MBBS Physiology

Question 1

What is the normal resting membrane potential of a cardiac ventricular myocyte?

Accepted Answer

-90 mV

Answer

-55 mV

Answer

-70 mV

Answer

-110 mV

Question 2

Which of the following shifts the oxygen-hemoglobin dissociation curve to the right?

Accepted Answer

Increased 2,3-DPG

Answer

Decreased temperature

Answer

Decreased PCO2

Answer

Increased pH

Question 3

The Frank-Starling mechanism of the heart states that:

Accepted Answer

Stroke volume increases with increased end-diastolic volume

Answer

Heart rate increases with increased venous return

Answer

Cardiac output is independent of preload

Answer

Contractility decreases with increased stretch

Question 4

Which hormone is responsible for the long-loop negative feedback on the hypothalamo-pituitary axis in thyroid regulation?

Accepted Answer

T3 and T4

Answer

TSH

Answer

TRH

Answer

Calcitonin

Question 5

What is the GFR (glomerular filtration rate) in a healthy adult?

Accepted Answer

125 mL/min

Answer

60 mL/min

Answer

90 mL/min

Answer

180 mL/min

Question 6

During exercise, which of the following best explains the increase in cardiac output?

Accepted Answer

Increased sympathetic activity and venous return

Answer

Increased vagal tone

Answer

Decreased heart rate with increased stroke volume only

Answer

Peripheral vasoconstriction reducing afterload