MANUAL 



OF 



PRACTICAL ANATOMY. 



THE UPPER EXTREMITY. 



n^HE dissector of the upper extremity begins work on the 

 fourth day after the subject has been placed in the dis- 

 secting-room. He will find the body lying upon its back. 

 The thorax is raised to a convenient height by means of blocks, 

 and a long board is placed under the shoulders for the 

 purpose of supporting trie arms when they are abducted from 

 the sides. 



In dissecting the axilla and thorax it will be found advantageous if the 

 dissectors of the arm and of the head and neck arrange to work at different 

 hours. The dissector of the head and neck, at this stage, is engaged on the 

 posterior triangle of the neck, and the dissection of the triangle cannot be 

 well done unless the arm be placed close to the side and the shoulder 

 depressed. For the dissection of the axilla the arm should be stretched 

 out at right angles to the thorax. A compromise between these two posi- 

 tions always results in discomfort to both dissectors. 



The upper extremity consists of the brachium or arm, 

 the antibrachium or forearm, and the manus or hand. 

 Connected with it are the bones of the shoulder girdle by 

 means of which it is articulated with the skeleton of the body 

 or trunk ; it is also connected with the body by means of 

 a number of muscles. The angle which lies between the 

 arm and the upper part of the trunk is the axilla or armpit. 

 It contains a large number of important blood vessels and 

 nerves. All the above-mentioned structures are to be examined 



VOL. i i 



