1) The segment of the systemic circulation in which each blood vessel has the

smallest diameter is:

a) aorta

b) arterioles

c) capillaries

d) venules

e) vena cava

2) The segment of the systemic circulation in which blood flow velocity is

highest is:

a) aorta

b) arterioles

c) capillaries

d) venules

e) vena cava

a) aorta

3) LaPlace’s Law states that:

a) P=T×r

b) r=P×T

c) T=P×r

d) T=1/r4

e) ΔP=F×R

c) T=P×r

4) In a particular blood vessel, decreasing radius by one-half does what to the

resistance to flow through this vessel?

a) Increase by a factor of 16

b) Increase by a factor of 4

c) Cannot be calculated from this information

d) Decrease by a factor of 4

e) Decrease by a factor of 16

a) Increase by a factor of 16

5) If right atrial pressure is held constant at 0 mm Hg and arterial blood pressure is increased from 90 mm Hg to 108 mm Hg, and if total peripheral

(systemic circulation) resistance is held constant, one could calculate that the cardiac output has done what?

a) Increased by 80%

b) Increased by 60%

c) Increased by 40%

d) Increased by 20%

e) Decreased by 40%

d) Increased by 20%

Answer: From Ohm’s Law, we know that ΔP=F×R. In this case, ΔP has increased by

20%, but resistance has not changed. Therefore, the cardiac output (F) must have

increased by 20%.

6) Vasoconstriction in the arterioles of the legs would be expected to;

a) Increase blood pressure

b) Decrease blood pressure

c) Increase blood flow in the legs

d) Decrease blood flow in the legs

e) Answers “a” and “d” are correct.

e) Answers “a” and “d” are correct.

7) When measuring blood pressure, you measure two pressures. Which is the

higher of the two pressures?

a) Systolic pressure

b) Mean pressure

c) Diastolic pressure

d) Pulse pressure

e) Examination pressure

a) Systolic pressure

8) The Bernoulli Principle states that:

a) Increased pressure increases velocity.

b) Increased velocity decreases pressure.

c) Decreased pressure decreases velocity.

d) Decreased velocity decreases pressure.

b) Increased velocity decreases pressure.

9) Find the statement about turbulence that is false:

a) Turbulent flow is noisy

b) Laminar flow is not turbulent

c) Turbulent flow is less efficient than laminar flow

d) Most of the flow in the cardiovascular system is turbulent

e) Reynolds Number can be used to predict turbulence

d) Most of the flow in the cardiovascular system is turbulent

10) Increases in which of the following variables tend to decrease resistance to blood flow?

a) Radius of the blood vessel

b) Viscosity of the blood

c) Length of the blood vessel

d) Blood hematocrit

e) Turbulent flow of the blood

a) Radius of the blood vessel

1) Increases in which of the following variables would be expected decrease venous return?

a. Cardiac output

b. Sympathetic nervous system tone

c. Blood volume

d. Venous resistance

e. Mean circulatory filling pressure

d. Venous resistance

2) Mean circulatory filling pressure is determined by:

a. Blood volume

b. Heart rate

c. Venous return

d. Cardiac output

e. Blood viscosity

a. Blood volume

MCF is P when no flow 

3) When comparing the standing position to the supine position:

a. Blood in the arteries of the toes flows backwards to the heart

b. Blood in the arteries of the toes has a higher pressure than in the aorta

c. Blood in the veins of the toes has a higher pressure than blood in the arteries of the toes

d. Blood tends to pool in the veins of the head and neck

e. There are no differences between standing and supine.

b. Blood in the arteries of the toes has a higher pressure than in the aorta

4) A “positive inotrope” is:

a. Anything that increases vascular constriction

b. Anything that increases blood volume

c. Anything that increases hematocrit

d. An agent that increases cardiac contractility

e. An agent that decreases heart rate

d. An agent that increases cardiac contractility

5) Transfusion:

a. Increases cardiac output

b. Increases venous return

c. Increases mean circulatory filling pressure

d. Increases blood volume

e. All of the above

e. All of the above

1) The name of the shunt that allows blood to flow from pulmonary artery to aorta is called the:

