SCAPULAR MUSCLES, &c. BRACHIAL REGION. 1063 



been already laid bare, and to dissect all the cut muscles, so as to bring 

 their attachments completely into view ; he may then remove the redun- 

 dant masses which are no longer required, preserving only such portions of 

 tendons and muscles as may be necessary for subsequent revision of their 

 relations to the joints and their attachments to the bones. He will then 

 clean the deltoid muscle, beginning from behind, so as to save as much as 

 possible the cutaneous branches of the circumflex nerve (pp. 208 anl 

 645). He will dissect the teres major muscle, and the quadrangular and 

 triangular intervals which are separated by the long head of the triceps 

 muscle, and lie between the teres muscle and the scapula ; and he will lay 

 bare, as far as can be done without injury to the muscles, the structures 

 which pass through these intervals, viz., iu the upper or quadrangular one, 

 the circutbflex nerve, with its branch to the teres minor muscle, and the 

 posterior circumflex artery, and in the lower or triangular interval, the 

 dorsal branch of the subscapular artery (p. 380). The deltoid muscle is 

 next to be removed from the whole of its superior attachment, and beneath 

 it will be seen the bursa that lies between the acromion and shoulder- joint 

 (p. 138), and the branches of the circumflex vessels and nerve. The 

 teres minor, iufraspiuatus and supraspinatus muscles are to be dissected 

 and reflected, and the distribution of the suprascapular nerve and artery 

 traced. While this is done, neither the deltoid ligament nor acromion 

 need be divided. The subscapular muscle is likewise to be examined, 

 with the two short subscapular nerves which supply it ; and on reflecting 

 this muscle, the subscapular bursa will be observed communicating with 

 the shoulder-joint. In removing the muscles attached to the scapula, the 

 student should bring into view the anastomoses of the posterior scapular, 

 suprascapular, acromio-thoracic, dorsal branch of the subscapular, and the 

 circumflex arteries. The scapular muscles may then be cut shorb at their 

 attachments to the humerus. 



4. Subcutaneous view of the Arm. In proceeding with the dissection of 

 the arm, if the part be in a condition favourable for the purpose, the 

 dissector may at once display the cutaneous nerves and veins as far as the 

 wrist (p. 647). He will^ in that case, make an incision all the way down 

 to the wrist in front of the limb ; or, should it be deemed advisable not to 

 remove the integument so far, he may terminate his incision half-way down 

 the fore-arm. For the easier preservation of the cutaneous nerves, which 

 lie close to the aponeurosis of the limb, he will remove the subcutaneous 

 fat by reflecting it in the direction from above downwards. The intercosto- 

 humeral nerve is to be traced down to its distribution (p. 657). The 

 nerve of Wrisberg and the internal cutaneous branch of the musculo-spiral 

 nerve will be most easily traced from their deep origins (pp. 646 and 652). 

 The internal cutaneous nerve will be found piercing the aponeurosis on the 

 inside of the arm in two separate places, a few inches above the elbow ; 

 and on the outer side will be found the two external cutaneous branches 

 of the musculo-spiral nerve, appearing in the line of the external inter- 

 muscular septum ; while at the bend of the elbow, towards the outer side, 

 the musculo-cutaneous or external cutaneous nerve will be observed 

 emerging from the deep parts. Near the elbow, on the inner side, there is 

 a small lymphatic gland, and on the subcutaneous part of the olecranon a 

 small synovial bursa. Further down, there may be seen on the inner side 

 a cutaneous branch from the ulnar nerve, below the middle of the fore- 

 arm ; on the outer side the radial nerve becoming superficial two or three 

 inches above the wrist ; and in front the palmar cutaneous branch of the 



