BY 32 – Fall 2000

Sections 6142/6143

 EXAM 3

NAME __________________________________

Instructions:  Record your answers directly on this sheet by circling the correct response.  For each question, choose the single best response.

 1.  The period during which the heart is actively contracting is referred to as: (A)

a.      systole.

b.     diastole.

c.      diastosis.

d.     stenosis.

 

2.  Oxygenated blood returning from the lungs passes first to which heart chamber? (C)

a.      Right atrium

b.     Right ventricle

c.      Left atrium

d.     Left ventricle

 

3.  Deoxygenated blood returning to the heart from the head and arms in the superior vena cava passes first to which heart chamber? (A)

a.      Right atrium

b.     Right ventricle

c.      Left atrium

d.     Left ventricle

 

4.  The pericardial cavity is located between the: (D)

a.      epicardium and myocardium.

b.     endocardium and myocardium.

c.      fibrous and serous layers of the pericardium.

d.     visceral and parietal layers of the serous pericardium.

 

5.  Of the various layers of the heart which of the following is lined by a layer of endothelium? (A)

a.      Endocardium

b.     Myocardium

c.      Epicardium

d.     All of the above

 

6.  Within the atria of the heart, the rough walled portion of the atrial wall is formed by structures called: (C)

a.      trabeculae carnae.

b.     chordae tendinae.

c.      pectinate muscles.

d.     valve cusps.

 

7.  Within the ventricles of the heart, the structures which attach to papillary muscles and the tips of atrioventricular valve cusps are called: (B)

a.      trabeculae carnae.

b.     chordae tendinae.

c.      pectinate muscles.

d.     auricles.

 

8.  The mitral (bicuspid) valve is open when: (D)

a.      right atrial pressure exceeds left atrial pressure.

b.     right atrial pressure exceeds right ventricular pressure.

c.      left atrial pressure exceeds right atrial pressure.

d.     left atrial pressure exceeds left ventricular pressure.

 

9.  The right atrium and left atrium are separated from one another by a structure called the: (B)

a.      intercalated disc.

b.     interatrial septum.

c.      interventricular septum.

d.     atrioventricular sulcus.

 

10.  The aortic semilunar valve is open during: (A)

a.      the ejection phase of left ventricular contraction.

b.     atrial systole.

c.      isovolumetric contraction of the left ventricle.

d.     both a and c.

 

11.  Which of the following represent functions of the fibrous skeleton of the heart? (B)

a.      Generating action potentials

b.     Providing the origin for valve cusps

c.      Conducting action potentials

d.     All of the above

 

12.  The coronary sinus of the heart receives venous blood from which of the following? (D)

a.      The great cardiac vein

b.     The middle cardiac vein

c.      The small cardiac vein

d.     All of the above

 

13.  Individual cardiac muscle fibers are joined to one another by structures called: (B)

a.      tight junctions.

b.     intercalated discs.

c.      chordae tendinae.

d.     T tubules.

 

14.  Within arteries, smooth muscle is found: (B)

a.      mostly within the tunica intima.

b.     mostly within the tunica media.

c.      mostly within the tunica adventitia.

d.     equally distributed between the tunica intima, tunica media, and tunica adventitia.

 

15.  Which of the following types of blood vessels consist only of a single layer of endothelium and an underlying basement membrane? (C)

a.      A muscular artery

b.     An arteriole

c.      A capillary

d.     A venule

 

16.  The predominant (that is the thickest) layer within venules and veins is the: (C)

a.      tunica intima.

b.     tunica media.

c.      tunica adventitia.

d.     none of the above because all three layers are of equal thickness.

 

17.  Which of the following capillary types is the least permeable? (A)

a.      Continuous capillaries

b.     Fenestrated capillaries

c.      Discontinuous capillaries

d.     All of the above are of equal permeability

 

18.  Within the systemic circulation, total cross-sectional area is highest in the: (C)

a.      muscular arteries.

b.     arterioles.

c.      capillaries.

d.     medium-sized veins.

