322 HEALTH AND DISEASE 



Insertion. — Into the basilar process of the occipital bone and the body 

 of the sphenoid bone. 



Action. — Acting with its fellow on the opposite side, it flexes the head 

 on the neck. 



Rectus Capitis Lateralis. — A small, fleshy muscle placed beneath 

 the atlas. 



Origin. — From the body of the Ijone last named. 



Insertion. — Into the styloid process of the occipital bone. 



Action. — To assist in flexing the head on the neck. 



Scalenus. — This muscle is situated in front of the first rib, and 

 extends upwards as high as the fourth neck bone. It is composed of 

 two unequal parts, the lower of which is the larger. Between them the 

 axillary plexus of nerves passes on its way to the under part of the 

 scapula, to be distributed to the fore extremity, and parts about the chest, 

 breast, and shoulder. The axillary artery, in leaving the chest to be 

 distributed to the fore-limb, winds round the anterior border of the first 

 rib immediately beneath this muscle. 



Origin. — From the transverse processes of the last four cervical 

 vertebrge. 



Insertion. — Into the anterior border and outer surface of the first rib. 



Action. — By drawing the first rib forward, it assists inspiration. AVhen 

 the rib is fixed and the muscle contracts, the neck would be drawn down- 

 ward and to one side. 



LongUS Colli. — The long muscle of the neck occupies the under sur- 

 face of the bodies of all the cervical and the first six dorsal vertebrge. 



Attachment. — To the bodies of the first six dorsal vertebrae. This 

 portion proceeds forward, to be inserted by a strong tendon into the sixth 

 cervical vertebra. That portion situated in front of the neck has its origin 

 in the transverse processes of the last six cervical vertebrge, and in the 

 bodies of the first six. Its terminal tendon gains attachment to the tubercle 

 on the under surface of the atlas. 



Action. — To bend the neck as a whole, or any part of it. 



MUSCLES OF THE BACK AND LOINS 



Trapezius. — Situated beneath the skin on the side of the neck and 

 withers. It is a fiat, triangular muscle, divided by a tendon into two 

 portions, and sometimes described as two muscles — the cervical and dorsal 

 trapezius. 



Origin. — In front from the superior border of the ligamentum nuchge, 

 from which its fibres pass downwards and backwards. Behind from the 



