Question

The functional unit of contractive system in striated muscle is______.

• A. Cross bridges
• B. Myofibril
• C. Sarcomere
• D. Z-band

Answer 1

The correct option is C

Sarcomere

Myofibrils are the elongated contractile threads found in striated muscle cells. Myofibrils are composed of long proteins including actin, myosin, and titin, and other proteins that hold them together. These proteins are organized into thick and thin filaments called myofilaments, which repeat along the length of the myofibril in sections called sarcomeres.The sarcomere is the fundamental unit of muscle structure. Its capacity for contraction is the essential trait that makes muscles work. A and I bands are present in each sacromere