Question

Why is the starting length of the sarcomere important with respect to generating a force (i.e., the length-tension relationship.)? Explain in detail

Answer 1

Length Tension Relationship: It is the isometric force exerted by the muscle which is dependent upon its length. It can be active and passive. The normal range is from 2mm to 2.35mm.

Sarcomere is the basic contractile unit of striated muscle and cardiac muscle.

Sarcomere is overly contracted at rest. The degree of overlap is high between the thick and thin filaments. Actin filaments slide over one another due to muscle contraction. Myosins cause further contractions. Tension decreases due to this.

As the resting muscle length increases, there are more cross bridge cycling when muscles are stimulated to contractions. The resulting tension increases.

The overlap of actin and myosin gives rise to length-tension curve. This in turn influence the sarcomere force output.