704 



DISSECTION OF THE NECK. 



Vessels and 

 nerves. 



the muscular fibres. Smaller glands lie beneath the mucou 

 membrane. 



Other small glands are found at the front and sides of the trachea 

 being situate on and in the fibrous tissue connecting the cartilaginou 

 rings. 



The arteries of the trachea are derived from the inferior thyroi< 

 and bronchial. The veins have a corresponding disposition. Nerve 

 are supplied to the tube from the vagus, mainly through the recur 

 rent laryngeal, and from the sympathetic. 



SECTION XVII. 



PREVEKTEBKAL MUSCLES AND VERTEBRAL VESSELS. 



"Muscles in 

 front of 

 spine. 



Dissection. 



!LonguK 'Colli 

 in three 

 parts: 



vertical, 



and inferior 

 oblique; 



parts in 

 contact 

 with it ; 



Directions. On the piece of the spinal column which was laic 

 .aside after the separation of the pharynx the student is to learn the 

 deep muscles on the front of the vertebrae. 



Dissection. The pre vertebral muscles will be prepared by re 

 moving the fascia and areolar tissue. They are three in number 01 

 each side (fig. 250), and are easily distinguished. Nearest the middle 

 line, and the longest, is the longus colli (A) ; the muscle external to 

 it, which reaches to the head, is the rectus capitis anticus major (B) 

 and the small muscle close to the skull, which is external to the las 

 and partly concealed by it, is the rectus capitis antic as minor (G). The 

 smaller rectus muscle is often injured in cutting through the basilai 

 process of the occipital bone in separation of the pharynx. 



The LONGUS COLLI MUSCLE (A) is situate on the bodies of the 

 cervical and upper dorsal vertebrse, and is pointed above and 

 ibelow. It consists of three parts, one internal or vertical and two 

 external or oblique, which differ in the direction of their fibres, but 

 are closely] united together. The vertical part arises by fleshy and 

 tendinous processes from the bodies of the upper two dorsal and 

 lower two cervical vertebrae, and from the front of the transverse 

 processes of the lower three cervical vertebrae. It is inserted by 

 similar slips into the bodies of the second, third, and fourth cervical 

 vertebrae. The upper oblique part is inclined inwards. It arises from 

 the anterior tubercles of the transverse processes of the third, fourth, 

 and fifth cervical vertebrae, and is inserted into the side of the tubercle 

 on the anterior arch of the atlas. It is generally joined by a slip 

 from the upper end of the vertical part of the muscle. The lower 

 oblique part, passing in the opposite direction to the last, arises in 

 common with the vertical part from the upper dorsal vertebrae, and is 

 inserted into the transverse processes of the fifth and sixth cervical 

 vertebrse. 



In contact with the anterior surface of the longus colli are the 

 pharynx and the oesophagus. The inner border is at some distance 

 from the muscle of the opposite side below, but above only the 



