Deck 12: Cardiovascular Physiology

Question 1

You have a patient who has pernicious anemia.Which of the following supplements should she take to improve her symptoms?

A)Iron
B)Vitamin B₁₂
C)Vitamin E
D)Vitamin D
E)Bilirubin

Answer 1

B

Question 2

You are learning to read electrocardiograms.You know that the patient you are examining has a pathology affecting the depolarization of his ventricles,therefore you're looking for a change in what portion of his EKG?

A)The P wave
B)The T wave
C)The QRS complex
D)"The P wave" or "The T wave" but not "The QRS complex".
E)None of these would be altered

Answer 2

C

Question 3

Elizabeth had heart surgery to repair the pacemaker of her heart.Into which structure did the surgeon need access?

A)Sinoatrial node
B)Atrioventricular node
C)Mitral valve
D)Bundle of His
E)Left ventricle

Answer 3

A

Question 4

Which of the following statements concerning the differences between action potentials in skeletal muscle cells and in ventricular cardiac muscle cells is TRUE?

A)Like skeletal muscle cells,ventricular cardiac muscle cells have a resting membrane potential closer to the sodium equilibrium potential than to the potassium equilibrium potential.
B)Unlike skeletal muscle cells,the initial depolarization of ventricular cells is mainly due to calcium influx,not sodium influx.
C)After sodium influx through voltage-gated channels occurs in ventricular cells,prolonged influx of calcium from the extracellular fluid occurs.No such calcium influx occurs in skeletal muscle cells.
D)Action potentials in skeletal muscle cells are longer in duration than action potentials in cardiac muscle cells.
E)The efflux of K⁺ repolarizes skeletal muscle cells after an action potential,while repolarization in cardiac muscle cells is due to the efflux of Ca²⁺. 

Question 5

You are a synthetic chemist and have created a compound that appears to bind to acetylcholine receptors.When applied to the inside of the right atrium,what will the affect be?

A)Increased force of atrial contraction
B)Decreased force of atrial contraction
C)Decreased heart rate
D)Increased heart rate
E)No effects on heart function

Question 6

Which is TRUE about the condition anemia?

A)It can be caused by too little iron in the diet.
B)It can be caused by kidney failure.
C)It can be caused by abnormal hemoglobin.
D)It results in reduced oxygen-carrying capacity of the blood.
E)All of the answers are true.

Question 7

You and your lab partner are doing an experiment in physiology lab.Each of you has an isolated muscle cell and you are supposed to stimulate it with an electrode as soon as its absolute refractory period ends.You're watching an electromyograph tracing to know when to use the electrode.Your partner has a cardiac muscle cell and you have a skeletal muscle cell.Which one of you will use your electrode more times in one minute?

A)Your partner will use the electrode more times in a minute than you will.
B)You will use the electrode more times in a minute than your partner will.
C)You both will use the electrode the same number of times.
D)The number of times you will use the electrode in a minute cannot be determined by this information alone.

Question 8

Consider the equation F = ΔP/R.It describes the flow (F)of fluid in a tube in which there is a pressure difference (ΔP)between the two ends and a resistance (R)to flow.Based on this equation,which is a correct conclusion? 8-15-2013

A)The flow of fluid in a tube depends upon the absolute pressure at the beginning of the tube.
B)The rate of fluid flow in a tube will increase if the pressure at the beginning is increased while the pressure at the end of the tube stays the same.
C)The greater the resistance to flow in a tube,the greater the rate of flow for any given pressure difference.
D)If both the resistance and the pressure gradient in a tube increase,the flow must also increase.
E)The rate of flow in a tube will decrease if the resistance to flow is decreased.

Question 9

Action potentials in the heart spread from cell to cell through

A)desmosomes.
B)gap junctions.
C)interneurons.
D)valves.
E)coronary vessels.

Question 10

Which of the following would be most likely to be determined with a patient's ECG recording?

A)A heart murmur
B)Stroke volume
C)Cardiac output
D)Blockage of conduction of electrical signals between the atria and the ventricles
E)A leaky atrioventricular valve

Question 11

The plateau of the action potential in cardiac ventricular cells results from the opening of voltage-gated long-lasting ________ channels in the plasma membrane of the cell.

