Page 8, USMLE, Dr. D. Penney



USMLE-Type Examination Questions - Architecture:


219.  A 60-kg patient has a hematocrit of 40% and a plasma volume of 3 L.  What is his total blood volume?
	(A)	4.0 L
	(B)	5.0 L
	(C)	6.0 L
	(D)	7.0 L
	(E)	greater than 7.5 L


236.  Which of the following statements about the systemic circulation is correct?
	(A)	the velocity of blood flow in the large arteries is from 100 to 500 times faster than in the capillaries
	(B)	the blood volume in the arteries is approximately equal to that in the veins
	(C)	the total cross-sectional area of the capillaries is about 10-fold that of the arteries
	(D)	the velocity of blood flow in the veins is greater than in the arteries
	(E)	blood flow is pulsatile in capillaries


243.  Which of the following structures in the resting subject receives the greatest blood flow per gram of tissue (specific blood flow)?
	(A)	brain
	(B)	heart
	(C)	liver
	(D)	gastrocnemius muscle
	(E)	kidney


244.  The following data are collected from a 22-year-old patient:
	Cardiac output						6 L/min
	Total blood volume					5.5 L
	Average velocity of flow in systemic arteries 		20 cm/sec
	Average velocity of flow in systemic capillaries	0.05 cm/sec
What is the total cross-sectional area for the lumina of the patientıs systemic capillaries (cm2)?
	(A)	600
	(B)	1000
	(C)	1300
	(D)	1700
	(E)	2000


263.  During early ventricular systole, coronary blood flow
	(A)	is more markedly reduced at the subepicardial surface than the subendocardial surface
	(B)	is markedly reduced because the cusps of the aortic valve occlude the coronary arteries and therefore protect them from excess pressure
	(C)	in the left coronary artery goes to near zero or below
	(D)	in the right coronary artery goes to near zero or below
	(E)	is well characterized by all of the above statements


264.  Which one of the following is most likely to occur in a healthy subject in response to running?
	(A)	an increased coronary flow due to decreased cardiac adrenergic tone
	(B)	a generalized increase in blood flow (ie, in the kidneys, muscle, stomach, etc.) due to an increased cardiac output
	(C)	a 10-15 fold increase in coronary flow
	(D)	a decreased cardiac parasympathetic tone
	(E)	a decreased velocity of flow in the capillaries of the lungs


272.  The systemic veins differ from the systemic arteries in all of the following ways, EXCEPT that the systemic veins
	(A)	contain a much greater blood volume
	(B)	are much more compliant
	(C)	have a more variable blood volume
	(D)	have thinner walls
	(E)	in the arms and thighs, contain valves


273.  The pulmonary circulation is similar to the systemic circulation in one important respect
	(A)	the volume of blood in veins in both systems is similar
	(B)	the arteries serve as more important blood volume reservoirs in both
	(C)	the arteries in both systems are of about the same length
	(D)	The same volume of blood flows through the pulmonary vessels and systemic vessels per unit of time
	(E)	adrenergic sympathetic neurons are equally important in controlling arteriolar and precapillary resistances


284.  A 30% decrease in the total blood volume does NOT cause a reflex vasoconstriction in this part of the systemic circulation.
	(A)	coronary circulation
	(B)	cutaneous circulation
	(C)	gastrocnemius muscle circulation
	(D)	renal circulation
	(E)	pulmonary circulation


286.  Its veins have the highest concentration of oxygen found in the systemic circulation.
	(A)	cutaneous circulation
	(B)	gastrocnemius muscle circulation
	(C)	renal circulation
	(D)	pulmonary circulation
	(E)	spleen circulation



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