AXILLARY SPACE 21 



the lateral thoracic artery, and receives lymph from the lateral 

 wall of the thorax. (3) A posterior or subscapular group 

 which lie along the subscapular artery on the posterior wall of 

 the axilla, and receive lymphatics from the back. (4) The 

 infraclavicular glands, a group of two or three small glands 

 which lie in the deltopectoral triangle and receive lymph 

 from the upper and lateral parts of the arm. In addition a 

 centra] or intermediate and a subclavicular group of glands 

 are described. The central group lies either on the super- 

 ficial aspect of the axillary fascia, in a pocket of its sub- 

 stance, or deep to the axillary fascia embedded in the adipose 

 tissue of the axilla. The subclavicular glands, from six to 

 twelve in number, lie in the apex of the axilla, they receive 

 afferent vessels from all the lower groups, and their 

 efferents unite together to form the subdavian lymphatic 

 trunk. The student should note that although the various 

 subgroups are more or less separate, and are particularly 

 associated with definite regions from which they receive 

 lymph, nevertheless they are linked together by lymphatic 

 vessels ; therefore micro-organisms which have gained entry 

 into the lymph stream and lymph-borne cancer cells can 

 readily pass from one subgroup to another. 



Kami Laterales (O.T. Lateral Cutaneous Branches) of the 

 Anterior Divisions of the Second and Third Thoracic Nerves. 

 As a rule, the first thoracic nerve does not give off a lateral 

 branch. That which springs from the second thoracic nerve 

 is the largest of the series, and differs from the others in not 

 dividing into an anterior and posterior branch. It is termed 

 the intercosto-brachial nerve, on account of its being distributed 

 to the skin on the medial and dorsal aspects of the upper 

 part of the arm. To reach this destination it crosses the 

 axilla and pierces the deep fascia. But before doing so it 

 establishes communications and forms a plexiform arrange- 

 ment in the axilla with the medial brachial cutaneous nerve, 

 and the lateral cutaneous branch of the third thoracic nerve. 

 This plexus may be joined by another twig, which is occa- 

 sionally present, viz. the minute lateral cutaneous branch of 

 the first thoracic nerve. 



The lateral cutaneous branch of the third thoracic nerve 

 divides into an anterior and posterior part, which are dis- 

 tributed in the ordinary way. From the posterior branch 

 twigs are given to the skin of the axilla, and the terminal 