 

19.  During the action potential of a cardiac contractile cell, Na+ permeability is highest during: (A)

a.      phase 1 = rapid depolarization.

b.     phase 2 = plateau.

c.      phase 3 = repolarization.

d.     Na+ permeability is the same throughout the action potential.

 

20.  During the rapid depolarization phase of the action potential of a cardiac contractile cell, membrane potential: (B)

a.      changes from +20mV to –90mV.

b.     changes from –90mV to +20mV.

c.      changes from –90mV to –130mV.

d.     remains unchanged.

 

21.  Which of the following cell types possesses pacemaker potentials? (D)

a.      Conducting cells of the sinoatrial (SA) node

b.     Conducting cells of the atrioventricular (AV) node

c.      Purkinje cells

d.     All of the above

 

22.  Like cardiac contractile cells, the repolarization phase of the action potential in cardiac conducting cells is due to an increase in the permeability of which of the following ions? (B)

a.      Na+

b.     K+

c.      Ca2+

d.     Cl-

 

23.  The portion of the conduction system of the heart that carries the impulse forward from the AV node so that it can pass into the ventricles is called the: (C)

a.      internodal pathway.

b.     annulus fibrosus.

c.      bundle of His.

d.     interventricular sulcus.

 

24.  Which of the following portions of the electrocardiogram (ECG = EKG) represents atrial depolarization? (A)

a.      The P wave

b.     The QRS complex

c.      The T wave

d.     The ST segment

 

25.  Which of the following conditions is consistent with an EKG that lacks P waves? (C)

a.      Sinus tachycardia

b.     Sinus bradycardia

c.      Atrial fibrillation

d.     All of the above

 

26.  In cardiac contractile cells, relaxation of the muscle fiber occurs: (B)

a.      during the plateau phase of the action potential.

b.     when intracellular Ca2+ is reduced through the action of Ca2+ pumps.

c.      when intracellular Ca2+ is increased by opening of Ca2+ channels.

d.     both a and c.

27.  During the cardiac cycle, the second heart sound is attributable to the: (D)

a.      opening of the mitral valve.

b.     closing of the mitral valve.

c.      opening of the aortic semilunar valve.

d.     closing of the aortic semilunar valve.

 

28.  The volume of blood left in the left ventricle following ventricular ejection is called the: (D)

a.      maximum diastolic potential (MDP).

b.     dicrotic notch.

c.      end diastolic volume.

d.     end systolic volume ( = residual volume).

 

29.  Cardiac output is computed from the product of stroke volume and: (D)

a.      end systolic volume ( = residual volume).

b.     end diastolic volume (EDV).

c.      total peripheral resistance (TPR).

d.     heart rate (HR).

 

30.  The amount of blood that leaves the ventricle each beat is called the: (B)

a.      cardiac output.

b.     stroke volume.

c.      heart rate.

d.     end diastolic volume (EDV).

 

31.  Which of the following terms refers to the pressure that must be overcome for the ventricle to eject blood from the heart? (B)

a.      Preload

b.     Afterload

c.      Contractility

d.     End diastolic pressure (EDP)

 

32.  Which of the following conditions will decrease stroke volume? (D)

a.      An increase in venous return due to exercise

b.     An increase in contractility due to sympathetic stimulation

c.      A decrease in heart rate

d.     An increase in mean arterial pressure in the aorta

 

33.  Any agent that is able to increase the contractility of the heart is called a: (A)

a.      positive inotropic agent.

b.     negative inotropic agent.

c.      positive chronotropic agent.

d.     negative chronotropic agent.

 

 

 

34.  Which of the following will result in an increase in heart rate (HR)? (C)

a.      An increase in parasympathetic input to the heart

b.     A decrease in the slope of the pacemaker potential of SA node cells

c.      Cutting all the nerves to the heart

d.     All of the above

 

35.  Which of the following conditions will result in an increase in cardiac output? (D)

a.      An increase in venous return due to an increase in blood volume

b.     A fall in mean arterial pressure within the aorta

c.      An increase in sympathetic stimulation to the heart due to exercise

d.     All of the above

 

36.  Within the systemic circulation, the velocity of blood flow is lowest in the: (C)

a.      aorta ( = an elastic artery).

b.     arterioles.

c.      capillaries.

d.     vena cava ( = large vein).