a. Ductus venosus

b. Umbilical vein

c. Foramen ovale

d. Ductus arteriosus

e. Cisterna magna

d. Ductus arteriosus

2) Among the stated fetal blood vessels, the partial pressure of oxygen is

highest in:

a. Femoral (leg) artery

b. Carotid (head) artery

c. Umbilical artery

d. Umbilical vein

e. Coronary venule

d. Umbilical vein

3) The compliance of the lungs is highest in the:

a. First breath of life

b. Second breath of life

c. Third breath of life

d. Fourth breath of life

e. Adult life

e. Adult life

4) The right and left ventricles of the fetus:

a. Pump equal amounts of blood per unit time

b. Together pump the “combined ventricular output”

c. Create different pressures in pulmonary artery and aorta

d. Are actually one cardiac chamber until after birth, when the interventricular septum forms

e. Perform equal amounts of work

b. Together pump the “combined ventricular output”

5) A red blood cell in the umbilical vein will first encounter which of the following shunts?

a. Ductus arteriosus

b. Ductus venosus

c. Foramen ovale

b. Ductus venosus

1) During a muscle contraction which region disappears?

a) I Band

b) A Band

c) Z Disk or Z line

d) H Zone

e) none of the above

ANS: D:

During muscle contraction the length of the filaments do not change length, only the amount of overlap between them changes. During a maximal contraction the I band decreases in size and the H Zone disappears.

2) Myosin is released from actin during the cross-bridge cycle by the:

a) release of Pi

b) release of ADP

c) acidosis

d) binding of ATP

e) A and B

ANS: D:

It is the binding of ATP that results in movement from the rigor state due to the release of myosin from actin

3) The primary role of calcium in skeletal and cardiac muscle is to:

a) cause depolarization of the sarcolemma

b) remove the inhibition of the reaction between actin and myosin

c) provide energy necessary for contraction

d) cause muscle relaxation

e) regulate ionic composition of the cell

ANS: B:

Under resting conditions skeletal muscle contraction is tonically inhibited by preventing myosin binding to actin, this inhibition is removed following Ca binding to TnC.

4) White muscle fibers

a) have characteristically high myoglobin levels

b) lack the enzymes necessary for anaerobic metabolism

c) are well supplied with capillaries

d) are fatigue resistant

e) fatigue relatively quickly

ANS: E:

White muscle fibers are characterized by the absence of mitochondria and myoglobin and hence are white in appearance. The low mitochondrial content renders this type of muscle fiber vulnerable to fatigue due to the inability to support the oxidative supply of ATP.

5) A muscle is capable of shortening with its maximal velocity when it is:

A. Shortest length.

B. Longest length.

C. Exposed to B-type natriuretic peptide.

D. Unloaded.

E. Maximally loaded.

6) Skeletal and cardiac muscle differ in all of the following except

a) size

b) t-tuble-SR connections

c) mitochondrial content

d) possess sarcomeres

e) None of the above

ANS: D:

Both skeletal and cardiac muscles are striated and possess sarcomeres.

7) The latch property of smooth muscle refers to the ability of the smooth muscle to maintain:

A. entirely relaxed state independent of free Ca++ levels

B. Maintaining force production while decreasing the rate of energy utilization

C. The rate of ATP production after stimulation

D. Force in the absence of myosin light-chain phosphorylation

E. A decreased membrane potential

ANS: B

The “latch” state is an unique property of smooth muscle is which muscle tone can be maintained while ATP utilization is decreasing

8) Duchenne Muscular dystrophy affects:

A. Young Girls

B. Postmenopausal women

C. Boys

D. In active males

E. The Elderly

ANS: C

Duchenne Muscular Dystrophy is an X-linked disease that affects newborn boys.

9. Which of the following will increase stroke volume?

A. Increased arterial pressure

B. Reduced activity of cardiac sympathetic nerves

C. Increased ventricular filling pressure

D. Low extracellular Ca2+

E. Reduced end-diastolic volume

10. During the cardiac cycle, which of the following occurs when left ventricular pressure rises above aortic pressure?

A. The mitral valve closes.

B. The aortic valve closes.

C. The mitral valve opens.

D. The aortic valve opens.

E. The pulmonary valve closes.

The answer is D. The aortic valve remains closed until left ventricular pressure exceeds aortic pressure, forcing the one-way valve open. When left ventricular pressure falls below aortic pressure, the one-way aortic valve closes. The mitral valve is positioned between the left atrium and left ventricle, and its opening and closing is regulated by the pressures in the left atrium and the left ventricle. The pulmonary valve is positioned between the right ventricle and the pulmonary artery.