A)Na⁺
B)K⁺
C)Ca²⁺
D)Cl⁻
E)glucose

Question 12

What is the term that describes the production of red blood cells?

A)Hemaglutination
B)Erythrocytosis
C)Erythropoiesis
D)Erythroblastosis
E)Hemostasis

Question 13

Which is TRUE about the comparison of excitation-contraction coupling in cardiac muscle with that in skeletal muscle?

A)Extracellular Ca²⁺ plays a major role in cardiac but not skeletal muscle.
B)The mechanism  for Ca²⁺ release from the sarcoplasmic reticulum is the same in both types of muscle.
C)Troponin sites are completely saturated immediately after Ca²⁺ release in both types of muscle.
D)There is no net change in total intracellular Ca²⁺ concentration in either muscle.
E)Intracellular Ca²⁺ stores are necessary for contraction in skeletal muscle,but not in cardiac muscle.

Question 14

Which of the following statements about membrane potentials in different types of cardiac cells is TRUE?

A)Myocardial cells have a resting membrane potential of about -90 mV;pacemaker cells do not have a true resting membrane potential.
B)Once threshold depolarization is reached in both myocardial and pacemaker cells,the rapid upswing of the action potential is caused by the opening of voltage-gated Na⁺ channels
C)Voltage-gated transient (T-type) Ca²⁺ channels are present in all of the different types of cells of the heart.
D)There are no L-type Ca²⁺ channels in cardiac muscle cells.
E)The upstroke of the action potential is steeper in SA node cells than it is in Purkinje cells.

Question 15

Which is correct about the contraction sequence of the heart?

A)The contraction and relaxation of all four chambers happen at the same time.
B)The right atrium and ventricle contract at the same time,and as they are relaxing,the left atrium and left ventricle begin to contract.
C)Contraction begins in the order: right atrium,then right ventricle,then left atrium,then left ventricle.
D)The two atria contract at the same time,and as they are relaxing,the two ventricles contract together.
E)The atria and ventricles begin their contractions at the exact same time,but the atrial contraction only lasts half as long as the ventricle contraction.

Question 16

A male patient complains of physical weakness and fatigue.A blood test shows his hematocrit to be 30%.Which of the following diagnoses is the least likely to explain his symptoms?

A)Internal bleeding
B)Dietary iron deficiency
C)Dietary vitamin B₁₂ deficiency
D)Lung disease
E)Kidney disease

Question 17

A female has a blood test.One mL of her blood is drawn,spun in a centrifuge,and the plasma volume is measured and found to be 0.6 mL.Two months later the same patient returns to the doctor and,after doing another blood test,the doctor tells the patient that she has become anemic compared to her previous visit.Which of the following is most likely to be the woman's hematocrit on the second visit?

A)35%
B)50%
C)70%
D)100%
E)0.6 mL

Question 18

Which of the following changes would most increase the resistance to blood flow in a blood vessel?

A)Halving the diameter of the vessel
B)Doubling the diameter of the vessel
C)Halving the length of the vessel
D)Doubling the length of the vessel
E)Decreasing the hematocrit from 50% to 40%

Question 19

Where is most of the iron in a person's body located?

A)In the bone marrow
B)In the liver
C)In the cytochromes
D)In erythrocytes
E)In the kidneys

Question 20

Which of the following is NOT primarily a function of blood plasma?

A)Transport of hormones
B)Being in osmotic balance with red blood cells
C)Having plasma proteins that exert an osmotic pressure favoring fluid absorption into the capillaries
D)Providing clotting factors that are ready to be activated
E)Transport of oxygen

Question 21

Which of the following statements concerning control of blood flow through arterioles is TRUE?

A)Beta-adrenergic receptors are more abundant on most arteriolar smooth muscle than are alpha-adrenergic receptors.
B)Binding of epinephrine to alpha-adrenergic receptors causes vasodilation.
C)Increased stimulation of vascular smooth muscle by the parasympathetic nervous system causes increased vasoconstriction.
D)If the arterial blood pressure to an organ suddenly decreases,arterioles in the organ will dilate in response.
E)Body-wide constriction of arterioles results in a decrease in the total peripheral resistance (TPR).

