CardioVascular PhysiologyMCQs

•1) Consider a capillary in which the net driving force for fluid filtration out of the capillary is 0 mm Hg. Capillary oncotic pressure is 26 mm Hg and interstitial fluid oncotic pressure is 4 mm Hg. Which of the following set of capillary hydrostatic pressure and interstitial fluid hydrostatic pressure is consistent with this?

a-15, -6b-4, 26c-32, -10d-29, 7e-20, 2

•2) The smallest diameter of individual blood vessels is in the:a) Arteriesb) Arteriolesc) Capillaries d) Venulese) Veins

•3) Which of the following will cause vasodilation?a) Decreased potassium conductance in vascular smooth muscleb) Angiotensin IIc) Vasopressind) Hyperpolarization of vascular smooth muscle e) Endothelial cell death

•4) During inspiration, which of the following occur?a) decreased transmural pressure of the right atriumb) decreased intra-chamber pressure in the right atrium c) decreased venous returnd) decreased mean volume in the right atriume) relaxation of the diaphragm

•5) Which of the following will tend to decrease stroke volume?a) increased end-diastolic volumeb) increased end-systolic volumec) increased preloadd) increased afterload e) increased cardiac contractility

•6) When a pregnant uterus presses on the abdominal vena cava, which of the following occurs?a) right atrial pressure increases and femoral (leg) venous pressure increases.b) right atrial pressure increases and femoral (leg) venous pressure decreases.c) right atrial pressure decreases and femoral (leg) venous pressure increases. d) right atrial pressure decreases and femoral (leg) venous pressure decreases.e) no changes in either right atrial or femoral venous pressures.

•7) Which event does occur between the second heart sound and the first heart sound?a) pulmonary valve is openb) aortic pressure reaches systolic pressurec) ventricular ejectiond) isovolumetric ventricular contractione) T wave

•Which of the following will increase the firing rate of a pacemaker cell?a) more negative maximum diastolic potential (MDP) b) less negative threshold potentialc) decreased rate of depolarization of Phase 4d) increased circulating catecholamines e) increased vagal efferent tone to the heart

•9) The ion which is most permeable across the resting cardiac myocyte membrane.

a) Sodium b) Potassium c) Calcium d) Chloride e) Protein

•10) The ion carrying the major inward current during the upstroke of the nerve action potential.

a) Sodium b) Potassium c) Calcium d) Chloride e) Protein

•11) During a cardiac catheterization procedure, you sample blood from various sites. At which site is the partial pressure of oxygen the lowest (most deoxygenated)?a) Pulmonary artery b) Pulmonary veinc) Left atriumd) Left ventriclee) Aorta

•12) At which point in the cardiac cycle are the A-V valves open?a) Rapid filling b) Isovolumetric contractionc) Rapid ejectiond) Isovolumetric relaxatione) None of the above

•13) Insufficiency of the aortic valve would cause:a) Decreased pulse pressureb) Increased mean arterial pressurec) Diastolic murmur d) Decreased arterial oxygen saturatione) Increased flow to the peripheral tissues

•14) If end-diastolic volume were held constant and cardiac contractility were increased, the end-systolic volume would:a) Increaseb) Stay the samec) Decrease d) Not enough information to answer this question.

•15) Moderate hemorrhage would tend to cause which of the following (compare to before the hemorrhage)?a) Increased blood volumeb) Increased parasympathetic tonec) Increased sympathetic tone d) Decreased venous constrictione) Decreased heart rate

•16) In a normal fetus, the umbilical-placental blood flows most directly from:a) Ductus venosusb) Foramen ovalec) Ductus arteriosusd) Aorta e) Pulmonary artery

•17) During the first breath of life:a) Pulmonary arterial pressure increasesb) Pulmonary venous pressure decreasesc) Left atrial pressure increases d) Pulmonary vascular resistance increasese) Foramen ovale flow increases

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18) The direct and reflex responses to intravenous injection of arginine vasopressin include which of the following (consider changes relative to before the injection of angiotensin II):a) increased peripheral resistance and increased heart rate.b) increased peripheral resistance and decreased heart rate c) decreased peripheral resistance and increased heart rated) decreased peripheral resistance and decreased heart ratee) no change in peripheral resistance or heart rate

•19) The direct and reflex responses to intravenous injection of sodium nitroprusside (a donor of nitric oxide in smooth muscle) include which of the following (consider changes relative to before the injection of nitroprusside):a) increased peripheral resistance and increased heart rate.b) increased peripheral resistance and decreased heart ratec) decreased peripheral resistance and increased heart rate d) decreased peripheral resistance and decreased heart ratee) no change in peripheral resistance or heart rate

•20) Which of the following will tend to decrease cardiac output?a) positive pressure (end-expiratory) ventilation (PEEP)b) myocardial infarctionc) Valsalva Maneuverd) Aortic valve insufficiencye) all of the above

• 21) All of the following factors normally increase the length of the ventricular cardiac muscle fibers except:A. Increased venous toneB. Increased total blood volumeC. Increased negative intrathoracic pressureD. Lying to standing change in posture

• 22) Why the cardiac muscle cannot be tetanized?

a. the presence of high intercellular Ca ions

b. the presence of high K ions

c. cardiac muscle is absolutely refractory during part of cardiac cycle

d. cardiac muscle is absolutely refractory during most of cardiac cycle

e. all of the above

• 23. Which of the following is NOT an inward current?

A. I NaB. I CaC. I fD. I Na-K (pump)