. a. true b. false

b. false

Since the veins contain most of the body's blood at any one time, they have a higher blood pressure than any other type of vessel. a. true b. false

b. false Feedback: Although veins contain almost 70% of the total blood volume, the mean venous pressure is only 2mmHg therefore they have the lowest pressure than any type of vessel.

The net filtration pressure of the capillaries is equal to the hydrostatic pressure of tissue fluid outside the capillaries. a. true b. false

b. false Feedback: If these two values were equal, there would be no filtration, therefore, net filtration pressure is equal to the hydrostatic pressure of the blood in the capillaries minus the hydrostatic pressure of tissue fluid outside the capillaries, which opposes filtration.

All parasympathetic nerve fibers to the heart innervate the SA node. a. true b. false

b. false Feedback: Parasympathetic nerve fibers innervate the AV node as well as the SA node.

The arteries that supply blood to the organs are generally in a series with each other than in parallel with each other. a. true b. false

b. false Feedback: The arteries that supply blood to the organs are generally in parallel, that is, arterial blood passes through only one set of arterioles before returning to the heart.

All of the fluid filtered by the capillaries of the kidneys is ultimately excreted as urine. a. true b. false

b. false Feedback: The percent of the glomerular filtrate reabsorbed and thus the urine volume and blood volume is adjusted according to the needs of the body.

Both ADH and aldosterone act to a. Increase urine volume b. increase blood volume c. increase total peripheral resistance d. produce all of these effects

b. increase blood volume

Blood flow in the coronary circulation a. increases during systole b. increases during diastole c. remain constant throughout the cardiac cycle

b. increases during diastole

During systole, the ventricular myocardium gets its oxygen supply mainly from _______. a. hemoglobin b. myoglobin c. its high density of blood capillaries d. its high density of mitochondria

b. myoglobin

Stretch receptors in the aortic arch and carotid sinus a. stimulate secretion of atrial natriuretic peptide b. serve as barorecpetors that affect activity of the vagus and sympathetic nerves c. serve as osmoreceptors that stimulate the release of ADH d. stimulate renin secretion, thus increasing angiotensin II formation

b. serve as barorecpetors that affect activity of the vagus and sympathetic nerves

The Frank-Starling law of the heart describes the relationship between ___________. a. stroke volume and cardiac output b. stroke volume, end-diastolic volume, and contraction strength c. stroke volume and total peripheral resistance d. the left and right ventricles

b. stroke volume, end-diastolic volume, and contraction strength

Cardiac output may drop when one goes from lying to a standing position because of ________________. a. the baroreceptor reflex b. venous pooling c. orthostatic hypertension d. sinus tachycardia

b. venous pooling

Of all the factors that can affect blood flow to a particular organ, the most effective and easiest to control from moment to moment is _____________. a. blood viscosity b. vessel radius c. vessel length d. pressure differential

b. vessel radius

Contraction of the left ventricle of the heart at rest normally expels about ______ of the blood contained in the chamber. a. 10(--)15% b. 25(--)33% c. 60(--)70% d. 98(--)100%

c. 60(--)70%

Edema could be caused by all of the following except ______________. a. high arterial blood pressure (hypertension) b. leakage of plasma proteins into the tissue fluid, as in inflammation and allergy c. an elevated level of albumin in the blood plasma d. an obstruction of the lymphatic drainage

c. an elevated level of albumin in the blood plasma

The greatest resistance to blood flow occurs in a. large arteries b. medium-size arteries c. arterioles d. capillaries

c. arterioles

Intrinsic control of blood flow refers to the ________________. a. way in which blood flow is determined by cardiac output b. blood flow in all places other than the heart itself c. control of blood flow by metabolic products of the tissues d. control of blood flow by the nervous and endocrine systems

c. control of blood flow by metabolic products of the tissues

Arteriovenous anastomoses are found mainly in the ___________________. a. renal circulation b. mesenteries of the abdominal cavity c. dermis of the skin d. cerebral circulation

c. dermis of the skin

The preload acting on a ventricle is equivalent to that chamber's _____________. a. contractility b. stroke volume c. end-diastolic volume d. ejection fraction

c. end-diastolic volume

A positive inotropic agent is something that _______________. a. reduces the heart rate in a positive feedback loop b. increases the heart rate in a positive feedback loop c. increases the contractility of myocardial fibers d. decreases the contractility of myocardial fibers

c. increases the contractility of myocardial fibers Feedback: An increase in the amount of Ca2+ available to the sarcomeres due to an increase in epinephrine increases the strength of myocardial contraction

Blood flow in the cerebral circulation a. varies with systemic arterial pressure b. is regulated primarily by the sympathetic system c. is maintained constant within physiological limits d. increases during exercise

c. is maintained constant within physiological limits

Which of these statements about tissue fluid is false? a. it contains the same glucose and salt concentration as plasma b. it contains a lower protein concentration than plasma c. its colloid osmotic pressure is greater than that of plasma d. its hydrostatic pressure is lower than that of plasma

c. its colloid osmotic pressure is greater than that of plasma

Myxedema is a disease caused by hypothyroidism, which causes production of excessive amounts of glycoprotein in the Interstitial spaces. The effect of this on capillary fluid dynamics would be to cause ________________. a. precapillary sphincters to shut off blood flow to affected tissues b. vasodilation of the capillaries c. reduced osmotic return of fluid and thus accumulation of fluid in the tissues resulting in edema d. increased transfer of tissue fluid into the blood stream, resulting in hypertension

c. reduced osmotic return of fluid and thus accumulation of fluid in the tissues resulting in edema

A severe infection could decrease blood pressure by causing _____________. a. cardiogenic shock b. anaphylactic shock c. septic shock d. hypovolemic shock

c. septic shock Feedback: Septic shock is caused by an endotoxin produced by bacteria that decreases blood pressure and affects of ability of the heart to pump. Cardiogenic shock is due to cardiac failure. Anaphylactic shock is due to a severe allergy in which histamine is released causing systemic vasodilation. Hypovolemic shock is due to blood loss.

