Correct Answer:- Option-B

Question53:-Which of the following statement is/are true about low pressure
baroreceptors in atria ?

i. They are bare ends of myelinated nerve fibers.

ii. They are mechanoreceptors that regulate effective circulating volume and
cardiac output.'

iii. Afferent fibers of atrial receptors project to medulla and hypothalamus.

iv. Increased stretch of atrial B-type receptors like high pressure receptors decrease
heart rate.

A:-i, ii and iii only

B:-i, ii and iv only

D:-All the above i, ii, iii and iv
Correct Answer:- Option-A

Question54:-Which of the following statement is/are true about vasovagal syncope
?
i. Massive vasodilation occurs but resulting fall in blood pressure is not corrected by
baroreceptor response.
ii. There will be profound fall in Mean Arterial Blood Pressure.
iii. Loss of consciousness is due to transient fall in perfusion pressure to brain.
iv. The plasma Arginine Vasopression level is found to be decreased in vasovagal
syncope.

A:-Only i, ii and iii

B:-Only i and ii

C:-Only i, iii and iv

D:-All the above i, ii, iii and iv

Correct Answer:- Option-A

Question55:-Which of the following statement is/are true regarding coronary
circulation ?

i. Receives 15% of cardiac output from left heart and mostly returns it to right
heart.

ii. Changes in heart rate will not affect coronary blood flow.

iii. There is nearly linear correspondence between myocardial oxygen consumption
and myocardial blood flow.

iv. Heart relies primarily on metabolic mechanisms to increase caliber of coronary
vessels.

A:-All the above i, ii, iii, iv
B:-Only iii and iv
C:-Only ii and iii
D:-Only i, iii and iv
Correct Answer:- Option-B
Question56:-Which of the following statement is/are true about non respiratory