Question

How heat is generated during muscle contraction?

Answer 1

Daily routine of an average man involves various activities such as walking, running, writing, etc and all these activities are performed in our body with the help of muscles, and for doing this muscle contraction and relaxation is a basic principle.

Complete answer:
Muscle contraction is an increase in the tension or decrease in the length of a muscle. The muscle tension is a force exerted by the muscle on a bone or the other object. It is isometric if muscle tension changes but the muscle length remains the same, and it is isotonic if muscle length changes but muscle tension remains the same. All skeletal muscle contractions take place as a result of conscious effort originating in the brain.

During the mechanism of muscle contraction, the thin filaments slide over the thick filaments. Signal sent by the central nervous system through the motor neuron initiates the muscle contraction. This process is driven by the cross-bridges which extend from the myosin filaments. The energy source for the contraction is ATP (Adenosine triphosphate) which is manufactured in the muscle fibers, these ATP molecules help in the contraction by binding to the myosin head and getting attached to the actin filament. Most of the energy is used to shorten the muscle fibers but some of this energy is lost as heat during the reaction. Skeletal muscles maintain the temperature homeostasis in the body by the generation of heat which is the by-product of the muscle contraction metabolism.

Note: The mechanism of muscle contraction requires energy and produces heat as a by-product which is very noticeable during physical exercises when muscle movement causes body temperature to rise.