11.

11. What lead primarily measures forces moving from the head to the feet?

A. Lead I

B. aVF

C. V1

D. V6

E. aVR

12. If two successive QRS complexes are 0.8 seconds apart:

A. Heart rate is 48 bpm.

B. Heart rate is 60 bpm.

C. Heart rate is 75 bpm.

D. Heart rate is 80 bpm

E. Heart rate is 86 bpm.

13. If a depolarizing electrical stimulus was applied to a ventricular myocyte, which of the following would be most likely to occur if extracellular calcium was low (below normal)?

A. the magnitude of Phase 0 of the action potential would increase

B. Phase 0 of the action potential would be eliminated

C. repolarization of the membrane would not occur, i.e., resting membrane potential would not be re-established

D. the duration of the plateau phase (Phase 2) of the action potential would increase

E. the duration of the plateau phase (Phase 2) of the action potential would decrease

The answer is E.

A and B are not correct because Phase 0 (the upstroke) results from an increase in Na+ permeability, not calcium permeability. C is not correct because membrane repolarization results from changes in potassium permeability. Low extracellular calcium would reduce (E) rather than increase the duration of the plateau.

14. Which of the following would be most likely to occur if the AV node was damaged by ischemia?

A. The ability to intrinsically increase heart rate during stress (such as exercise) would be impaired.

B. Conduction of the depolarizing electrical signal from the atria to the ventricles would be delayed or blocked.

C. Spreading of the depolarizing electrical signal from the septum to the ventricular walls would be impaired.

D. Cardiac contractility would be impaired.

E. Cardiac contractility would be increased.

The answer is B.

The AV node conducts the electrical signal from the SA node and the atria to the septum of the ventricle. If it is damaged, atrioventricular transmission is blocked or delayed. The ability to increase heart rate would remain intact, and cardiac contractility would not be affected by AV node damage.

15. Which of the following relations or laws fundamentally explains why aneurysms burst?

A. Ohm’s Law

B. Starling’s Law of the Heart

C. Pouiseille’s Relation

D. LaPlace’s Law

E. Murphy’s Law

16. Three tubes are arranged in parallel, as shown in the following illustration:

The resistance to flow in tube 1 is 100 mm Hg/(L/min), the resistance to flow in tube 2 is 50 mm Hg/(L/min), and the resistance to flow in tube 3 is 25 mm Hg/(L/min). The total resistance of these three tubes arranged in parallel is closest to which of the following choices?

A. .006 mm Hg/(L/min)

B. 14.3 mm Hg/(L/min)

C. 26.7 mm Hg/(L/min)

D. 58.3 mm Hg/(L/min)

E. 175 mm Hg/(L/min)

Answer: Rt-1=R1-1 + R2-1 + R3-1 +Rn-1. Therefore, Rt=(.01+.02+.04)-1

17. Which of the following, in the absence of changes in other variables, will tend to decrease venous return?

A. increased right atrial pressure

B. decreased venous compliance

C. increased blood volume

D. decreased venous resistance

E. increased mean circulatory filling pressure

18. Of the following sites within the fetal circulation, which has the highest oxygen saturation?

A. umbilical artery

B. umbilical vein

C. descending aorta

D. carotid artery

E. superior vena cava

19. In a normal healthy person an increase in cardiac output will decrease:

A. Venous return

B. Pulmonary vascular resistance

C. Pulmonary arterial pressure

D. Systemic arterial pressure

E. The size of zone 3 of the lung

20. Which of the following would be the most likely to cause pulmonary edema?

A. Hemorrhage

B. Increased oncotic pressure

C. Reduced capillary permeability

D. Pulmonary capillary recruitment

E. Left heart failure

21. Mean arterial pressure readings over 3 months are between 90 and 100 mmHg for patient X and between 150 and 160 for patient Y. A rapid decrease in carotid sinus pressure would:

