Volume 2

Quain's elements of anatomy / edited by Edward Albert Schäfer and George Dancer Thane.

Date:
1895-1898
Catalogue details

Licence: Public Domain Mark

Credit: Quain's elements of anatomy / edited by Edward Albert Schäfer and George Dancer Thane. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    Speedily becoming firm and round, the nerve is directed from the interpeduncular space forwards, as well as somewhat outwards, between the posterior cerebral and superior cerebellar arteries to the outer side of the posterior clinoid process, a little- anterior to which it penetrates the layer of dura mater forming the outer boundary of the cavernous sinus. Contained within this membrane, it continues its course- Fig. 148.—Plan op the third nerve,. WITH THE CILIARY GANGLION, ((i. D. T.) The ganglion is seen to be attached by its short root to the nerve of the inferior oblique muscle ; lr, its long^ and SR, its sympathetic root. forwards to the inner end of the sphenoidal fissure, and there divides into two parts,, upper and lower, which enter the orbit between the heads of the external rectus muscle, and are separated from each other by the nasal branch of the ophthalmic nerve. As the third nerve lies in the outer wall of the cavernous sinus, it is con- nected by slender filaments with the cavernous plexus of the sympathetic, and it receives also a small branch from the ophthalmic division of the fifth nerve. The vpjm; the smaller part, is directed inwards over the optic nerve to the- Fig. 149.—View from above op the motor nerves op the eyeball AND ITS MUSCLES (after Hirschfeld and Leveille, altered). (Allen Thomson.) The ophthalmic division of the fifth pair has been cut short ; the attachment of the muscles round the optic nerve has been opened up, and the three upper muscles turned towards the inner side, their anterior parts being removed ; a part of the optic nerve is cut away to show the inferior rectus ; and a part of the sclerotic coat and cornea is dissected off showing the iris, ciliary muscle, and choroid coat, with the ciliary nerves. a, upper part of the internal carotid artery emerging from the cavernous sinus ; h, superior oblique muscle ; h', its anterior part Ijassing through the pulley ; c, levator palpebrse superioris ; d, superior rectus ; e, internal rectus ; /, external rectus ; /', its upper tendon turned down; g, inferior rectus; h, insertion of inferior oblique muscle. II, optic commissure ; II', part of the optic nerve entering the- eyeball; III, common oculomotor ; IV, trochlear nerve ; V, large root of fifth ; V, small or motor root; VI, abducent nerve ; ], upper division of third nerve, giving twigs to the levator palpebrse and superior rectus ; 2, branches of lower division supplying the internal and inferior recti muscles ; 3, the long branch of the same nerve pro- ceeding forwards to the inferior oblique muscle, and close to the number 3, the short root of the ciliary ganglion : this ganglion is also shown, receiving from behind its long root, which has been cut short, and giving forward some of its ciliary nerves, which pierce the sclerotic coat ; 3', marks the termination of some of these nerves in the ciliary muscle and iris after having passed between the sclerotic and choroid coats ; 4, the trochlear nerve entering the upper surface of the superior oblique muscle ; 6, the abducent nerve passing into the external rectus. superior rectus muscle of the eye and the elevator of the eyelid, to both of which muscles it furnishes branches. The lower and larger portion of the nerve divides into three branches ; of these one reaches the inner rectus ; another the lower rectus ; and the third, the longest of the three, runs onwards between the lower and the outer rectus, and terminates below the ball of the eye in the inferior oblique muscle. The last-mentioned branch is connected with the lower part of the ciliary ganglion by a short thick offset {short root of the- ganglion), and gives one or two filaments to the lower rectus muscle. J