In the given section of the human heart which part ensures that atria contact prior to the ventricles?

1. A

2. B

3. C

4. D

The tricuspid and bicuspid Valves are closed because of

1. Atrial systole

2. Attempted backflow of blood into the atria

3. Ventricular relaxation

4. Ventricular filling

Arrange the following events in a proper sequence.

(i) Increased ventricular pressure

(ii) Attempted backflow of blood into the atria

(iii) Ventricular systole

(iv) Closure of AV valves

1. (i) – (ii) – (iii) – (iv)

2. (ii) – (i) – (iii) – (iv)

3. (iii) – (i) – (ii) – (iv)

4. (i) – (iii) – (ii) – (iv)

During a cardiac cycle:
1. About 70 ml of blood is pumped by the two ventricles
2. The left atrium and the left ventricle contract simultaneously
3. More blood is pumped into the systemic than in pulmonary circulation
4. The atria contract prior to the ventricles

When the sinoatrial node generates an action potential which stimulates both the atria to undergo a simultaneous contraction. it is called atrial systole. This causes the flow of blood into the ventricles and  is responsible for__________ filling of ventricles

1. 70 percent

2. 30 percent

3. 50 percent

4.More than 80 percent

Ventricular contraction is in command of :
1.  S.A. Node
2.  A.V. Node
3.  Purkinje fibers
4.  Papillary muscles

The second heart sound during the cardiac cycle is produced by the:

1. Simultaneous opening of the atrioventricular valves

2. Simultaneous closure of the atrioventricular valves

3. Simultaneous opening of the semilunar valves

4. Simultaneous closure of the semilunar valves

Doctors use a stethoscope to hear the sounds produced during each cardiac cycle. The

second sound is heard when

1. AV valves open up

2. Ventricular walls vibrate due to gushing in of blood from atria

3. Semilunar valves close down after the blood flows into vessels from ventricles

4. AV node receives the signal from SA node

The duration of cardiac cycle is–

1. 0.8 second

2. 0.5 second

3. 0.3 second

4. 0.4 second