LATERAL PART OF MIDDLE CRANIAL FOSSA 235 



Sinus Cavernosus. The cavernous sinus has been opened 

 by the above dissection. It is a short, wide venous channel, 

 which extends, along the side of the body of the sphenoid bone, 

 from the lower and medial end of the superior orbital fissure 

 (O.T. sphenoidal fissure) to the apex of the petrous portion 

 of the temporal bone. Anteriorly, blood is conducted into it 

 by the ophthalmic veins and the spheno-parietal sinus ; whilst 

 posteriorly, the blood" is drained away by the superior and 

 inferior petrosal sinuses. But it has still other connections. 

 Thus, it receives blood from the lower part of the lateral 

 surface of the brain by the superficial middle cerebral vein 

 and some small inferior cerebral veins. It is united with 

 the corresponding sinus of the opposite side by means of the 



1N T. CAROTID I NFUNDlBULUiv, 



OCULOMOTOR 



TROC HLEAR N 



FIG. 85. Section through the Cavernous Sinus. 

 (After Merkel, somewhat modified. ) 



anterior and posterior intercavernous sinuses (p. 107). Lastly, 

 one or more emissary veins leave its lower aspect ; one passes 

 out of the cranium by the foramen ovale, or it may be 

 through the foramen Vesalii, and ends in the pterygoid venous 

 plexus ; and others accompany the internal carotid artery, 

 through the foramen lacerum and the carotid canal, and end 

 in the pharyngeal plexus. 



The cavernous sinus is formed in the same manner as 

 the other venous sinuses. The two layers of the dura mater 

 are separated from each other, and the interval is lined with 

 a delicate membrane. An intricate network of interlacing 

 trabeculae occupies the lumen of the channel, and it is on 

 that account that the term " cavernous " is applied to the 

 sinus. The cavernous sinus has a special importance on 

 account of its being traversed by the internal carotid artery ; 