The pulse pressure Is a measure of a. the number of heartbeats per minute b. the sum of diastolic and systolic pressures c. the difference between systolic and diastolic pressures d. the difference between the arterial and venous pressures

c. the difference between systolic and diastolic pressures

During fight or flight reaction, the sympathetic nervous system causes vasodilation in skeletal muscle but vasoconstriction in the skin. It is able to achieve these opposite effects because ___________________. a. sympathetic fibers secrete epinephrine in the muscle and acetylcholine in the skin b. bradykinin stimulates constriction of arterioles in the dermis c. the muscles have cholinergic sympathetic fibers and the skin has adrenergic fibers d. the muscle arterioles have a-adrenergic receptors and the skin arterioles have §-adrenergic receptors

c. the muscles have cholinergic sympathetic fibers and the skin has adrenergic fibers

The volume of blood pumped per minute by the left ventricle is a. greater than the volume pumped by the right ventricle b. less than the volume pumped by the right ventricle c. the same as the volume pumped by the right ventricle d. either less or greater than the volume pumped by the right ventricle, depending on strength of contraction

c. the same as the volume pumped by the right ventricle

The sounds of Kortokoff are produced by a. closing of the semilunar valves b. closing of the AV valves c. the turbulent flow of blood through an artery d. elastic recoil of the aorta

c. the turbulent flow of blood through an artery

Which of these is a paracrine regulator that stimulates vasoconstriction? a. Nitric oxide b. Prostacyclin c. Bradykinin d. Endothelin-1

d. Endothelin-1

Which of these organs is able to tolerate the greatest reduction in blood flow? a. Brain b. Heart c. Skeletal Muscles d. Skin

d. Skin

An increase in blood volume will cause a. a decrease in ADH secretion b. an increase in Na excretion in the urine c. a decrease in renin secretion d. all of these

d. all of these

Baroreceptors are specialized pressure receptors found in the ____________. a. vena cava b. descending aorta c. medulla oblongata d. aortic arch

d. aortic arch

In the absence of compensations, the stroke volume will decrease when a. blood volume increases. b. venous return increases. c. contractility increases. d. arterial blood pressure increases.

d. arterial blood pressure increases.

The amount of blood pumped by each ventricle in one minute is called _____________. a. stroke volume b. end-diastolic volume c. ejection fraction d. cardiac output

d. cardiac output

Angiotensin II a. stimulates vasoconstriction b. stimulates the adrenal cortex to secrete aldosterone c. inhibits the action of bradykinin d. does all of these

d. does all of these

Atrial natriuretic peptide (ANP) helps to lower blood pressure and is secreted by the _____________. a. hypothalamus b. kidneys c. adrenal cortex d. heart

d. heart

During exercise, the cardiac output may rise to five times the resting value. In most people this is due mainly to an increase in ______________. a. stroke volume b. ejection fraction c. end-diastolic volume d. heart rate

d. heart rate

Osmoreceptors regulating the release of ADH are found in the _______________. a. kidneys b. right atrium of the heart c. aortic arch and carotid sinuses d. hypothalamus

d. hypothalamus Feedback: The hypothalamus functions as the thirst center and when osmoreceptors are stimulated, a person becomes thirsty and there is an increase in the amount of ADH released by the posterior pituitary.

Pulmonary edema, shortness of breath, and fatigue are most likely to result from _________________. a. cardiogenic shock b. anaphylactic shock c. right-sided congestive heart failure d. left-sided congestive heart failure

d. left-sided congestive heart failure

A sphygmomanometer is used for __________. a. correcting orthostatic blood pressure b. reducing tachycardia c. restoring blood volume d. measuring blood pressure

d. measuring blood pressure

Vasodilation in the heart and skeletal muscles during exercise is primarily due to the affects of a. alpha-adrenergic stimulation b. beta-adrenergic stimulation c. cholinergic stimulation d. products released by the exercising muscle cells

d. products released by the exercising muscle cells

Production of angiotensin II indirectly ____________. a. causes vasodilation of arterioles and muscular arteries b. inhibits the sense of thirst c. stimulates excretion of excess sodium by the kidneys d. raises the blood volume

d. raises the blood volume Feedback: Angiotensin II indirectly raises blood volume by stimulating thirst centers and stimulating secretion of aldosterone causing more salt and water to be retained by the kidneys.

The hydrostatic pressure of blood in a capillary is 19 mmHg and that of the tissue fluid is 1 mmHg, while the colloid osmotic pressure of the blood is 23 mmHg and that of the tissue fluid is 0 mm Hg, at this particular portion of the capillary, fluid is being _______ with a net force of __________. a. given off; 5 mmHg b. given off; -3 mmHg c. taken up; 3 mmHg d. taken up; -5 mmHg

d. taken up; -5 mmHg

Edema may be caused by a. high blood pressure b. decreased plasma protein concentration c. leakage of plasma protein into the interstitial fluid d. blockage of lymphatic vessels e. all of these

e. all of these

Blood pressure Is lowest in a. arteries b. arterioles c. capillaries d. venules e. veins

e. veins

If a person has an arterial blood pressure of 102/62, the mean arterial pressure would equal 82mmHg. a. true b. false

false