MICROANATOMY

Detailed explanation-1: -The myofilaments act together in muscle contraction, and in order of size are a thick one of mostly myosin, a thin one of mostly actin, and a very thin one of mostly titin.

Detailed explanation-2: -myofibril, muscle fiber, filament, fascicle. The smallest unit is the filaments (actin and myosin) that make up sarcomere. Clumps of filaments make up the microfibrils. The microfibrils make up the myofibers or muscle fibers.

Detailed explanation-3: -Myofibrils are composed of smaller structures called myofilaments.

Detailed explanation-4: -2.1. The smallest contractile unit of skeletal muscle is the muscle fiber or myofiber, which is a long cylindrical cell that contains many nuclei, mitochondria, and sarcomeres (Figure 1) [58]. Each muscle fiber is surrounded by a thin layer of connective tissue called the endomysium.

Detailed explanation-5: -Thin myofilaments are 1 m long and 8 nm in diameter, consisting primarily of actin. Actin is a globular protein with a molecular weight of 43 kDa.