The International Cyclopaedia; A Compendium of Human Knowledge, Revised with Large Additions Volume 10 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 edition. Excerpt: ...1664), whose system is still generally adopted, in nine pairs, which, taken from before backwards in the order in which they are transmitted through the foramina at the base of the skull, stand as follows: 1st, olfactory; 2d, optic; 3d, motores oculorum; 4th, pathetic; 5th, trifacial; 6th, abducentes; 7th, portio dura or facial, portio mollis or auditory; 8th, glossopharyngeal, par vagum or pneumogastric, spinal accessory; 9th, hypoglossal. They may be subdivided into three groups, according to their functions--viz. nerve of special seme--the olfactory (see Nose), optic (see Eye), and auditory (q.v.); nerve of motion, or efferent nerve--the motores oculorum, pathetic, abducentes, facial, and hypoglossal; and compound nerves--the trifacial, glossopharyngeal, pneumogastric, und spinal accessory. The reason why no nerve of taste is included in the above arrangement amongst the nerves of special sense will be subsequently seen; and we proceed briefly to notice the functions of the motor cranial nerves. The 3d, 4th, and 6th pairs--the motores oculorum, pathetic, and abducentes--together make up the apparatus by which the muscles of the orbit (the four recti, the superioi and inferior oblique, and the levator palpebrte) are called into motion, and are sufticientlj noticed in the article Eye. The facial nerve, or the portio dura of the 7th pair, is divisible into three stages. The first stage is the intercranial, from its origin to its exit from the cranial cavity, in association with the portio mollis or auditory nerve (q.v.), at the internal auditory meatus. The second stage is contained in the aqueduct of FaUopiut, a bony canal lying in the petrous portion of the temporal bone. In this stage it anastomizes with other nerves, and thub sensory...