heart rate is approximately 100 beats/mt.
iv. Sympathetic stimulation of heart increasing rate of transmission in cardiac
conductive tissue is chronotropic effect.

B:-Only i, ii and iii

C:-Only i, iii and iv

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

Question50:-Which of the following statement is/are true about P-glycoprotein in
cerebral capillaries ?

i. A multidrug nonspecific transports in apical membrane of endothelial cells.

ii. It is an ATP dependent efflux pump.

iii. Transports drugs and peptides that cross cerebral capillaries back into blood.
iv. Blocks various anticancer drugs from entering brain and tumor tissues.

A:-Only i, ii and iv

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

Correct Answer:- Option-C

Question51:-Which of the following statement is/are false about Nitric oxide ?

i. Nitric oxide synthase 1 is found in endothelial cells and catalyze the reaction of
synthesis of nitric oxide from Arginine.

ii. Flow induced dilatation in large arteries to tissues is due to local release of nitric
oxide.

iii. Nitric oxide acting via cAMP is important in brain function.

iv. Nitric oxide is inactivated by hemoglobin through dioxygenation.

A:-Only i and iii

B:-Only i and iv

C:-Only ii and iv

D:-Only i and ii

Correct Answer:- Option-A

Question52:-Which of the following statement is/are true about ECG changes due to
variation in ionic composition of blood ?

i. When plasma x* level rises (+ 7.0 meq/I) first change is appearance of tall
peaked 'T' wave

ii. Plasma «+ level + 8.5 meq/I causes prolongation of QRS complex with tall slender
'T' wave.

iii. Decrease in plasma x+ may cause prominent 'u' wave and late 'T' inversion in
precardial leads.

iv. Hypocalcemia causes prolongation of ST segment and QT interval.

A:-Only i, ii and iii
B:-All the above (i, ii, iii, iv)
C:-Only iii and iv