Question 22

You and your colleague are medical technicians in a cardiac function lab.You are reading the ECG of a patient and your friend is trying to capture an image of the AV valves opening using an ultrasound.At what point should you tell your friend to start recording images?

A)Just before the P wave
B)Just after the P wave
C)At the beginning of the QRS complex
D)Just before the T wave
E)After the T wave

Question 23

Which of the following statements about the cardiac cycle is TRUE?

A)The duration of systole is greater than that of diastole in a subject at rest.
B)During isovolumetric ventricular relaxation,blood flows from the atria into the ventricles.
C)Closure of the atrioventricular valves occurs at the beginning of ventricular systole.
D)The QRS complex occurs at approximately the same time as the closure of the semilunar valves.
E)The first valves to go from closed to open after the atrial kick are the atrioventricular valves.

Question 24

In a patient with an abnormally leaky aortic valve,what would you expect?

A)Some backflow of blood into the aorta during ventricular diastole
B)Some backflow of blood into the left ventricle during ventricular diastole
C)Some backflow of blood into the left ventricle during ventricular ejection
D)Some backflow of blood into the aorta during ventricular ejection
E)Some backflow of blood into the left atrium during ventricular systole

Question 25

During the cardiac cycle of an individual at rest

A)the volume of blood leaving the left side of the heart is greater than that leaving the right side.
B)the pressure of blood leaving the right ventricle is greater than that leaving the left ventricle.
C)the duration of systole is greater than that of diastole.
D)the duration of diastole is greater than that of systole.
E)the contraction of the atria overlaps in time with the ventricular systole.

Question 26

Which of the following statements about the refractory period of neuronal or muscle membranes is TRUE?

A)In nerve cells,the absolute refractory period coincides with the period of increased K⁺ permeability.
B)In skeletal muscle cells,the absolute refractory period lasts about as long as the twitch.
C)In ventricular cells,the absolute refractory period coincides with the period of increased Na⁺ and Ca²⁺ permeability.
D)The relative refractory period in neuronal membranes lasts about the same length of time as the absolute refractory period in cardiac muscle cell membranes.
E)The refractory period in an alpha-motor neuron membrane is much briefer than the refractory period in a skeletal muscle cell membrane.

Question 27

What is described by the Frank-Starling mechanism of the heart?

A)The relationship between end-diastolic volume and heart rate
B)The relationship between end-systolic volume and stroke volume
C)The relationship between length and tension in cardiac muscle cells
D)The relationship between sympathetic stimulation and stroke volume
E)The relationship between arterial blood pressure and stroke volume

Question 28

Which of the following statements concerning regulation of blood flow is TRUE?

A)In the systemic circuit,increased levels of metabolic waste products and decreased oxygen concentration in tissues promote hyperemia through the tissues.
B)If blood flow to a tissue is blocked for a period of time and then the block is removed,the result is a reactive hyperemia in which blood flow through the affected tissue remains low.
C)According to flow autoregulation,if blood pressure to an arteriole is decreased,blood flow will not return toward its original level until the original blood pressure is restored.
D)In the systemic circuit,high levels of CO₂ and metabolites tend to cause contraction in the smooth muscle of arteriole walls.
E)The resistance to blood flow in brain and heart vascular beds does not vary in response to changes in local gas or metabolite concentrations.

Question 29

You've just been told by your doctor that you have a heart murmur between the first and second heart sounds.You go home to search for more information on this condition on the Internet and find that you have

A)insufficiency of a semilunar valve or stenosis of an AV valve.
B)insufficiency of an AV valve or stenosis of a semilunar valve.
C)heart failure.
D)AV nodal conduction block.
E)a myocardial infarction.

Question 30

Which is TRUE regarding the regulation of heart rate?

A)Stimulation of parasympathetic nerves to the heart causes a slowing of heart rate.
B)Stimulation of sympathetic nerves to the heart causes an increase in heart rate.
C)A person whose heart lacks autonomic innervation has a faster heart rate at rest than a person with a normally innervated heart.
D)The slope of diastolic depolarization in SA node cell action potentials determines the heart rate.
E)All of the choices are true.

