Heart Beat

Q.

What prevents the backflow of blood inside the heart during contraction?

1. Valves in the heart

2. Thick muscular walls of ventricles

3. Thin walls of atria

4. All of the above

Q.

The human heartbeat is about 70 times per minute. The approximate rate of heartbeat in an elephant & a mouse is respectively;

1. 500 & 35 /min

2. 35 & 500 /min

3. 100 & 60 /min

4. 60 & 100 /min

Q.

What is the relationship between rate of heart beats and the rate of pulses?

Q. During the systole phase of cardiac cycle, blood

1. leaves the heart
2. rests in the heart
3. returns to the heart
4. enters the heart

Q. Assertion (A): The force that blood exerts against the wall of a vessel is called blood pressure.
Reason (R): Blood pressure is measured with an instrument called sphygmomanometer.

Q. In which stage of cardiac cycle does the first sharp sound of the heart can be heard?

1. Contraction of atria
2. Relaxation of atria
3. Contraction of ventricles
4. Relaxation of ventricles

Q. Write differences between Systole – Diastole.

Q. Atrio ventricular orifice is guarded by the mitral valve.

1. False
2. True

Q. Atria and ventricle can contract at the same time.

1. False
2. True

Q. Normal blood pressure of an adult human is ______.

1. 100/80 mm Hg

2. 120/80 mm Hg

3. 100/120 mm Hg

4. 80/120 mm Hg

Q. 'P' in the heart have thicker muscular walls than 'Q' do. Also, 'R' ensure that blood does not flow backwards when the 'P' or 'Q' contract. Identify 'P', 'Q' and 'R'.

1. P: Ventricles, Q: Atria, R: Valves
2. P: Atria, Q: Ventricles, R: Valves
3. P: Ventricles, Q: Blood vessels, R: Atria
4. P: Blood Vessels, Q: Atria, R: Valves

Q. Systole is the rhythmic contraction of the heart.

1. False
2. True

Q. Pacemaker is a device placed in the chest to _____________.

1. keep track of heartbeat
2. listen the internal sound of heart
3. prompt heart to beat at normal rate
4. pump blood out of body

Q. Heart receives oxygenated blood from the lungs through pulmonary veins.

1. False
2. True