Otalgia considered as an affection of the sensory system of the seventh cranial nerve / by J. Ramsay Hunt.

  • Hunt, James Ramsay, 1872-1937.
Date:
[1907]
Catalogue details

Licence: In copyright

Credit: Otalgia considered as an affection of the sensory system of the seventh cranial nerve / by J. Ramsay Hunt. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    primitive forms of life, is the nerve of the first branchial or ear cleft (the spiracle). From the ear cleft are developed the structures of the middle and external ear. Not only is there this relation to the conducting mechanism of the ear, but both the 7 th and 8th nerves spring from a common ganglionic outgrowth of the neural ridge (the ganglion acustico-facialis). From the ganglion acusticum, which joins the otic vesicle, are developed the ganglia of Corti, Scarpa, and the auditory nerve. The ganglion faciale is represented at a later period of development by the geniculate ganglion, from which is developed the pars intermedia or nerve of Wrisberg; so that in developmental processes there is found a most intimate relationship be- tween the facial nerve and its ganglion, the ganglia of the acoustic nerve, and all those structures which go to form the auditory mechanism. Anatomically, the facial is a mixed nerve, as are the 5 th, 9th, and 10th nerves, having a motor and a sensory root and ganglion. Its ganglion, the geniculate, is situated at the entrance to the aqueduct of Fallopius, in the depths of the internal auditory canal. This structure contains cells of the so-called spinal type, and is the homo- logue of the Gasserian ganglion and the posterior root ganglia of the spinal cord. There passes from it cen- tripetally the nerve of Wrisberg (Fig. 2) on its way to the medulla oblongata, lying between the 7 th and the 8th nerves. This represents the sensory root of the 7th. The distal or peripheral branches of the ganglion are three in number (Fig. 1). 1. The great superficial petrosal nerve; passing to Meckel’s ganglion on the second division of the 5th, giving off in its course a branch which enters into the formation of the tympanic plexus (the great deep petrosal nerve). 2. The small superficial petrosal nerve; which passes to the otic ganglion on the third division of the 5th, like- wise giving off in its course a branch to the tympanic plexus (the small deep petrosal nerve).
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