Question 31

Blood flow through most organs in the systemic circuit is regulated primarily by increasing or decreasing the ________ activity to arteriolar smooth muscles in the organ.Another form of regulation,called ________,depends upon the metabolic activity of the organ.Increased activity leads to increased interstitial fluid metabolites,which cause ________ of the arterioles.The former is a type of ________ regulation of blood flow;the latter is an example of ________ regulation.

A)sympathetic;active hyperemia;dilation;extrinsic;intrinsic
B)sympathetic;reactive hyperemia;dilation;intrinsic;extrinsic
C)parasympathetic;active hyperemia;constriction;extrinsic;intrinsic
D)sympathetic;flow autoregulation;constriction;intrinsic;extrinsic
E)parasympathetic;reactive hyperemia;dilation;extrinsic;intrinsic

Question 32

Which occurs during isovolumetric ventricular contraction?

A)Rapid filling of the ventricles occurs.
B)No blood enters or leaves the ventricles.
C)The maximum volume of blood is ejected.
D)Ventricular pressure reaches its maximum value of the cardiac cycle.
E)The pressure in the ventricles decreases while the pressure in the atria increases.

Question 33

What causes the opening and closing of the heart valves?

A)Stimulation by the sympathetic and parasympathetic nerves
B)A pressure difference on the two sides of the valve
C)Na⁺ and K⁺ fluxes during ventricular depolarization
D)Turbulent flow in the atria and ventricles
E)The action of the papillary muscles and chordae tendineae

Question 34

According to the Frank-Starling mechanism of the heart

A)the left ventricle ejects a larger volume of blood with each systole than the right ventricle.
B)the intrinsic rate of the heart's pacemaker is 100 beats/min.
C)cardiac output increases with increased heart rate.
D)stroke volume increases with increased venous return.
E)both ventricles contract simultaneously.

Question 35

You are dissecting a species of amphibian that has just been discovered in the rainforest.You find a blood vessel where the blood travels at a low pressure and velocity.If the frog is in an upright position,blood flow through this vessel would also be against gravity.Anatomically,what do you expect of this blood vessel?

A)A high degree of compliance
B)A thick muscular wall
C)Large wall to lumen ratio
D)Valves that allow only one-way flow of blood
E)All of the answers are correct

Question 36

In the systemic circuit,which of these best describes active hyperemia?

A)Increased metabolic activity that results in vasoconstriction
B)Increased metabolic activity that results in vasodilation
C)Decreased blood flow to tissues that results in vasoconstriction
D)Decreased blood flow to tissues that results in vasodilation
E)Increased blood pressure that drives blood more rapidly through tissues

Question 37

Which best defines cardiac output?

A)The end-diastolic volume minus the end-systolic volume
B)The output of the aortic arch baroreceptors
C)The volume of blood in the arterial tree at any moment in time
D)The stroke volume divided by the heart rate
E)The product of the heart rate and the volume ejected from the ventricle during a cardiac cycle

Question 38

You've been sitting cross-legged on the floor of your dorm room while studying.As you stand up to go get a snack,you realize that you've lost feeling in one of your feet.A minute later,all feeling is restored.Being a physiology student,you understand that blood flow was occluded during the time that you were sitting,and that blood flow was restored as you stood up.What else is TRUE?

A)The decreased oxygen content of the foot tissues and the increased levels of metabolic wastes both acted as vasodilators,increasing the flow of blood through the tissues upon standing.
B)As you stood,vasoconstriction occurred in the foot's blood vessels to protect them from shock.
C)High levels of built up CO₂ acted as vasoconstrictors in the foot's blood vessels.
D)The resistance of the blood vessels did not change from sitting to standing,but gravity helped in blood flow.
E)All of these are true.

Question 39

Sinoatrial node cells

A)reach threshold only when action potentials generated by the AV node arrive through gap junctions.
B)exhibit spontaneous depolarization that is speeded by activation of their cholinergic receptors.
C)exhibit spontaneous depolarization that is speeded by activation of their beta-adrenergic receptors.
D)exhibit a steep upstroke due to the presence of the same type of Na⁺ channels found in neuronal membranes. 
E)are between atrial muscle cells and cells of the bundle of His.