A. Decrease both sympathetic and parasympathetic nerve activity only in patient X

B. Increase sympathetic and decrease parasympathetic nerve activity only in patient X

C. Decrease parasympathetic nerve activity about equally in both patients

D. Stimulate the chemoreceptor reflex in both patients

E. Increase plasma renin activity only in patient Y

22. Reduced firing of the atrial “B” receptors will:

A. Inhibit renin secretion

B. Increase activity in the Nucleus of the Solitary Tract

C. Increase heart rate

D. Increase vasopressin (AVP) secretion

E. Cause a reflex reduction in blood volume

23. Total spinal anesthesia reduces blood pressure because:

A. The arterial baroreceptor afferents are not functioning

B. Vasopressin secretion falls to zero

C. Parasympathetic nerve activity to the heart is eliminated

D. Sympathetic nerve activity to the vasculature and heart is eliminated

E. Activity in the arterial baroreceptor afferents is reduced

24. Nitric oxide:

A. is generated by endothelial cells

B. Is freely permeable to cell membranes

C. activates cyclic GMP in vascular smooth muscle cells

D. is a potent vasodilator

E. all of the above

25. In peripheral blood vessels, humoral agents:

A. stimulate only vasodilation because their action is confined to the endothelium.

B. stimulate both vasodilation and vasoconstriction depending upon receptor distribution within vascular cells

C. have little effect because they only act only on peripheral tissue, not on vascular cells.

D. stimulate the same vasoactive response in all organs

E. stimulate only vasoconstriction because they increase vascular smooth muscle calcium.

26. Large lipid-insoluble drugs cross the continuous capillary endothelium in the brain by:

A. Transcytosis

B. Bulk flow

C. Diffusion

D. Intercellular clefts

E. Lipid rafts

27. If hemorrhage causes precapillary resistance arterioles to constrict and capillary hydrostatic pressure decreases, which of the following is most likely to occur?

A. Net filtration of fluid from the capillaries will increase

B. Net absorption of fluid in the capillaries will increase

C. Net absoprtion of fluid in the capillaries will not change

D. Capillary diameter will decrease

E. Capillary diameter will increase

1. Isovolumetric contraction of the left ventricle:

a)   begins when the aortic valve opens and ends when the aortic valve closes

b)   begins when mitral valve closes and ends when the aortic valve opens

c)   requires less time (is shorter) than isovolumetric contraction of the right ventricle

d)   is not influenced by changes in aortic pressure

2.  According to Starling’s Law of the heart, an increase in end diastolic volume:

a)   results in greater shortening of the ventricular muscle

b)   increases stroke volume

c)   is proportional to the increase in the initial length of myocardial fibers in the left ventricle

d)   increases the net external work done by the heart

 e)   all of the above 

3.  If afterload on the ventricle increases:

a)      velocity of shortening in the ventricular muscle will increase

b)      pressure development during isovolumetric contraction will increase

c)      stroke volume will increase

d)      the pressure at which the aortic valve opens will be lower

e)      all of the above

4.  If both left ventricular end-diastolic volume and left ventricular end-diastolic pressure increase in a patient with a failing heart, then left atrial pressure will:

a)    increase

b)    decrease

c)    not change

1.  Ach, released by the Vagus nerve, reduces heart rate by:

a)   decreasing I_f ( funny) current

            b)   reducing Ca²⁺ current

c)   reducing K⁺ current causing resting membrane potential to move towards threshold

            d)   both A and B

            e)   all of the above

2.  Repolarization of ventricular myocytes (Phase 3) occurs mainly due to:

a)    activation of L-type calcium channels

b)    influx of K⁺

c)    efflux of K⁺

d)    influx of Na⁺

e)    efflux of Na⁺

1.    Which of the following components of the ECG would be most likely to be altered by an area of cardiac ischemia that is interfering with ventricular repolarization?

a)      the P-wave

b)      the PR interval

c)      the RR interval

d)      the T wave

1.    If the ECG tracing shows that the QRS is isoelectric in Lead I and the net deflection of the QRS in aVF is positive, e.g. +2, then the mean electrical axis of the heart must be approximately:

a)    90 degrees

b)    60 degrees

c)    0 degrees

d)    110 degrees

In the tracings below, if the QRS in Lead III is considered to be isoelectric, what is the mean electrical axis of the heart?

