How are muscle cells depolarized?
The excitation of skeletal muscle by motor neurons causes the opening of voltage-gated sodium channels. The opening of sodium channels causes depolarization of the skeletal muscle. The action potential from the motor neuron also travels through the T-tubules. Thus, contraction of skeletal muscle occurs.
What is muscle depolarization?
Activation of the nAChR leads to an influx of cations (sodium and calcium) that causes depolarization of the muscle cell membrane. This depolarization in turn activates a high density of voltage-gated sodium channels on the muscle membrane, eliciting an action potential.
What does depolarization mean in relation to a muscle cell?
Depolarization is the process or the act by which polarity is eliminated. It may also refer to the result of such action so that the result is an unpolarized condition. Depolarization in a nerve cell occurs when the cell undergoes an electrical change.
Can muscle cells generate action potentials?
Both neurons and skeletal muscle cells are electrically excitable, meaning that they are able to generate action potentials. An action potential is a special type of electrical signal that can travel along a cell membrane as a wave.
Why does a cell depolarize?
Depolarization and hyperpolarization occur when ion channels in the membrane open or close, altering the ability of particular types of ions to enter or exit the cell. The opening of channels that let positive ions flow out of the cell (or negative ions flow in) can cause hyperpolarization.
What happens during depolarization of the heart?
Depolarization of the heart is the orderly passage of electrical current sequentially through the heart muscle, changing it, cell by cell, from the resting polarized state to the depolarized state until the entire heart is depolarized. What is meant by repolarization of the heart muscle?
