GENERAL HISTOLOGY

Detailed explanation-1: -The main component is the actin filament, which is formed from the polymerization of globular actin molecules. Each globular actin monomer contains a binding site for the globular myosin head. Along the entire length of the thin filament, actin monomers spiral around a structural protein called nebulin.

Detailed explanation-2: -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.