CERVICAL VEETEBE^. 11 



The Inmimc are loug and flat. The superior notches are deeper than 

 the inferior. 



The spinous process is short, horizontal, or only slightly depressed, 

 and bifid ; that of the seventh, however, is longer than the others, and 

 terminates in a tubercle, which is readily felt below the skin, hence the 

 name vertehra prominens, applied to this vertebra. 



The lateral parts usually called transverse -processes are short and 

 bifid, presenting thus at their extremities two tubercles, anterior and 

 posterior, which are named respectively by Owen, jjarapopJii/sis and 

 diapophysis. Each process is deeply grooved superiorly for the spinal 

 nerves, and at its base is perforated vertically by a round foramen, through 

 which in the upper six the vertebral artery and vein pass. It is united 

 with the rest of the vertebra by two parts ; by the posterior, at the 

 place of junction of pedicle and lamina, like a dorsal transverse pro- 

 cess ; by the anterior, to the body of the vertebra, in the same line with 

 the heads of the ribs. The transverse process of the seventh vertebra 

 is large but not bifid, and onlj^ slightly grooved. 



The articular processes are large and flat. Their articular surfaces 

 are oblique, the superior, looking backwards, upwards and slightly 

 inwards ; the inferior forwards, downwards and slightly outwards. 



The foramen is triangular and larger than in the dorsal or lumbar 

 vertebrae. 



The first Cervical Vertebra, or Atlas, differs remarkably from the 

 others, by the absence of a body and spinous process, having the form 

 merely of a large ring with articular and transverse processes. 



Pig. 6. — Atlas V'ertkbra, FROM ABOVE.(A.T.) I Fig. 6. 



1, the anterior arcli, ■with a tubercle in 

 front ; 4, the posterior part of tlie ring, with 

 5, an indication of a spinous tubercle ; 4', the 

 anterior part of the ring, containing the odon- 

 toid process, and indicating in front of 4' the 

 smooth surface on which the process moves 

 in rotation ; 6, the transverse process with a 

 slight indication of division into two tubercles ; 

 7, the condylar articular process ; + inside 

 it indicates the rounded tubercle to which the 

 transverse ligament is attached ; «, the foramen 



in the transverse jirocess ; b, the groove on the '^ 



posterior arch for the vertebral artery. 



The interior- of the ring is wider posteriorly than anteriorly. Its 

 posterior part corresponds to the foramina of the other vertebrfs ; its 

 narrower anterior part is occupied by the odontoid process of the axis, 

 and in the recent state is separated from the posterior by the transverse 

 ligament. In front of the ring is the anterior arch, on the anterior 

 aspect of which is a small tubercle, and on the posterior a smooth 

 surface for articulation with the odontoid process. At the sides of the 

 ring are the lateral masses, which are thick and strong, bearing the 

 articular processes superiorly and inferiorly, and extending outwards 

 into the transverse processes. The articular processes differ from those 

 of other vertebrae in being situated in fi'ont of the places of exit of the 

 nerves. The superior are oval, converging in front, with cartilaginous 

 surfaces concave from before backwards, and looking upwards and 

 inwards. At the inner margin of each is a smooth rounded tubercle, 

 to which the transverse ligament is attached. The inferior articular 



