events at the neuromuscular junction
Süžeeskeem Tekst
- I wonder what it is that causes me to be able to move? If it's not magic or a miracle, what could it be?
- I can help with that! What you're talking about is ca;;ed the neuromuscular junction. It helps our bodies move around.
- I don't believe you know what you're talking about, but i'll listen.
- Alright. There are a variety of steps in the neuromuscular junction. In the first step, nerve impulses arrive at the axon terminals of a motor neuron and trigger the release of acetylcholine
- After that, ACh diffuses and binds to its receptors. This triggers muscle action potential.
- This is madness...
- The action potential travels down the t tubule and opens calcium ion channels in the sarcoplasmic reticulum, and the calcium enters the sarcoplasm.
- Acetylcholinesterase destroys ACh, which prevents more action potential from arising.
- The calcium ion binds to troponin, which causes muscle contraction.
- Oh ok......
- Ca2+ channels will close, and calcium transport pumps will use ATP to restore the low levels of calcium in the sarcoplasm.
- Troponin will return to its original position to block myosin binding sites on actin, which will result in muscles relaxing. Both relaxation and contraction are important for movement.
- WITCH!
- Not really!!
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