
The impulse of heartbeat originates from:
AV node
SA node
Vagus nerve
Cardiac nerve

Important Questions on Body Fluids and Circulation
Match the following related to the cardiac cycle.
Column I | Column II | ||
Cardiac Cycle | |||
Atrial Systole | |||
Ventricular Systole | |||
Cardiac Diastole | |||


Reason (R): In the heart of the human embryo, oxygenated and deoxygenated blood is completely separated.

Give the location of the following valve within the human heart.
Tricuspid valve


Give the location of the following valve within the human heart.
Eustachian valve.



Select the best option from the following statements:
(i) Frog is a poikilothermic
(ii) Frog does not have any coronary circulation
(iii) Heart is "myogenic" in nature
(iv) Heart is autoexcitable

Assertion : Dub' is one of the sounds of the heart caused during a cardiac cycle.
Reason : The sound is due to closure of semilunar valves present at the bases of aortic arches.

Give the location of the following valve within the human heart.
Bicuspid valve

Column A | Column B |
P. Neurogenic heart. | i. Human |
Q. Bronchial heart. | ii. King crab |
R. Pulmonary heart. | iii. Shark |


Give the location of the following valve within the human heart.
Thebesian valve




Statement (S): The sinoatrial node is called 'Pace-maker'.
Reason (R): The sinoatrial node contains specialised cardiomyocytes and generates action potentials without any external stimuli.
The correct answer is



