THE UPPER LIMB 4^3 



dissected. The semispinales and longissimus dorsi having been removed, the 

 multifidus spinae is to be studied, and an eflEort made to show its deepest fibres, 

 called the rotatores spinae. The levatores costarum are to be carefully dissected, 

 and the intertransversales and interspinales are to be looked to, chiefly in 

 the cer\'ical and lumbar regions. 



Pectoral Region and Axillary Space. — To remove the skin, the following 

 incisions should be made : a mesial incision along the sternum ; another from 

 the upper end of this along the clavicle to the acromion process, and thence 

 downwards over the front of the shoulder to the inner side of the arm close to 

 the anterior fold of the axilla ; and a third transversely outwards from the 

 lower end of the sternum. In the case of a female subject, a circular incision 

 should be made around the margin of the areola. In removing the skin 

 from over the mammary gland the fibrous processes, known as the Ugamenta 

 suspensoria of Cooper, which pass between the superficial fascia in front 

 of the gland and the skin, are to be noted. The following cutaneous nerves 

 are to be displayed: (i) the suprasternal, supraclavicular, and supra-acromial 

 branches of the cervical plexus, which descend over the clavicle beneath the 

 platysma myoides ; (2) the anterior cutaneous branches of the intercostal 

 nerves, which emerge through the upper six intercostal spaces close to the 

 sternum ; and (3) the anterior offsets of the lateral cutaneous branches of 

 intercostal nerves below the second, which turn round the anterior fold of the 

 axilla. 



If the subject is a female, the mammary gland should now receive careful 

 attention. Its relation to the superficial fascia, which ensheathes it, is to 

 be studied, and also its relation to the deep fascia covering the pectorahs 

 major. The thin skin of the areola is to be carefully raised towards the 

 nipple, and the galactophorous ducts, each presenting a dilatation or ampulla, 

 are to be shown. An endeavour should be made to display the glandular 

 structure and loculi. 



The pectorahs major and anterior portion of the deltoid are to be dissected, 

 and in the groove between the two the cephahc vein and humeral branch of 

 the acromio- thoracic artery are to be shown. Ljing deeply in the upper part 

 of this groove, just below the clavicle, the infraclavicular glands, two or three 

 in number, are to be looked for. The clavicular part of the pectorahs major 

 should now be divided and reflected. In doing so, the cephalic vein, external 

 anterior thoracic nerve, and branches of the acromio- thoracic artery are to 

 be preserved. The region now being dissected (infraclavicular) hes between 

 the clavicle, pectorahs minor, and upper border of the sterno-costal portion 

 of the pectorahs major. The costo-coracoid membrane, which is a part of 

 the clavi-pectoral fascia, is to be shown, and the stout portion of it, called 

 the costo-coracoid hgament, is to be noted. 



Having studied the connections of the costo-coracoid membrane and the 

 various structures piercing it, the membrane, along with the axillary sheath 

 beneath it, is to be carefully removed, and the first part of the axillary artery, 

 with its branches, the axillary vein, and the trunks of the brachial plexus are 

 to be displayed. The internal anterior thoracic nerve will be found coming for- 

 wards between the artery and the vein, and a communication between it and 

 the external anterior thoracic nerve is to be looked for over the artery'. The 

 posterior thoracic nerve, which hes behind the artery, is to be carefully 

 preserved. The removal of the costo-coracoid membrane will also expose the 

 subclavius muscle. Without further disturbing the pectorahs major mean- 

 while, the axillary space is now to be dissected from below. The axillary 

 fascia forming the floor of the space, and its relations to the fascial investments 

 of the pectorahs major and latissimus dorsi and fascia of the arm are to be 

 noted. The fascia will be seen to be drawn up towards the space, this being 

 due to the insertion of the clavi-pectoral fascia into its upper surface. The 

 axillary fascia having been dissected, the adipose tissue in the space is to be 

 removed with the greatest care. The lateral cutaneous branches of the inter- 

 costal nerves (except the first) will be found on the inner wall between the 

 serrations of the serratus magnus. The lateral cutaneous branch of the second 

 intercostal is to be followed as the intercosto-humeral nerve across the space 



