Question

Give a brief detail of the physiologic steps to muscle contraction. Explain with support of the appropriate chapters in your book.

Answer 1

Muscular contraction is classified into two types based on change in the length of muscle fibers or tension of the muscle:
1. Isotonic contraction
2. Isometric contraction.
1. Isotonic Contraction
Isotonic contraction is the type of muscular contraction in which the tension remains the same and the length of the muscle fiber is altered (iso = same: tonic = tension).
Example: Simple flexion of arm, where shortening of muscle fibers occurs but the tension does not change.
2. Isometric Contraction
Isometric contraction is the type of muscular contraction in which the length of muscle fibers remains the same and the tension is increased.
Example: Pulling any heavy object when muscles become stiff and strained with increased tension but the length does not change.