Question

Read the following four statements (1-4)
(1 ) The second heart sound is DUB, which is associated with the closure of bicuspid and tricuspid valves .
(2) The duration between consecutive second and first heart sound is 0.5 second in a cardiac cycle .
(3) The heartbeat of a human increase when the adrenaline hormone in injected into it.
(4) The atrial systole in a cardiac cycle increase the flow of blood into the respective ventricle by about 70% .
How many of the above statements are incorrect ?

Answer 1

Answer:

1) True

2) True

3)True

4)True

Explanation:

1)The closing of different valves in the heart produces different characteristic sound commonly known as the lub-dub sounds.

2)During the ventricular systole, the blood from the ventricles is drained into the aorta and the pulmonary artery. This is followed by the closing of the AV valves which produces the sound 'lubb' and the closure of the semilunar valves produces the sound 'dubb' , it will take approx. time of 0.5sec.

3)Increasing the heart rate, increasing blood pressure, expanding the air passages of the lungs, enlarging the pupil in the eye.