Triad
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 triad in muscle contraction consists of a T-tubule and two terminal cisternae of the sarcoplasmic reticulum. It plays a critical role in muscle excitation-contraction coupling by allowing the action potential to be rapidly transmitted deep into the muscle fiber and triggering the release of calcium ions from the sarcoplasmic reticulum, which are essential for muscle contraction.
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.
The transverse (T) tubules are structures in a muscle cell's membrane that deliver signals from the cell surface to the sarcomeres, which are the contractile units of the muscle cell. These T-tubules help coordinate muscle contraction by allowing the signal for muscle contraction to penetrate deeply into the cell.
A tube formed by the inward extension of the cell membrane is called a pseudopod. This structure is used by cells for processes such as engulfing particles or migrating.
Triad
Two terminal cisternae and a T-tubule
one transverse tubule and two terminal cisternae
In skeletal muscle, a triad is formed when a T-Tubule is flanked on either side by the calcium containing Terminal Cisternae of the Sarcoplasmic Reticulum, at the level of the Z-line. The intimate association of these three membranous sturctures (Terminal Cisternae---T-Tubule---Terminal Cisternae) for a Triad. This differs from a diad (or Dyad), in cardiac muscle where the T-Tubule is only intimately associated with ONE Terminal Cisternae.
action potential propagating down the T tubule
It is the terminal cisternae
A muscle triad includes one T-tubule and two terminal cisternae of the sarcoplasmic reticulum. This arrangement is responsible for regulating calcium release during muscle contraction in skeletal muscle cells.
I believe the T-Tubule
Terminal cisternae of the sarcoplasmic reticulum release Ca2+ when signaled by an action potential traveling along the T-tubules. This Ca2+ release triggers muscle contraction by binding to troponin and initiating the sliding of actin and myosin filaments.
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 triad in muscle contraction consists of a T-tubule and two terminal cisternae of the sarcoplasmic reticulum. It plays a critical role in muscle excitation-contraction coupling by allowing the action potential to be rapidly transmitted deep into the muscle fiber and triggering the release of calcium ions from the sarcoplasmic reticulum, which are essential for muscle contraction.
Terminal cisterns of the sarcoplasmic reticulum through the Rhynodine receptors release calcium into the skeletal muscle cell when stimulated by an action potential.