           a)      90 degrees

b)      120 degrees

c)      30 degrees

d)      60 degrees

1.    An increase in the R-R interval on the ECG indicates:

            a)   an increase in heart rate

b)   a decrease in heart rate

c)   an increase in atrial contraction

d)   a decrease in atrial contraction

1. What is typically required for contraction of cardiac muscle?

A. Ca++ influx through voltage-gated Ca++ channels to trigger a rise in cytosolic [Ca++].

B. Ca++ influx through voltage-gated Ca++ channels, which is sufficient to support contraction.

C. Activation of MLCK.

D. Phosphorylation of myosin heavy chain.

E. Ca++ influx through the Na+-Ca++ antiporter.

2. What is typically required for relaxation of cardiac muscle?

A. Myosin light-chain dephosphorylation.

B. Activation of the ryanodine receptor.

C. Ca++ uptake by the SR (sarcoplasmic reticulum).

D. Phosphorylation of phospholamban.

E. Activation of the dihydropyridine receptor.

1. When a pregnant uterus presses on the abdominal vena cava, which of the following occurs? Make comparisons relative to conditions before the maneuver.

a) right atrial pressure increases and arterial pressure increases.

b) right atrial pressure increases and arterial pressure decreases.

c) right atrial pressure decreases and arterial pressure increases.

d) right atrial pressure decreases and arterial pressure decreases.

e) no changes in either right atrial or arterial pressures.

1. An increase in systemic blood pressure from 100 to 120 mm Hg would be expected to have what effect on the renal circulation of a normal individual?

a) increased vascular resistance and little change in blood flow.

b) increased vascular resistance and modestly decreased blood flow.

c) decreased vascular resistance and modestly increased blood flow.

d) decreased vascular resistance and modestly decreased blood flow.

e) no changes in either resistance or blood flow.

2. In a given patient, mean aortic pressure is 105 mm Hg, right atrial pressure is 5 mm Hg, heart rate is 75 beats per minute, and stroke volume is 80 ml. The total peripheral resistance in this individual is closest to:

a) 2 mm Hg per (L/min)

b) 17 mm Hg per (L/min)

c) 6 mm Hg per (L/min)

d) 60 (ml/min) per mm Hg

e) 8 mm Hg per (min/L)

3. One resistance vessel in the microvasculature decreases in diameter from 100 to 70. What happens to the resistance through this vessel?

a) decreases by a factor of 4.16

b) decreases by a factor of 2.25

c) increases by a factor of 0.06

d) increases by a factor of 2.25

e) increases by a factor of 4.16

4. In a normal individual:

a) total blood flow (liters/min) is lower in the capillaries than in the aorta.

b) blood flow velocity (m/sec) is lower in the capillaries than in the aorta.

c) blood pressure (mm Hg) is higher in the capillaries than in the aorta.

d) colloid oncotic pressure (mm Hg) is higher in the capillaries than in the aorta.

e) resistance to blood flow is the same in individual capillaries as in the aorta.

5. What are the only two changes which can increase mean circulatory filling pressure?

a) increased venous compliance and increased blood volume.

b) increased venous compliance and decreased blood volume.

c) decreased venous compliance and increased blood volume.

d) decreased venous compliance and decreased blood volume.

e) neither venous compliance nor blood volume affect mean circulatory filling pressure.

6. When I lay supine in a warm tub of water, which of the following is true?

a) arterial pressure in my toes is higher than arterial pressure in my aorta.

b) venous pressure in my toes is higher than arterial pressure in my toes.

c) venous pressure near the right atrium is lower than venous pressure in my toes.

d) arterial pressure in my brain is higher than arterial pressure in my aorta.

e) venous pressure in my neck is higher than arterial pressure in my aorta.

