30 ANATOMY OP THE HEAD AND NECK. 



the brain by a peduncle, which should be noticed. In the 

 foetus the pituitary body is hollow, and communicates with 

 the third ventricle through the infimdibuhim. It was by 

 virtue of this communication that Yesalius believed the 

 fluid of the ventricles was transmitted to the pituitary 

 body, and from it through the sphenoidal sinuses to the 

 nasal fossae, thus causing the disease called pituita, or 

 catarrh ; a theory which charlatans still find for their ad- 

 vantage to maintain. 



The dura mater is supplied by a number of arteries 

 called meningeal. The anterior meningeal, an offset from 

 the ethmoid branch of the internal carotid, is a small 

 artery which enters the skull by a foramen between the 

 ethmoid and frontal bones, and is distributed to the dura 

 mater in that vicinity. The middle meningeal artery is a 

 branch of the internal maxillary ; it enters the skull by the 

 spinous foramen of the sphenoid bone, and passing into a 

 deep groove in the inferior angle of the parietal bone, 

 spreads over the side of the cranial cavity ; the meningea 

 parva, from the same source, enters by the foramen ovale, 

 and is distributed to the middle cranial fossa. The in- 

 ferior meningeal arteries are branches from the ascending 

 pharyngeai and occipital, which enter by the foramen 

 lacerum posterius, and, together with ihe posterior menin- 

 geal, from the vertebral artery, supply the middle and pos- 

 terior cranial fossae. 



The vertebral arteries will be seen entering the foramen 

 magnum, where they pierce the dura mater. The arteries 

 of the two sides converge in front of the medulla oblon- 

 gata, and become united in one trunk, the basilar, which 

 will be described with the base of the brain. The vertebral 

 artery gives off many small branches, and one of some 

 size, the posterior meningeal, to the cerebellar fossa and 

 the falx cerebelli. 



The internal carotid artery perforates the base of the 

 skull, at the apex of the petrous portion of the temporal 

 bone ; given off from the common carotid in the neck, it 

 ascends to the carotid foramen in the temporal bone, and 

 pursuing a tortuous course in an osseous canal through 

 that bone, enters the cranial cavity. The cranial part of 

 the vessel describes an S-like curve at the side of the sella 

 turcica where it lies in the cavernous sinus ; near the ante- 

 rior clinoid process it gives off the ophthalmic artery, and 

 then, turning upward, divides into branches to supply the 



