Physiology - from Ganong's 23rd ed Chapter 31 - The Heart as a Pump

Question 1

The second heart sound is caused by

A) Closure of the aortic and pulmonary valves

B) Vibrations in the ventricular wall during systole

C) Ventricular filling

D) Closure of the mitral and tricuspid valves

E) Retrograde flow in the vena cava

Answer 1

A

Question 2

The fourth heart sound is caused by

A) Closure of the aortic and pulmonary valves

B) Vibrations in the ventricular wall during systole

C) Ventricular filling

D) Closure of the mitral and tricuspid valves

E) Retrograde flow in the vena cava

Answer 2

C

Question 3

The dicrotic notch on the aortic pressure curve is caused by

A) closure of the mitral valve

B) closure of the tricuspid valve

C) closure of the aortic valve

D) closure of the pulmonary valve

E) rapid filling of the left ventricle

Answer 3

C

Question 4

During exercise, a man consumes 1.8L of oxygen per minute. His arterial O₂ content is 190mL/L, and the O₂ content of his mixed venous blood is 134mL/L. His cardiac output is approximately

A) 3.2 L/min

B) 16 L/min

C) 32 L/min

D) 54 L/min

E) 160mL/min

Answer 4

C

Use this image of Fick’s Principle

Question 5

The work performed by the left ventricle is substantially greater than that performed by the right ventricle, because in the left ventricle

A) the contraction is slower

B) the wall is thicker

C) the stroke volume is greater

D) the preload is greater

E) the afterload is greater

Answer 5

E

Question 6

Starling’s law of the heart

A) does not operate in the failing heart

B) does not operate during exercise

C) explains the increase in heart rate produced by exercise

D) explains the increase in cardiac output that occurs when venous return is increased

E) explains the increase in cardiac output when the sympathetic nerves supplying the heart are stimulated

Answer 6

D