Question 40

During the course of a ride on a roller coaster,what would be FALSE regarding your heart?

A)An increase in heart rate
B)A decrease in the duration of systole
C)A decrease in the slope of the pacemaker potential
D)An increase in the amount of Ca²⁺ entering cardiac muscle cells
E)An increase in the rate of cross-bridge cycling in ventricular muscle cells

Question 41

Which of the following is a result of increased sympathetic stimulation of vascular smooth muscle?

A)Filtration of fluid from capillaries to interstitial fluid increases.
B)Total peripheral resistance (TPR) decreases.
C)The percentage of blood volume in the veins increases.
D)Blood flow to the brain decreases.
E)Venous return of blood to the heart increases.

Question 42

Which of the following correctly compares the factors involved in bulk flow of fluid in systemic and pulmonary capillaries?

A)The protein oncotic pressure inside pulmonary capillaries is significantly greater.
B)There are no lymphatic vessels to remove fluid from lung interstitial fluid.
C)The hydrostatic pressure inside pulmonary capillaries is significantly lower.
D)The protein oncotic pressure is lower in pulmonary interstitial fluid than in typical systemic interstitial fluid.
E)The Starling's forces overwhelmingly favor reabsorption all along the length of pulmonary capillaries.

Question 43

A patient comes in to your office with dramatically high blood pressure.Which of the following symptoms might turn up in your exam?

A)Tissue swelling due to increased fluid leaving the capillaries
B)Skin bruising due to blood leaving the capillaries
C)Rapid breathing due to increased need for oxygen
D)Lethargy
E)None of these

Question 44

You have a patient who is showing signs of edema (tissue swelling)all over his body.In addition to visible swelling in his hands,feet,and face,you can also see evidence of swelling around his organs when viewing his CAT scan images.Thinking about what you know about the factors that regulate fluid flow from the blood vessels.Which of the following causes of edema seem most likely?

A)Low red and white blood cell counts due to cancer in the bone marrow
B)Low plasma protein concentration due to liver failure
C)High blood solute concentration due to kidney failure
D)Low blood pressure due to severe dehydration

Question 45

What determines the movement of blood in systemic veins?

A)The blood pressure difference between systemic capillaries and the right atrium
B)The contraction and relaxation of skeletal muscles
C)The decrease of thoracic pressure and increase of abdominal pressure due to diaphragm movement
D)Valves in the veins
E)All of the these

Question 46

After a long fever Carl finds himself sweating profusely.He ends up requiring several changes of clothing before his skin begins to dry off.After this sweating event,what can we expect of Carl's physiological state?

A)An increase in blood volume
B)Hypotension
C)Decreased firing of the arterial baroreceptors
D)Increased stroke volume
E)All of these

Question 47

Tina is a hard-working sales clerk in a busy department store.She has stood completely still behind the check-out counter for an 8-hour shift.At the end of Tina's shift she finds that she feels somewhat dizzy and guesses that her blood pressure is quite low.All of the following factors normally contribute to homeostatic blood pressure regulation.Which one is most likely contributing to her symptoms?

A)Decreased skeletal muscle pump
B)Increased activity of the pulmonary pump
C)Defective baroreceptor detection in the carotid artery
D)Increased sympathetic tone
E)All of these

Question 48

If the arterial blood pressure in the brain is suddenly decreased,the flow through arterioles in the brain will immediately fall and then which of these will occur next?

A)Brain arterioles will constrict to accelerate blood flow through the brain capillaries.
B)Brain arterioles will dilate due to a decrease in levels of CO₂.
C)Blood flow will remain at the new,lower level due to reactive hyperemia.
D)Blood flow will rise to levels above normal due to excess O₂ levels.
E)Blood flow will return toward its original level due to flow autoregulation.

