Full 2L QBank
Physiology Nerve Physiology c4672014

Chronaxie minimum in?

A
Mixed nerves
B
Unmyelinated nerve
C
Myelinated nerve
D
Sensory nerves
High-Yield Explanation
ANSWER: (C) Myelinated nerveREF: Pediatric Anesthesia By Bruno Bissonnette page 758Chronaxie (or chronaxy) is the minimum time over which an electric current, double the strength of the rheobase, needs to be applied, in order to stimulate a muscle fiber or nerve cell.Rheobase is the minimal current amplitude of indefinite duration (practically, a few hundred milliseconds) that results in the depolarization threshold of the cell membranes being reached (i.e. an action potential or the contraction of a muscle).In the case of a nerve or single muscle ceil, rheobase is half the current that needs to be applied for the duration of chronaxie to result in an action potential or muscle twitchRemember chronaxie is the measure of excitability of the nerve. Hence chronaxie is inversely proportional to the myelination of the nerves.Order of neurons in order of increasing chronaxie: A alpha > A delta > C

Related Physiology MCQs

Practice 2,00,000+ NEET PG Questions Free

Timed mock tests, mistake queue analytics, audio lectures & zero attempt limits on i❤️Exams.

Start Free Mock Test Now