GENERAL HISTOLOGY

Detailed explanation-1: -Myofibrils are composed of long proteins including actin, myosin, and titin, and other proteins that hold them together. These proteins are organized into thick, thin, and elastic myofilaments, which repeat along the length of the myofibril in sections or units of contraction called sarcomeres.

Detailed explanation-2: -The fundamental repeat unit within muscle that is responsible for contraction is the sarcomere. The sarcomere consists of a bundle of myosin-containing thick filaments flanked and interdigitated with bundles of actin-containing thin filaments (Fig. 1).

Detailed explanation-3: -The myofibrils are bundles of interconnected protein filaments of striated muscles. The filaments (myofilaments) included in the myofibrils are mainly thick filaments (myosin), and thin filaments (actin).