ANATOMY

Detailed explanation-1: -Within the sarcomere, myosin slides along actin to contract the muscle fiber in a process that requires ATP. Scientists have also identified many of the molecules involved in regulating muscle contractions and motor behaviors, including calcium, troponin, and tropomyosin.

Detailed explanation-2: -A sarcomere is the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments-actin and myosin-which are the active structures responsible for muscular contraction. The most popular model that describes muscular contraction is called the sliding filament theory.

Detailed explanation-3: -Sarcomerum. Synonyms: Myomere, Myomerum. The sarcomere is the main contractile unit of muscle fiber in the skeletal muscle. Each sarcomere is composed of protein filaments (myofilaments) that include mainly the thick filaments called myosin, and thin filaments called actin.

Detailed explanation-4: -A muscle contraction is described as isometric if the muscle tension changes but the muscle length remains the same. In contrast, a muscle contraction is isotonic if muscle tension remains the same throughout the contraction.