Question 49

Sarah is resting in a chair for a long period of time;her calf and thigh muscles are totally relaxed.Next to her,Priya is also resting in a chair,but she is wiggling,kicking,tapping,and vibrating her legs;resulting in an pattern where her calf and thigh muscles are alternating between relaxed and contracted states.If all else is equal,who has the higher stroke volume,Sarah or Priya?

A)Sarah has a higher stroke volume.
B)Priya has a higher stroke volume.
C)Sarah and Priya have the same stroke volume because they are both seated.
D)No significant difference in the stroke volume between Sarah and Priya can be predicted based on this information.

Question 50

Jane donates a pint of blood to a blood bank.A few minutes later,which of the following would be increased compared to pre-donation values?

A)Heart rate
B)Stroke volume
C)Mean arterial pressure
D)Cardiac output
E)Hydrostatic pressure in the capillaries

Question 51

Sally has had too many alcoholic drinks.Alcohol is a systemic vasodilator and it increases urine volume,thereby decreasing blood volume.In order to maintain cardiac output,what can her body do?

A)Decrease heart rate
B)Increase heart rate
C)Increase stroke volume
D)Decrease stroke volume
E)Increase total peripheral resistance (TPR)

Question 52

Normally,the hydrostatic pressure difference between capillary fluid and interstitial fluid favors movement of fluid ________ a tissue capillary.The protein osmotic pressure difference between capillary fluid and interstitial fluid normally favors movement of fluid ________ a tissue capillary.

A)into;into
B)into;out of
C)out of;out of
D)out of;into

Question 53

Jane donates a pint of blood to a blood bank.A few minutes later,which of the following would be decreased compared to pre-donation values?

A)Her stroke volume and total peripheral resistance
B)Her heart rate and total peripheral resistance
C)Her heart rate and mean arterial pressure
D)The percentage of her cardiac output flowing to her kidneys
E)Blood flow to her brain

Question 54

In a patient with decreased production of plasma proteins,which of the following would be TRUE?

A)More fluid than usual will flow out of the capillary based on the osmotic pressure.
B)Less fluid than usual will flow out of the capillary based on the osmotic pressure.
C)More fluid than usual will flow out of the capillary based on the hydrostatic pressure.
D)Less fluid than usual will flow out of the capillary based on the hydrostatic pressure.

Question 55

Tina is a hard-working sales clerk in a busy department store.She has stood completely still behind the check-out counter for an 8-hour shift.At the end of Tina's shift,she finds that she feels somewhat dizzy and guesses that her blood pressure is quite low.When Tina gets home she also notices that her ankles are swollen.What physiological issue is most likely to blame in this scenario?

A)Lymphatic blockage in her lower legs
B)High osmotic pressure in her lower leg capillaries
C)High hydrostatic pressure in lower leg capillaries
D)Reactive hyperemia to lower leg tissues
E)None of these,the swelling is unrelated to cardiovascular issues

Question 56

Following hemorrhage,reflexes are triggered that attempt to compensate for the blood loss.As a result of the blood loss and the reflex mechanisms,which of the following will be TRUE,compared to pre-hemorrhage values?

A)Both cardiac output and total peripheral resistance will be increased.
B)Both cardiac output and total peripheral resistance will be decreased.
C)Cardiac output will be increased and total peripheral resistance will be decreased.
D)Cardiac output will be decreased and total peripheral resistance will be increased.
E)Hematocrit will be increased.

Question 57

Which of the following factors would NOT tend to increase systemic arterial blood pressure?

A)Increased sympathetic stimulation
B)Increased blood volume
C)Increased venous return
D)Increased parasympathetic stimulation
E)Increased activity of the skeletal muscle pump

Question 58

Jane donates a pint of blood to a blood bank.A few minutes later,which of the following would be increased compared to pre-donation values?

A)Her stroke volume and total peripheral resistance
B)Her heart rate and total peripheral resistance
C)Her heart rate and mean arterial pressure
D)The percentage of her cardiac output flowing to her kidneys
E)The blood flow to her brain

Question 59

Distinguishing characteristics of veins include which of the following?

A)All veins carry deoxygenated blood.
B)All veins carry blood toward the heart.
C)All veins have thick,elastic walls.
D)Veins have walls consisting only of endothelial cells.
E)All veins have valves to ensure one-way movement of blood.

