MUSCLE PHYSIOLOGY

Detailed explanation-1: -The major protein components of smooth muscle thin filaments are actin, tropomyosin and caldesmon, present in molar ratios of 28:4:1 respectively. Other smooth muscle proteins which may be associated with the thin filaments in the cell are filamin, vinculin, alpha-actinin, myosin light chain kinase and calmodulin.

Detailed explanation-2: -Each thin filament is made up of three proteins: (1) actin, (2) troponin, and (3) tropomyosin. Actin though is the main protein component of the thin filament.

Detailed explanation-3: -Actin filaments are particularly abundant beneath the plasma membrane, where they form a network that provides mechanical support, determines cell shape, and allows movement of the cell surface, thereby enabling cells to migrate, engulf particles, and divide.