CHAPTER VIII 



THE BLOOD AND LYMPH VESSELS 



THE ARTERIES 



Synopsis of Origin, Distribution, and Anastomoses 



The Axillary Artery. — This is the great vessel which supplies the 

 fore limb. It is naturally divided into two portions where it curves 

 round the anterior border of the first rib, the two parts being termed 

 respectively the intra-thoracic and extra-thoracic divisions. We are here 

 concerned only with the latter division. Assuming that it commences 

 at the anterior border of the first rib below the insertion of the scalenus 

 muscle, it from here takes a course downwards and backwards through 

 the axilla, where it will be found to rest in the loop which we have 

 already described as being formed by the union of the anterior and 

 posterior roots of the median nerve. The artery next crosses the tendon 

 of insertion of the subscapularis muscle on the inner aspect of the 

 shoulder joint, and passing from this tendon downwards it crosses the 

 tendon of insertion of the teres major muscle and becomes directly 

 continued as the brachial artery. Accompanying the artery is its 

 satellite vein. In front of it we find at first the anterior root of the 

 median nerve and subsequently the nerve to the biceps muscle. Behind 

 the vessel we have for a short distance the median nerve, but proceeding 

 down the limb we find that the nerve crosses the vessel, and where the 

 latter becomes continued as the brachial the nerve is placed in front. 



