[麻醉] 哪一個比重容易被麻醉? myelinated or

[pawn1001 ()]

聰明 + 認真 的大家 應該有發現 regional anesthesia

之中 講義有兩個地方互相矛盾

到底是 myelinated 還是 un-myelinated 的 nerves 比較容易被block呢??


經過 跟老師確認以後

老師的回信如下 :

趕時間的同學請直接看紅字部分


Dear Chang,

    The suggested answer for your question as follows:

     Differential Nerve block- may block other nerves -
     ie. motor nerve paralysis


Determined by nerve size and amount of myelination.
‧ Smaller nerves are blocked first (due to space constant, i.e. distance
   these nerves can passively propagate a current is short - thus easy to stop
   propagation)

‧ Myelinated nerves blocked before unmyelinated of the same size







Size is most important



Smallest to Largest Nerves:

- pain fibers
‧      Type C fibers (polymodal nociceptors - respond to chemicals such as
        bradykinin - dull pain) --
        1 um in diameter and unmyelinated (dull pain)--most sensitive
‧      Type A delta (mechanical and thermal nociceptors) --
        2 um and myelinated (sharp pain)--quite sensitive


希望這樣有幫助到大家

謝謝

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→ pawn1001:對了 原文書也是跟老師相同的意思 ^^
推 craigzeck:推 大感謝~
→ s301069:我和你打賭 這一題不會考
推 chick1227:果然size還是最重要啊
推 cafardpurple:Sizemore!!!