DISSECTION OF THE HEAD AND NECK 273 



Cavernous Sinus (Sinus cavernosus). (Vide Fig. 114.) 



Where is it situated! What are its boundaries! What im- 

 portant structures pass through it? Note the following tribu- 

 taries : 



(a) Superior ophthalmic vein ( V. ophthalmica superior) . 



(b) Inferior ophthalmic vein ( V. ophthalmica inferior). 



(c) Sphenoparietal sinus (sinus sphenoparietalis). 



Arteries of the Region. 



(a) Internal carotid artery (A. carotis interna). How does it enter the 



cranial cavity? Study its course. 

 (aa) Ophthalmic artery (A. ophthalmica). (Vide Fig. 117.) 



FIG. 114. 



N. oculomotorius 



,.X. trochlearis 

 Hypophysis-'llllllllJllp^g^; ^ carotis interna 



X. ophthalmicus 



N. abducens 



maxillaris 

 Sinus sphenoidalis-- -* 



Sinus cavernosus 



Histological section passing in a frontal plane through the hypophysis, adult (after Langer). (From 

 Poirier et Charpy, Traite d'Anat. hum., Paris, 1901, 2 ed., t. ii. p. 767, Fig. 497. ) 



(b) Middle meningeal artery (A. meningea media). Through what open- 



ing does it enter the middle cranial fossa ? In what portion 

 of your dissection did you meet with the origin of this 

 artery? Find the following branches: 



(ba) Superficial petrosal ramus (ramus petrosus superficial) . 



(bb) Superior tympanic artery (A. tympanica superior). 



(c) Accessory meningeal ramus (ramus meningeus accessorius) of A. 



meningea media. Look for it entering the skull through the fora- 

 men ovale. 



Nerves of the Region. 



(a) Trigeminal nerve (N. trigeminus) (0. T. N. cerebralis V.). 



Observe the exact position of the larger portion (portio 

 major) (sensory) and of the smaller portion (portio 

 minor) (motor) and their relations to the semilunar gan- 

 glion (ganglion semilunare [Gasseri]) (0. T. Gasserian 

 ganglion), the cells of which give origin to the sensory 

 fibres of the nerve (vide Fig. 115). Read carefully a de- 

 scription of the semilunar ganglion in your systematic toxt- 

 18 



