The skeletal muscle fiber triad relationship refers to the structural arrangement of a T-tubule sandwiched between two terminal cisternae of the sarcoplasmic reticulum. This triad structure plays a crucial role in excitation-contraction coupling, as it allows for the transmission of action potentials deep into the muscle fiber to trigger calcium release from the sarcoplasmic reticulum for muscle contraction.
The structures within the muscle fiber that shorten to cause skeletal muscle contraction are called myofibrils. Myofibrils are composed of repeating units called sarcomeres, which contain thick and thin filaments made of proteins (actin and myosin). When the muscle fiber is stimulated by a nerve impulse, the myosin heads interact with the actin filaments to generate the force required for muscle contraction.
A skeletal muscle cell is also known as a muscle fiber. It is a long, multinucleated cell that contracts to produce movement in the body.
The structure responsible for storing calcium in skeletal muscle fibers at rest is the sarcoplasmic reticulum. This organelle regulates the release of calcium ions during muscle contraction to trigger the muscle fiber to contract.
Having many nuclei in a skeletal muscle fiber allows for efficient repair and regeneration of the muscle tissue. It enables the muscle fiber to synthesize proteins and grow in response to exercise or injury. Additionally, the multiple nuclei provide more genetic material for protein production, enhancing the muscle's ability to adapt and increase in size.
Skeletal muscle cells are multinucleated because they form from the fusion of multiple myoblasts during development. Each nucleus contributes to the overall functioning and maintenance of the muscle cell. This multinucleation allows for efficient protein synthesis and repair in the large, elongated muscle fibers.
Skeletal
Relaxation of a skeletal muscle usually involves the Golgi tendon proprioceptors.
muscle fiber
true
Sarcoplasm
sarcomeres
muscle fiber, myofibril, myofilaments, sarcomere
sarcomere
they are connected with the rope in the body
motor unitUnit
cardiac muscle appears striated like the skeletal muscle due to arrangement of contractile proteins
muscle spindles