Question

Explain the working mechanism of the Human Heart.

Answer 1

Working of Heart: 

• The heart functions as a pump & it keeps the blood circulating in the whole body. The rhythmic contraction of the heart is called a heartbeat. 

Each heartbeat has two parts: 

1.Systole 

2. diastole

• During diastole, the heart receives blood from the veins & during systole it pumps the blood into the arteries. 
• The heart contracts were alternate i.e. when the auricular part contracts, the ventricular part relaxes & vice versa. 
• The number of heartbeats in adult man is 72 per minute. 

Mechanism of heartbeats: 

• The heartbeats begin by the self-contraction of the S-A node. Hence, the S-A node is also called a pacemaker. 
• The S. A. node consists of cardiac muscles and nerve cells. Hence, the heartbeat begins by the contraction of the cardiac muscles Therefore, the heart is also called as myogenic.
• Firstly, the S. A. node contracts, as a result of both the auricles contract. Soon the stimulus of contraction gets transmitted to the A. V. node & from the A.V. node to all over the ventricles with the help of bundle of His & Purkinje’s fibres. It results in ventricular contraction.