Muscle Physiology - Sarcotubular system Flashcards
What is the cell membrane of the muscle fibre called ?
Sarcolemma
What are T-tubules ?
The T-tubules are invaginations of the sarcolemma that form a permeability barrier between the cytosol and the extracellular space.
What is sarcoplasm ?
Sarcoplasm is the cytoplasm of the muscle cells.
What is the sarcoplasmic reticulum ?
The endoplasmic reticulum of the muscle cell is the sarcoplasmic reticulum. This is important for the storage of calcium.
What does the sarcoplasmic reticulum store ?
calcium
What is on either side of a t-tubule ?
On either side of a T-tubule is a sarcoplasmic reticulum.
What is the triad ?
Triad- Two terminal cisternae and one TT.
What is a motor unit of the muscle ?
Motor unit of the muscle – A single motor neuron supplying the muscle.
What is the neuromuscular junction?
Neuromuscular junction – The junction between the nerve and the muscle.
What receptors do T tubules contain ?
- T-Tubules contain Dihydropyridine receptors.
What receptors do the L tubules contain ?
- L tubules have Ryanodine receptors sitting on the sarcoplasmic reticulum.
Explain the function of the sarcotubular system
1- Whenever an action potential reaches the muscle, the action potential activates the dihydropyridine receptor.
2- The dihydropyridine receptor activated the ryanodine receptor.
3- Calcium is then released into the sarcoplasm.
