REGION OF THE FACE. 89 



bone, is the fissura Glased, which crosses the glenoid fossa transversely, 

 and divides it into an anterior smooth surface, bounded by the eminentia 

 articularis, for the condyle of the lower jaw, and a posterior rough surface 

 for a part of the parotid gland. Behind the foramen ovale and spinosum, 

 is the irregular fissure between the spinous process of the sphenoid bone 

 and the petrous portion of the temporal, the foramen lacerum anterius basis 

 cranii, which lodges the internal carotid artery and Eustachian tube, and in 

 which the carotid branch of the Vidian nerve joins the carotid plexus. 

 Following the direction of this fissure outwards we see the foramen for the 

 Eustachian tube, and that for the tensor tympani muscle, separated from 

 each other by the processus cochleariformis. Behind the fissure is the 

 pointed process of the petrous bone which gives origin to the levator pa- 

 lati muscle, and, externally to this process, the carotid foramen for the 

 transmission of the internal carotid artery and the ascending branch of the 

 superior cervical ganglion of the sympathetic ; and behind the carotid 

 foramen, the foramen lacerum posterius and jugular fossa. Externally, 

 and somewhat in front of the latter, is the styloid process, and at its base 

 the vaginal process. Behind and at the root of the styloid process is the 

 stylo-mastoid foramen, for the facial nerve and stylo-mastoid artery, and 

 further outwards the mastoid process. Upon the inner side of the root 

 of the mastoid process is the digastric fossa ; and a little farther inwards, 

 the occipital groove. On either side of the foramen magnum, and near 

 its anterior circumference, are the condyles of the occipital bone. In 

 front of each condyle, and piercing its base, is the anterior condyloid fora- 

 men for the hypoglossal nerve, and directly behind the condyle the irre- 

 gular fossa in which the posterior condyloid foramen is situated. Behind 

 the foramen magnum are the two curved lines of the occipital bone, the 

 spine, and the protuberance, with rough surfaces for the attachment of 

 muscles. 



The FACE is somewhat oval in contour, uneven in surface, and exca- 

 vated for the reception of two principal organs of sense, the eye and the 

 nose. It is formed by part of the frontal bone and by the bones of the 

 face. Superiorly it is bounded by the frontal eminences ; beneath these 

 are the superciliary ridges, converging towards the nasal tuberosity; be- 

 neath the superciliary ridg*es are the supra-orbital ridges, terminating ex- 

 ternally in the external border of the orbit, and internally in the internal 

 border, and presenting towards their inner third the supra-orbital notch, 

 for the supra-orbital nerve and artery. Beneath the supra-orbital ridges 

 are the openings of the orbits. Between the orbits is the bridge of the 

 nose, over-arching the anterior nares ; and on each side of this opening 

 the canine fossa of the superior maxillary bone, the infra-orbital foramen, 

 and still farther outwards the prominence of the malar bone ; at the lower 

 margin of the anterior nares is the nasal spine, and beneath this the supe- 

 rior alveolar arch, containing the teeth of the upper jaw. Forming the 

 lower boundary of the face is the lower jaw, containing in its alveolar 

 process the lower teeth, and projecting inferiorly to form the chin; on 

 either side of the chin is the mental foramen. If a perpendicular line be 

 drawn from the inner third of the supra-orbital ridge to the inner third of 

 the body of the lower jaw, it will be found to intersect three openings ;-- 

 the supra-orbital, infra-orbital, and mental, each giving passage to a facial 

 branch of the fifth nerve. 



