sarcoplasmic reticulum
The part of the skeletal muscle cell that releases calcium when stimulated by the tubules is the sarcoplasmic reticulum (SR). Specifically, the terminal cisternae of the SR release calcium ions into the cytoplasm in response to the action potential transmitted along the T-tubules. This release of calcium is essential for muscle contraction, as it triggers the interaction between actin and myosin filaments.
Skeletal muscle twitch is a single, brief contraction and relaxation cycle, whereas a tetanic contraction involves sustained, rapid repeated contractions without relaxation in between. Tetanic contractions occur when the muscle is stimulated at a high frequency, leading to a fused contraction.
Muscle spindles are the fibers in skeletal muscles that are stimulated by the degree of stretch. These specialized sensory organs detect changes in muscle length and contribute to the stretch reflex, helping to maintain posture and control muscle contraction.
Skeletal or voluntary muscle is capable of rapid contraction and is responsible for skeletal movement.
Cardiac muscle. Unlike skeletal and smooth muscle, the contraction of cardiac muscle is involuntary and requires stimulation from the nervous system. This ensures that the contractions of the heart are synchronized and coordinated.
yes skeletal muscle stretch by means of contraction.
The stimulus that travels from the motor neuron to skeletal muscle is an electrical signal called an action potential. This action potential causes the release of neurotransmitters, specifically acetylcholine, which then stimulates 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.
motor unitUnit
The contraction of the I band in skeletal muscle helps to shorten the muscle fibers, allowing for movement and muscle contraction. This contributes to the overall function of skeletal muscle by enabling the muscle to generate force and produce movement.
stimulation of the muscle by a nerve ending.
during skeletal muscle contraction ,I band and H zone shortens. Sarcomeres