Total

5000

Blood Flow (mL/min)

7. What is the value of this individual’s total peripheral resistance?

a) 21 mm Hg per (L/min)

b) 20 mm Hg per (L/min)

c) 19 mm Hg per (L/min)

d) .0526 (L/min) per mm Hg

e) .050 (L/min) per mm Hg

8. Which tissue in the table has the highest resistance to blood flow?

a) Liver

b) Kidneys

c) Brain

d) Bone

e) Adrenal Glands

e) Adrenal Glands

lowest blood flow

1. Which of the following would be most likely to lead to pulmonary edema?

a) Decreased plasma protein synthesis (e.g. in liver failure)

b) Pulmonary vasodilation

c) Right heart failure

d) Hemorrhage

e) Exercise

2. When is resistance to pulmonary blood flow the highest?

a) At total lung capacity

b) During pulmonary vasodilation

c) At functional residual capacity

d) While breathing air at high altitude

e) During aerobic exercise

1. Select the order of components involved in the arterial baroreflex response to an increase in blood pressure:

a) Baroreceptor afferents, CVLM, NTS, RVLM, parasympathetic efferents to the vasculature

b) Baroreceptor efferents, RVLM, NTS, CVLM, sympathetic afferents to the vasculature

c) Baroreceptor afferents, NTS, CVLM, RVLM, sympathetic efferents to the vasculature

d) Baroreceptor efferents, NTS, CVLM, RVLM, sympathetic afferents to the vasculature

e) Baroreceptor afferents, NTS, RVLM, CVLM sympathetic efferents to the vasculature

2. Why is the relationship between blood pressure and heart rate a sigmoid function (select all that apply)?

a) Individual baroreceptor afferents have different threshold pressures

b) Heart rate is controlled by both the sympathetic and parasympathetic nervous systems

c) There is a maximum total firing rate for all baroreceptor afferents

d) The caudal ventral lateral medulla has inhibitory neurons

e) The carotid bodies are near the carotid baroreceptors

3. When blood pressure is increased, stimulation of the baroreceptor reflex rapidly (within a minute) reduces blood pressure because:

a) Vasopressin secretion is inhibited

b) Venous capacitance is reduced

c) Vasopressin secretion is increased

d) The caudal ventral lateral medulla has inhibitory neurons

e) Parasympathetic nerve activity to the heart and vasculature is reduced.

1. A tissue that autoregulates:

a) lacks sympathetic innervation

b) maintains relatively constant blood flow over a range of perfusion pressures

c) does not demonstrate metabolic vasodilation

d) has minimal metabolic demands

2. A decrease in vessel radius from 10 cm to 5 cm increases the resistance to blood flow through that vessel by:

a) 4 times

b) 2 times

c) 8 times

d) 16 times

e) 32 times

3. If transmural pressure in a blood vessel rises from 4x104 dyn/cm2 to 5x104 dyn/cm2, and the vessel constricts reducing radius from 100 m to 80 m, wall stress will:

a) double

b) remain constant

c) decrease by half

d) decrease by ten-fold

1. In peripheral blood vessels, humoral agents:

a) stimulate only vasodilation because their action is confined to the endothelium

b) stimulate both vasodilation and vasoconstriction depending upon receptor distribution within vascular cells

c) have little effect because they only act only on peripheral tissue, not on vascular cells

d) stimulate the same vasoactive response in all organs

e) stimulate only vasoconstriction because they increase vascular smooth muscle calcium

2. In most vascular beds, sympathetic nerves elicit vasoconstriction of blood vessels by:

a) lowering blood pressure

b) release of norepinephrine from post-ganglionic fibers and binding to α-adrenergic receptors

c) activation of endothelin binding to ET-B receptors

d) activating pain receptors which stimulates release of tissue metabolites

3. Many humoral agents cause smooth muscle vasoconstriction by:

a) increasing influx of extracellular calcium

b) reducing influx of extracellular calcium

c) increasing influx of extracellular sodium

d) blocking phosphorylation of myosin light chain kinase

1. If capillary hydrostatic pressure is 30 mmHg, capillary osmotic pressure is 25 mm Hg, and interstitial osmotic pressure is 3 mm Hg, which of the following describes fluid movement across the wall of the capillary?

a) no movement occurs

b) net filtration

c) net absorption

d) movement of fluid occurs only through vesicular transport

2. Which of the following blood vessels is not surrounded by smooth muscle cells?

a) Veins

b) Arteries

c) Arterioles

d) Terminal arterioles

e) Capillaries

3. During a bout of vigorous exercise, nearly all of the capillaries in contracting skeletal muscle become perfused with blood. This causes:

a) an increase in the permeability of oxygen

b) an increase in the surface area available for exchange of oxygen

c) an increase in oxygen extraction

d) both b and c

e) all of the above