Gag reflex

The gag reflex is mediated by a reflex arc whose afferent part forms n. IX. and part n. X., centre in the elongated spinal cord and efferent motor fibres n. X.

The reflex is provided by touching a brush or spatula on the back of the pharynx, with the patient phonizing the letter "á" or "é". The physiological response is elevation and constriction of the pharynx and retraction of the tongue. Examination separately on the left and right will make it possible to distinguish between the afferent lesions (bilateral reduction or disappearance of the response when irritating one side) and the efferent part (unilateral reduction or disappearance of the response when irritation of both sides) of the reflex arc.

Reference

 * 1) ↑ Skočit nahoru k: a b AMBLER, Zdeněk a Josef BEDNAŘÍK, et al. Klinická neurologie. 2. vydání. Praha : Triton, 2008-.  ISBN 9788073871574.
 * 2) ↑ Skočit nahoru k: a b ROTH, Jan, Ondřej FIALA a Evžen RŮŽIČKA. Neurologické vyšetření - norma [online]. [cit. 2012-11-22]. < https://el.lf1.cuni.cz/neurologie >.