Question 60

Which of the following statements concerning the capillaries is FALSE?

A)Increasing capillary hydrostatic pressure decreases the likelihood that filtration will occur.
B)Velocity of blood flow is slower in the capillaries than in the arteries.
C)It is possible for a capillary to filter fluid at its arterial end and absorb fluid at its venous end.
D)Large capillary pores are more likely to be found in liver capillaries than in brain capillaries.
E)Large proteins that escape capillaries and enter the interstitial fluid are returned to the circulation via the lymphatic system.

Question 61

During exercise,there is a decreased flow of blood to

A)the brain.
B)the skin.
C)the abdominal organs.
D)the skeletal muscles
E)the heart.

Question 62

Which of the drug treatments listed below is INCORRECTLY matched to a mode of action in treating hypertension?

A)Alpha-adrenergic receptor blockers-reduce TPR by decreased stimulation of arteriolar smooth muscle
B)Beta-adrenergic receptor antagonists-reduce cardiac output by slowing heart rate and reducing contractility
C)Antagonists of parasympathetic receptors-reduce TPR by decreased stimulation of arteriolar smooth muscle
D)Angiotensin-converting enzyme (ACE)inhibitors-reduce TPR by reducing angiotensin II concentrations
E)Diuretics-reduce blood volume by increasing excretion of sodium and water in urine
F)Calcium channel blockers-reduce speed and force of contraction in vascular smooth muscle
G)ACE inhibitors-lowers peripheral resistance by promoting vasodilation

Question 63

Which is the most likely effect of physical endurance training on a person's cardiac performance?

A)A decrease in cardiac output
B)An increase in maximal stroke volume
C)An increase in maximal heart rate
D)An increase in resting heart rate
E)An increase in cardiac output when the person is at rest

Question 64

Which of the following statements regarding blood clotting is TRUE?

A)Blood clotting requires activation of thrombin.
B)Blood clotting is enhanced by prostaglandin I₂ (PGI₂)and nitric oxide.
C)A blood clot is a network of interlacing strands of fibrinogen.
D)Blood clotting occurs too rapidly in individuals with the disease hemophilia.
E)Injecting tissue plasminogen activator (t-PA)into a patient who is bleeding will aid blood clotting.

Question 65

Arterial systolic pressure occurs ________ while arterial diastolic pressure occurs ________.

A)at the same time as closure of the semilunar valves;at the same time as closure of the atrioventricular valves 
B)during the isovolumetric contraction phase of the cardiac cycle;during the isovolumetric relaxation phase of the cardiac cycle
C)at the same time as the P-wave of the electrocardiogram;at the same time as the T-wave of the electrocardiogram
D)when the ventricle reaches end-systolic volume;when the ventricle reaches end-diastolic volume
E)during the middle of the phase of ventricular ejection;just before the semilunar valve opens

Question 66

Which of the following statements regarding the dissolving of blood clots is FALSE?

A)Activation of the reactions that lead to blood clotting ultimately lead to blood clot dissolution.
B)Tissue plasminogen activator (t-PA)is secreted by endothelial cells.
C)Blood clots are digested by plasmin.
D)Plasminogen is an inactive precursor of the enzyme plasmin.
E)It involves aggregation of soluble fibrin fragments into fibrin.

Question 67

Which of the following drugs might be prescribed to alleviate hypertension?

A)Alpha-adrenergic receptor agonists
B)Beta-adrenergic receptor antagonists
C)Cholinergic antagonist
D)A drug that increases L-type Ca²⁺ channel currents
E)A drug that increases T-type Ca²⁺ channel currents

Question 68

Which of the following is most likely to occur when a soldier stands at attention-very still,with legs and spine straight? 

A)Decreased pressure in the capillaries of the feet
B)Increased absorption of interstitial fluid by the capillaries of the feet
C)Increased storage of blood in the veins of the feet and legs
D)Increased venous return
E)Increased blood flow to the brain

Question 69

You just ate a huge,delicious breakfast and now are going to head out for your morning run.As you try picking up the pace,you find running to be quite difficult because

A)blood flow to the abdominal organs is dominant.
B)stroke volume is decreased.
C)everywhere in the systemic circuit,blood vessels are constricted.
D)your heart rate is too high.
E)your mean arterial pressure is too high.

