Question

Put the following in the correct order for the heartbeat?

1. Sinoatrial node
2. Network of fibers in the atria
3. Atrioventricular node
4. Network of fibers in ventricle
5. Atria contracts
6. Ventricle contracts

Answer 1

1,5,2,3,4,6

Explanation:

The sino atrial node generates an action potential which causes the atria to contract thus filling the ventricles. This contraction of atria increases the blood flow to the ventricles by 30%.

This action potential travels via the network of fibres in atria to reach the atrioventricular node. From here the potential spreads along The walls of the ventricles through ventricular fibre bundles (Bundle of His) and causes the ventricles to contract, thus causing the blood to enter the big arteries; aorta and pulmonary artery.