What is heart? Describe the function of heart .

Explanation

### Step-by-Step Text Solution:

1. **Definition of the Heart**:
The heart is a fist-sized organ located in the chest cavity. It is a vital organ of the circulatory system, which is responsible for the circulation of blood throughout the body.

2. **Role in the Circulatory System**:
The heart is often referred to as the primary organ of the circulatory system. It functions as a pump that moves blood to various parts of the body.

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