Question

Choose the correct option.

(i) Human heart is ectodermal in origin.

(ii) Mitral valve guards the opening between right atrium and left ventricle.

(iii) SAN is located on the left upper corner of right atrium

(iv) Stroke volume $\times$ Heart rate = Cardiac output

• A. (ii) and (iii) are correct
• B. (iv) alone is correct
• C. (i) and (ii) are correct
• D. (ii) and (iv) are correct
• E. (i) alone is correct

Answer 1

The correct option is B (iv) alone is correct

Correct statement

Statement iv: Stroke volume $\times$ Heart rate = Cardiac output

Elaboration: Cardiac output is the amount of blood pumped by the heart in one minute. It is the product of stroke volume and heart rate.

Stroke volume is the volume of blood that is pumped by the left ventricle. The stroke volume is nearly 70 mL/heartbeat.

Heart rate is the number of times the heart beats in one minute. For an adult human, the heartbeat is 72 times per minute.

Hence, Cardiac output = Stroke volume $\times$ Heart rate.

Final answer
(D) (iv) alone is correct