MICROANATOMY

Detailed explanation-1: -Concentric contraction refers to when the force of contraction exceeds the force of resistance, which results in muscle shortening and approximation of muscle origin and insertion. Eccentric contraction occurs when the force of contraction is less than the force of resistance.

Detailed explanation-2: -Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as when holding something heavy in the same position.