Page 1 of 1: LA sensitivity ?

mig800 · Credits: 4665 My Scrapbook

Which type of fibres are most sensitive to Local Anaesthetic Action?
Type A,B,C,D ?
Some people believe it shud be type C fibres cause it is the thinnest in diameter while others believe it shud b Type B fibres because it is myelinated.
I wud appreciate if sum1 cud clear this doubt !

guest · Credits: 77790 My Scrapbook My Reading List 262569 Books

Action of local anesthetics is dependent upon Na+ channel activity = use-dependent (frequency-dependent) blockade via high affinity binding to inactivated state of channel.

Small, unmyelinated fibers, such the type C fibers that carry nociceptive signals (pain), are more susceptible to local anesthetic block than are larger fibers.

Nerves that are of small diameter and very active (having high frequency impulses), such as pain fibers carrying signals from damaged tissue, will be preferentially blocked.

manpreet108 · Credits: 30662 My Scrapbook

dr ajay yadav who took a lecture--
told --
inspite of larger size of B fibres ,they are blocked earlier then type C fibres --as B are myelinated and C are not.

so i am going to take final ans as
B>c>A
in this order.

suneet · Credits: 6820 My Scrapbook

manpreet ans is type C>B>A
pressure A>B>C
hypoxia B>A>C
reference table 2-3 page61 ofGANONG 21 EDITION

bhavu · Credits: 9481 My Scrapbook

completly agree with suneet

shraddha · Credits: 19580 My Scrapbook

ya

prasadkumaresan · Credits: 2294 My Scrapbook

i think it is C>B>A
PRESSURE A>B>C
HYPOXIA B>A>C reference ACROSS 2nd edition

konveer · Credits: 640 My Scrapbook

yep C fibres are more sensitive to local anaesthetics.

Akil · Credits: 27618 My Scrapbook

lee's synopsis says

"A-gamma" to be most susceptible and "C-fibers" to be most resistant and infact the smallest c fibres are most resistant....

The rule that smaller fibres are more susceptible to nerve block is said to be applicable only to the myelinated fibres...

Regards,
Akil

ladybird · Credits: 1003 My Scrapbook

SO FINALLYYYYYYYYYYYYYY WHATS THE PICK?

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