Zucker+Practice+Questions+2023.pdf

A 55 year old female visits her physician complaining of persistent fatigue. She is found to have an O2 saturation of 95% and a hemoglobin of 9g/100ml of blood. What can you conclude from these measurements? (two possible true answers). A. Her O2 content is normal B. Her O2 content is low C....

A 55 year old female visits her physician complaining of persistent fatigue. She is found to have an O2 saturation of 95% and a hemoglobin of 9g/100ml of blood. What can you conclude from these measurements? (two possible true answers). A. Her O2 content is normal B. Her O2 content is low C. Her hematocrit is probably normal D. Nasal O2 would be beneficial In a patient in cardiac arrest, cardiac output is zero. What would be the expected pressure in the systemic arteries and veins if allowed to reach a steady state over time? A. The pressure would equilibrate to a level closer to the normal venous pressure, around 7 mm Hg. B. The pressure in the arteries would be greater than in the veins. C. The pressure would equilibrate to a level close to the normal arterial pressure D. The pressure in the arteries and veins would be zero at equilibrium Which of the following would produce the greatest increase in blood flow through an exercising skeletal muscle? A. Double the radius of the venules B. Decrease the length of the capillaries by 50% C. Double the pressure gradient across the vascular bed D. Decrease the blood viscosity by 50% E. Double the radius of the arterioles In an experimental model of an isolated skeletal muscle, the following parameters were measured: blood flow, 20 ml/min; arterial O2 content, 15 ml O2/ml; venous blood O2 content, 10 ml O2/ml. What is the O2 consumption of this skeletal muscle? A. 200 ml/min B. 100 ml/min C. 300 ml/min D. 500 ml/min A patient has a history of 3-4 min of chest pain (angina) occurring spontaneously at rest. Measurements during such an episode show no change in blood pressure or heart rate, but a decrease in the O2 content of coronary sinus blood from 6 vol% to 3 vol%. What explanation below is most likely the cause of the patient's angina? A. coronary vascular resistance fell B. myocardial O2 consumption must have risen C. coronary vascular resistance remained constant D. coronary blood flow decreased E. None of the above Patients in severe heart failure often have swelling in their feet, ankles and legs, particularly on standing. What is the most likely cause of this form of edema in these patients? A. Decreased iip due to loss of plasma proteins B. Increased Pc due to increased venous pressure C. Increased iii due to increased porosity (leakiness) of the capillaries D. Decreased (i.e. more negative) Pi due to increased lymphatic flow What is the major mechanism by which a sudden increase in arterial blood pressure produces a rapid decrease in heart rate? A. Increase in sympathetic efferent activity B. Activation of the carotid body chemoreceptors C. Decrease in baroreceptor activity D. Increase in vagal efferent nerve activity Which of the following most likely happens at the onset of exercise? A. Decreased cerebral blood flow B. Increased sympathetic outflow C. Decreased coronary blood flow D. Decreased mean systemic filling pressure E. Increased parasympathetic impulses to the heart Which of the following best describes the velocity of blood in the vasculature, assuming blood flow is constant? A. It is greater in the capillaries than in the arteries. B. It is greater in the large veins than in the venules. C. It falls to zero in the descending aorta during diastole. D. It is reduced when an artery is partially constricted E. It is measured in ml per second. When a tumor of the adrenal medulla (called a pheochromocytoma) suddenly discharges a large amount of epinephrine into the circulation, the patient's heart rate would initially be expected to do which of the following? A. Increase because the increase in blood pressure stimulates the carotid and aortic baroreceptors. B. Increase because epinephrine has a direct chronotropic effect on the heart. C. Increase because of increased tonic parasympathetic discharge to the heart. D. Increase because the increase in blood pressure stimulates the carotid and aortic baroreceptors. E. Decrease because of increased tonic parasympathetic discharge to the heart. To calculate cardiac output (CO), one must know which of the following? A. Stroke volume and end systolic volume B. Heart rate and stroke volume C. Ejection fraction and A-V O2 difference D. Rate of O2 consumption and heart rate E. Stroke volume and end-systolic pressure The coronary arteries are: A. dilated by adenosine B. constricted by a direct effect of norepinephrine C. constricted by acetylcholine D. constricted by hypoxia In a patient with mitral stenosis (failure of the valve to open completely), cardiac catheterization findings would indicate which of the following? A. Increased pressure in the right ventricle. B. Increased pressure in the left atrium. C. Increased pressure in the left ventricle. D. Increased pressure in the right atrium E. Normal intracardiac pressures. The pressure differential between the heart and the aorta is least in the A. left ventricle during end systole B. left ventricle during end diastole C. right ventricle during systole D. right atrium during systole E. left atrium during systole Which is true about the venous system? A. In the upright position the venous pressure at the ankle is approximately 7 mm Hg B. In the supine position the venous pressure at heart level is approximately 100 mm Hg C. Venous return increases during inspiration. D. The venous system is low capacitance.