Troponin
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.
Terminal cisterns of the sarcoplasmic reticulum through the Rhynodine receptors release calcium into the skeletal muscle cell when stimulated by an action potential.
When a neuron is stimulated enough, it reaches its threshold potential and fires an action potential. This action potential travels down the axon of the neuron, allowing for the communication of signals to other neurons or cells.
calcium increases the action potential transmitted along the scarcolemma
The action potential increases slightly because more neurons are being stimulated.
When a neuron is sufficiently stimulated, it depolarizes, allowing sodium ions to rush into the cell, triggering an action potential. The action potential travels down the length of the neuron, causing the release of neurotransmitters at the synapse and facilitating communication with other neurons.
This is called action potential. Action potential is the change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.
When Ach enters the synaptic cleft (gap) it open chemically gated sodium channels that starts an action potential spreading through the sarcolemma of the myofibril. This action potential spreads down the T-tubules and "shocks" the sarcoplasmic reticulum into releasing calcium ions.
action potential
The fast rising phase of the SA node action potential is due to the opening of voltage-gated calcium channels. This allows an influx of calcium ions into the cell, leading to depolarization and initiation of an action potential.
sodium potassium and calcium
Calcium