Why does the human body needs muscles?

Answer 1

For many reasons. To list a few:

-To provide movement. Without muscles, our bones couldn't move.

-To provide shape and protect vital organs. Muscles cover your belly and chest, and provide a cushion to outside forces.

-To provide heat. Movement, whether voluntary or involuntary (shivering) helps create and maintain body heat.

-To help bloodflow. The contraction and relaxation of muscles, especially in the legs, helps move blood through the venous system and back to the heart.

- To help contain and control the size of "pipes" and other hollow spaces, like blood vessels, airways, and the intestines.