[請益] neuromuscular junction

[NCKUM (成功大學醫學研究所)]

The neuromuscular junction is very efficient, very faithful

(an action potential always generates a contraction), and it can fully control the innervated skeletal muscle (one skeletal muscle only

follows the “order” from one motor neuron).  Explain how these

characteristics are achieved.

我找了課本 也沒說為什麼


當訊息在神經細胞從軸突傳達至突觸時 鈣離子的channel會打開始使鈣離子進入突觸

而造成神經傳導物如Acetylcholine釋放至肌肉細胞

肌肉細胞上acetylcholine receptor便會接收兩個acetylcholine而產生一action

potential造成formation

troponin可偵測鈣離子的濃度 troponin會與鈣離子結合 使tropomysin向前推動

myosin binding site便會與myosin head結合 因此myosin與actin便會連結在一起。

當ATP水解時會使myosin形態改變  牽動actin造成肌肉收縮
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◆ From: 115.43.218.92
※ 編輯: NCKUM           來自: 115.43.218.92        (09/21 23:13)
※ NCKUM:轉錄至看板 Medicine                                       09/22 22:11
推 mulkcs:你的問題主要是什麼呢?我感覺是one skeletal muscle follow
推 mulkcs:one motor neuron 這句。
The neuromuscular junction is very efficient (it takes a very
short time to pass the signal from the motor neuron to the muscle), very
faithful (an action potential always generates a contraction), and it can
fully control the innervated skeletal muscle (one skeletal muscle only
follows the “order” from one motor neuron).  Explain how these
characteristics are achieved.

但我不大知道怎解釋
※ 編輯: NCKUM           來自: 115.43.218.92        (09/23 12:55)
※ NCKUM:轉錄至看板 Biology                                        09/23 23:45
推 teamophoenix:我不確定我講得對不對~~不過在muscle上應該不會講
→ teamophoenix:action potential 因為肌肉上不會有threshold，只有
→ teamophoenix:神經上會講action potential，motor neuron可以產生
→ teamophoenix:的電訊號是all or none，所以每個action potential
→ teamophoenix:都是一個相同大小的訊號，而雞肉因為不是all or none
→ teamophoenix:的action potential 且可以隨著motor neuron刺激平率
→ teamophoenix:增加而summation。我只是想跟你講說不會用action
→ teamophoenix:potential 這個詞
→ NCKUM:XD不是我出的題..