318 HEAD AND NECK 



but by removing the orbital process of the palate bone, and a 

 portion of the body of the sphenoid, with the bone forceps, the 

 dissector may expose it more or less satisfactorily. In the same 

 restricted space will be found the terminal portion of the internal 

 maxillary artery, from which numerous branches are given off. 



Ganglion Sphenopalatinum. The spheno-palatine gang- 

 lion is a small, triangular flattened body, which is lodged in 

 the pterygo-palatine fossa. It is embedded in fat, and is 

 surrounded by the terminal branches of the internal maxil- 

 lary artery. Two stout spheno - palatine branches descend 

 to it from the maxillary nerve, but only some of their fibres 

 end in the ganglion ; the remainder are continued directly 

 into the nasal and palatine nerves which proceed from the 

 ganglion. The spheno-palatine branches may be regarded 

 as constituting the sensory roots of the ganglion. 



From the spheno-palatine ganglion branches are given off 

 which radiate in four directions viz., medially, to the nose ; 

 downwards, to the palate ; backwards, to establish connections 

 with the facial nerve and carotid plexus, as well as to supply 

 the mucous membrane of the pharynx ; and, forwards, to the 

 orbit. 



Medial branches, . Posterior superior nasal nerves. 



( Anterior palatine. 

 Descending branches, -j Middle palatine. 



{ Posterior palatine. 



( Nerve of pterygoid canal. 

 Posterior branches, . -j Some lateral posterior superior nasal 



{ branches. 

 Anterior branches, . Orbital. 



From the internal maxillary artery twigs are given off 

 which accompany the above-mentioned nerves. 



Posterior Superior Nasal Nerves. There are two groups of 

 the posterior superior nasal nerves, a medial and a lateral. 

 The medial branches pass through the spheno-palatine 

 foramen and across the roof of the nasal cavity to the posterior 

 part of the septum. The largest of them, the naso-palatine 

 nerve, runs downwards and forwards in a groove on the 

 surface of the vomer (p. 307). Some of the branches of the 

 lateral posterior group also pass through the spheno-palatine 

 foramen and are distributed to the superior meatus, to the 

 superior and middle conchae, and to the posterior ethmoidal 

 air cells. Other branches of the lateral group pass backwards, 

 some in the muco-periosteum of the upper and posterior part 