Question 70

Which of the following does NOT contribute to increased stroke volume during exercise?

A)Increased contractility of cardiac muscle
B)Increased venous return
C)Increased length of filling time during diastole
D)Increased sympathetic stimulation of ventricular muscle
E)Increased end-diastolic volume

Question 71

Which of the following does NOT describe hypertension? Hypertension

A)refers to a chronic state of elevated blood pressure.
B)is usually defined as a systolic pressure greater than 140 mmHg and a diastolic pressure greater than 90 mmHg.
C)is usually a result of chronically elevated cardiac output.
D)may be caused by kidney disease.
E)can sometimes be treated with drugs that increase excretion of water in the urine.

Question 72

Platelets participate in hemostasis by

A)aggregating to form a plug and manufacturing fibrinogen.
B)secreting nitric oxide and releasing chemicals that promote vasoconstriction.
C)secreting prostacyclin,which prevents platelet aggregation on blood vessel endothelium.
D)aggregating to form a plug and releasing chemicals that promote vasoconstriction.
E)secreting tissue plasminogen activator (t-PA)whenever they come into contact with collagen.

Question 73

Which of these correctly states differences between a trained athlete and a sedentary individual at rest? 

A)The athlete would have a lower heart rate and larger stroke volume.
B)The athlete would have a higher heart rate and larger stroke volume.
C)The athlete would have a lower heart rate and smaller stroke volume.
D)The athlete would have a higher heart rate and smaller stroke volume.
E)There would be no differences when the individuals were at rest.

Question 74

Which is an intermediary protein that enables platelets to adhere to collagen?

A)Tissue plasminogen activator (t-PA)
B)ATP
C)von Willebrand factor (vWF)
D)Arachidonic acid
E)Activated protein C

Question 75

What is hemostasis?

A)The maintenance of relatively stable conditions in the internal environment
B)The prevention or stoppage of blood loss
C)A disease in which blood clot formation is impaired
D)A protein inside red blood cells that binds oxygen with high affinity
E)The set point for normal arterial blood pressure

Question 76

Which of the following occurs first in hemostasis?

A)Activation of the fibrinolytic system
B)Platelet aggregation
C)A clotting cascade that leads to the conversion of fibrinogen to stable fibrin
D)Conversion of prothrombin to thrombin
E)Conversion of plasminogen to plasmin

Question 77

In a patient with a mutation that causes an inactive von Willebrand factor (vWF),which of the following would be TRUE?

A)Platelets will not adhere to collagen.
B)Fibrinogen cannot polymerize.
C)Thrombin will never be activated.
D)Clots will be stronger than typical.
E)None of the answers will be true.

Question 78

How would a hemorrhage immediately affect the activity of the baroreceptors?

A)The baroreceptors would increase their rate of firing to all medullary cardiovascular center cell types.
B)The baroreceptors would increase their rate of firing to cells in the medulla oblongata that activate sympathetic pathways and decrease their rate of firing to cells in the medulla oblongata that activate parasympathetic pathways.
C)The baroreceptors would decrease their rate of firing to all medullary cardiovascular center cell types.
D)The baroreceptors would decrease their rate of firing to cells in the medulla oblongata that activate sympathetic pathways and increase their rate of firing to cells in the medulla oblongata that activate parasympathetic pathways.
E)A hemorrhage would not affect the activity of the baroreceptors.

Question 79

Which of the following statements about blood clotting is FALSE?

A)It is the formation of a thrombus.
B)It occurs after formation of a platelet plug in a damaged vessel.
C)It requires the presence of erythrocytes.
D)It is a result of a cascade of enzyme activation.
E)It involves positive feedback by thrombin.

Question 80

Atherosclerosis is

A)the major cause of heart attacks.
B)a thinning in the walls of arteries.
C)associated with low blood levels of cholesterol and heavy exercise.
D)a disease in which the walls of arteries become more compliant.
E)more common in younger people than in older people.