The neuromuscular junction is similar to synapses in the central nervous system in that: (SELECT ALL THAT APPLY) a.) A wave of depolarization in the presynaptic terminal opens voltage gated Ca++ channels b.) Calcium entry through voltage-gated channels in the presynaptic terminal is necessary for the release of neurotransmitter c.) The neurotransmitter released from the pre-synaptic terminal binds to specific receptors on the post-synaptic side d.) The release at the neuromuscular junction of acetylcholine results in just a fraction of a mV depolarization on the post-synaptic membrane which is similar to what is seen at synapses in the central nervous system.
The neuromuscular junction is similar to synapses in the central nervous system in that: (SELECT ALL THAT APPLY)
The neuromuscular junction is a specialized synapse that connects a motor neuron to a muscle fiber. It is responsible for the transmission of nerve impulses from the motor neuron to the muscle fiber, leading to muscle contraction.
When an action potential reaches the presynaptic terminal of the motor neuron, it triggers the opening of voltage-gated calcium channels, allowing calcium ions to enter the presynaptic terminal. The increase in calcium concentration triggers the release of the neurotransmitter acetylcholine (ACh) from the presynaptic terminal into the synaptic cleft.
ACh then binds to nicotinic ACh receptors on the postsynaptic membrane of the muscle fiber, causing the opening of ion channels that allow an influx of sodium ions and an efflux of potassium ions. This results in a depolarization of the postsynaptic membrane, which can trigger an action potential in the muscle fiber and ultimately lead to muscle contraction.
The neuromuscular junction is unique in that it always produces a strong, all-or-nothing response in the muscle fiber, which is necessary for proper muscle function. Dysfunction at the neuromuscular junction can lead to muscle weakness, paralysis, and other neuromuscular disorders.
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