GENERAL HISTOLOGY

Detailed explanation-1: -The bundles of myofilaments are called myofibrils. The structure of the sarcomere is traditionally described with dark and light bands visible under the microscope. This banding pattern in sarcomeres is due mainly to the arrangement of thick and thin myofilaments in each unit.

Detailed explanation-2: -Myofibrils are composed of smaller structures called myofilaments. There are two main types of filaments: thick filaments and thin filaments; each has different compositions and locations. Thick filaments occur only in the A band of a myofibril.

Detailed explanation-3: -A sarcomere is defined as the region of a myofibril contained between two cytoskeletal structures called Z-discs (also called Z-lines or Z-bands), and the striated appearance of skeletal muscle fibers is due to the arrangement of the thick and thin myofilaments within each sarcomere (Figure 10.2. 2).