1 86 J'RACTICAL ANATOMY. 



cess of the ulna. Its nerve-supply comes from the musculo-cutaneous. This 

 muscle and the preceding one act synergistically with the biceps as flexors of 

 the forearm ; they are all three antagonized by the triceps. 



The middle one-third of the humerus (Fig. 129) shows the following muscles 

 exerting traction: (i) The brachialis anticus ; (2) the deltoid; (3) the coraco- 

 brachial ; (4) the upper and lower humeral heads of the triceps, on the posterior 

 surface. 



The capsule of the elbow may now be studied. Remove the insertions of 

 the biceps and brachialis anticus, and expose and cut through the anterior liga- 

 ment of the elbow-joint. 



THE ANTERIOR REGION OF THE SHOULDER. 



Dissection of this region must be preceded by a review of its osteology. 

 Remember, the surgical importance of the shoulder-joint is second to none. 



The Scapula. 



Locate, classify, and describe geometrically this bone. 



It is located on the upper, posterior, and outer aspect of the thorax, limited 

 above by the second and below by the seventh rib. It is a flat bone. It has a 

 dorsal, or posterior, and a ventral, or anterior, surface. It has superior, axillary, 

 and vertebral borders ; an anterior, a posterior superior, and a posterior inferior 

 angle. It has a spine, a coracoid, and an acromion process. 



Give the importance of the following parts of tlie scapula in practical anatomv : 



The anterior angle, or head, articulates with the humerus. 



The anatomical neck gives attachment to the capsular ligament. 



The surgical neck is often the seat of fracture. 



The spine divides the dorsum into supra- and infraspinous fossae. 



The posterior inferior angle is crossed by the latissimus dorsi muscle. 



The supraspinous fossa is occupied by the supraspinatus muscle. 



The infraspinous fossa is occupied by the infraspinous muscle. 



The subscapular fossa is occupied by the subscapularis muscle. 



The superior border has the suprascapular foramen and omo-hyoid muscle. 



The suprascapular foramen transmits the suprascapular nerve. 



The coracoid process gives attachment to three muscles and three ligaments. 



The acromion process gives attachment to the trapezius and deltoid. 



The scapular notch transmits the infraspinous vessels and nerve. 



The scapular angle is the deepest part of the subscapular fossa. 



Name (lie muscles and ligaments you arc expected to find attached to tlic cora- 

 coid process of tlie scapula. 



The short head of the biceps, the coraco-brachialis, and the pectoralis minor 

 muscles ; the coraco-acromial, conoid, and trapezoid ligaments. 



The supra- and infraglcnoid tubercles are where situated and hmc occupied .' 



They are immediately above and below the glenoid cavity of the scapular 

 head respectively : the supraglenoid tubercle gives origin to the long head of the 

 biceps ; the infraglenoid to the long head of the triceps muscle. 



What can you say specifically about tlic origins of the three miisc/es from the 

 three scapular fossce ? 



The whole of the fossa in each case does not give origin to the muscle, only 

 the outer two-thirds thereof. Tlie one-third next the shoulder is occupied by 

 fatty connective tissue, vessels, and nerves. 



