404 ANATOMY IN A NUTSHELL. 



the other set below it. After being joined by the long ciliary nerves of the nasal 

 branch of the fifth, they pierce the back part of the sclerotic coat of the eye and 

 then pass forward in grooves on the inner surface of the sclerotic coat to supply 

 the ciliary muscle, iris, and cornea. (Plate CCII). 



LESSON CXIII. 



(2) Meckel's ganglion is also called spheno-palatine and is situated in the 

 spheno-maxillary fossa. It is reddish gray in color and somewhat triangular 

 in shape. It has three roots, (a) a sensory root which comes from the su- 

 perior maxillary nerve through the spheno-palatine branches. Most of the 

 fibers of these nerves pass in front of Meckel's ganglion but a few of them enter 

 it. (b) Its motor root comes from the facial nerve through the great super- 

 ficial petrosal, (c) Its sympathetic root comes from the great deep petrosal 

 which is a branch of the carotid plexus. This motor root and this sensory root 

 unite to make the vidian nerve which enters the posterior surface of the gang- 

 lion. The great superficial petrosal nerve comes from the geniculate ganglion 

 of the seventh nerve in the aqueductus Fallopii. After passing through the 

 hiatus Fallopii, it runs forward in a groove on the anterior surface of the petrous 

 portion of the temporal bone under the dura mater and the Gasserian ganglion. 

 In the middle lacerated foramen it unites with the large deep petrosal which 

 comes from the carotid plexus and runs through the carotid canal on the outer 

 side of the internal carotid artery. It then enters the middle lacerated foramen 

 where with the large superficial petrosal it forms the vidian. This ganglion 

 gives off the following branches, (a) ascending which are two or three small 

 branches pass to the orbit through the spheno-maxillary fissure and supply 

 its p< riosteum, (b) the anterior palatine, sometimes called large palatine, passes 

 through the posterior palatine canal and the posterior palatine foramen to the 

 hard palate where it runs forward in a groove nearly to the incisor teeth. It 

 supplies tin- gums, mucous membrane, and glands, and communicates with the 

 naso-palatine nerves. The inferior nasal branches come from the anterior 

 palatine and pass through foramina in the palate bone and supply the middle 

 meatus and the middle and inferior turbinated bones. The anterior 

 palatine also give s off a palatine branch after leaving the canal which supplies 

 tin- .-oil palate (c) the middle or external palatine is not always present, but 

 when it is it passes through an accessory palatine canal to supply the uvula, 

 tonsil, and soft palab , (d) the posterior or small palatine passes through the 

 small posterior palatine canal to supply the Levator palati, Azygos uvulae, soft 

 palat . tonsil, and uvula. These last two branches with branches from the 

 glosso-pharyngeaJ n< rve form a plexus around the tonsil. This plexus is called 

 circulus tonsillaris, (e) The superior nasal which arefour or five branches pass 

 through the sph< no-palatine foramen where they supply the mucous membrane 

 on tin superior turbinated processes and the middle turbinated boms and also 

 the mucous membrane of tin posterior ethmoidal cells. It communicates with 

 the anti rior dental by a branch which passes to the inner surface of the anterior 

 wall of the antrum of Highmor< . (f) The naso-palatine passes forward through 



