264 ANATOMY IN A NUTSHELL. 



with the odontoid process is a diarthrosis joint, subclass trochoides. Blood 

 supply, vertebral and ascending pharyngeal arteries. Nerve supply, loop be- 

 tween the first and second cervical nerves. The part between the posterior 

 surface of the odontoid process and the transverse ligament is a syndesmo- 

 odontoid joint. Each of these joints has a synovial membrane. The synovial 

 membrane of the atlanto-odontoid is surrounded by a capsular ligament of the 

 same name and is continued with the occipito-atlantal capsular ligament. It 

 blends with the anterior occipito-atlantal, atlanto-axial, and the central odon- 

 toid ligaments. The synovial sac of the syndesmo-odontoid joint is surrounded 

 by a capsule. This sac often communicates with the occipito-atlantal synovial 

 sac. 



The ligaments attached to the odontoid process are (1) Occipito-axial lig- 

 ament (apparatus ligamentosus colli) which is a continuation of the posterior 

 common Ligament of the vertebral column, some of the fibers continuing to the 

 anterior margin of the foramen magnum to be continued by the dura mater. 

 This cuvcrs the odontoid process and its ligaments. 



(2) Crucial ligament, the same as the transverse ligament. 



(3) Two lateral odontoid or check ligaments passing from the sides of the 

 apex of the odontoid process to the inner surface of the condyles of the occipital 

 bone, their direction being outward, upward, and forward. 



(4) The central odontoid or suspensory ligament is attached to the tip of 

 the odontoid process below, and to the under surface of the anterior margin of 

 the foramen magnum above. It has in front the anterior occipito-atlantal lig- 

 ament ami behind is the upper division of the crucial ligament. 



LESSON LXXIII. 



The axis is the second cervical vertebra. (Plates XCVI-XCVII.) Its 

 peculiarity is that it has an odontoid process which is in reality the body of the 

 atlas. Its spinous process is bifid. It has fourteen pairs of muscles attached. 

 To body Longus colli 1 Ant. vertebral region. 



Inferior oblique 2 Fifth layer of back. 



Rectus capitis posticus major 3 Fifth layer of back. 



Semispinals colli 4 Fifth layer of back. 



To spinous process Spinalis colli 5 Fourth layer of back. 



[nterspinales 6 Fifth layer of back. 



Multifidus spinae 7 Fifth layer of back. 



Supraspinales 8 Fifth layer of back. 



Splenitis colli 9 Third layer of back. 



Anterior intertransversalis 10 Fifth layer of back. 

 To transverse pro- Posterior intertransversalis 11 Fifth layer of back. 

 cess. Levator anguli scapulae 12 Second layer of back. 



Transversalis colli or cervicis 13 Fourth layer of back. 



Scalenus medius 14 Lateral vertebral region. 



The seventh cervical is the last cervical and has characteristics of both cer- 

 vical and dorsal vertebrae. It is called vertebra prominens on account of its 