 

37.  According to Poiseuille’s Law, which of the following would be expected to increase vascular resistance within an arteriole? (B)

a.      Vasodilation of the vessel

b.     Vasoconstriction of the vessel

c.      A decrease in hematocrit so that blood viscosity decreases by 20%

d.     Both a and c

 

38.  Which of the following will result in an increase in pulse pressure? (C)

a.      A decrease in stroke volume

b.     An increase in the peripheral runoff of blood

c.      A decrease in arterial compliance

d.     An increase in arterial compliance

 

39.  When determining blood pressure by sphygmomanometry, the cuff pressure where the first Korotkoff  sound is heard corresponds to the: (A)

a.      systolic pressure.

b.     diastolic pressure.

c.      mean arterial pressure.

d.     central venous pressure.

 

40.  Mean arterial pressure is equal to the product of: (C)

a.      stroke volume multiplied by heart rate.

b.     stroke volume multiplied by total peripheral resistance.

c.      cardiac output multiplied by total peripheral resistance.

d.     pulse pressure multiplied by heart rate.

 

 

 

41.  Which of the following will cause mean arterial pressure to decrease? (C)

a.      An increase in stroke volume

b.     An increase in heart rate

c.      A decrease in total peripheral resistance

d.     All of the above

 

42.  Within typical systemic capillaries, which of the following Starling forces changes the most as blood flows from the arterial end to the venous end of the capillary? (A)

a.      Blood hydrostatic pressure (BHP)

b.     Interstitial fluid hydrostatic pressure (IFHP)

c.      Blood colloid osmotic pressure (BCOP)

d.     Interstitial fluid osmotic pressure (IFOP)

 

43.  Which of the following conditions will favor edema ( = accumulation of interstitial fluid)? (C)

a.      A decrease in blood pressure

b.     An increase in the concentration of plasma proteins

c.      An increase in capillary permeability

d.     All of the above

 

44.  As a result of the myogenic response, a 20% increase in blood pressure to an artery will result in: (D)

a.      a 20% increase in blood flow.

b.     a 20% decrease in blood flow.

c.      vasodilation of the vessel.

d.     an increase in the vascular resistance of the vessel.

 

45.  As a result of metabolic hyperemia, increases in tissue metabolism are associated with: (B)

a.      vasoconstriction.

b.     vasodilation.

c.      decreases in blood flow.

d.     both a and c.

 

46.  Which of the following relay information pertaining to blood PO2, PCO2, and pH to the cardiovascular centers within the brainstem? (C)

a.      Sensory nerves associated with baroreceptors

b.     Sensory nerves associated with stretch receptors

c.      Sensory nerves associated with chemoreceptors

d.     Sensory nerves associated with muscle receptors

 

 

 

 

 

 

47.  As a result of the baroreceptor reflex, an increase in blood pressure results in: (D)

a.      an increase in the sympathetic stimulation to the heart.

b.     a decrease in the frequency of action potentials in sensory nerves associated with baroreceptors.

c.      an increase in heart rate.

d.     an increase in the parasympathetic stimulation to the heart.

 

48.  In response to increased stretch of the atrial wall, atrial cells of the heart release: (D)

a.      anti-diuretic hormone (ADH).

b.     angiotensin II.

c.      aldosterone.

d.     atrial natriuretic peptide (ANP).

 

49.  Which of the following can cause vasoconstriction of blood vessels? (D)

a.      Angiotensin II

b.     ADH

c.      An increase in sympathetic stimulation

d.     All of the above

 

50.  In a patient with hypovolemic shock as a result of hemorrhage, all of the following will increase except: (C)

a.      heart rate.

b.     total peripheral resistance.

c.      ANP.

d.     renin release.