FASCIA. 411 



CHAPTER III. 



OF THE FASCIA AND MUSCLES OF THE UPPER EXTREMITIES. 

 SECT. I. FASCIA. 



THE muscles of each upper extremity are invested by an apo 

 neurotic membrane called the Fascia Brachialis, which extends 

 from the shoulder to the hand. It begins at the base and spine 

 of the scapula, the margin of the acromion process, the acromial 

 extremity of the clavicle, and from the cellular membrane in 

 the arm-pit, and extends itself over all the muscles of the dor- 

 sum of the scapula, and over the deltoid muscle. The tendons 

 of the latissimus dorsi and pectoralis major, each send off from 

 their margins an expansion which is lost in it. Below the spine 

 of the scapula it is strong and well marked, but on the deltoid 

 muscle, as well as on the muscles of the arm, its desmoid cha- 

 racter is by no means so well developed, though it still retains the 

 appearance of a distinct membrane, and can be raised up as such 

 from the muscles. On the fore arm its ligamentous appearance 

 is well preserved, and extends from the elbow to the wrist in- 

 clusively. Its longitudinal fibres there are well secured by 

 transverse ones. 



Above the condyles of the os humeri, the Fascia Brachialis 

 sends down to the bone a strong tendinous partition to each 

 ridge, and which runs the length of the latter from its upper 

 end to the condyle. These processes separate the muscles on 

 the back of the arm from such as are on the front of it, and are 

 sometimes called the Ligamentum inter-musculare internum and 

 externum. They afford origin to many muscular fibres. At the 

 bend of the elbow, the fascia brachialis is joined by a fasciculus 

 of tendinous matter from the ulriar margin of the tendon of the 

 biceps flexor cubiti, and which, in the contraction of the mus- 

 cle, will keep the fascia tense. 



At the lower extremity of the fore arm, the transverse fibres, 

 after diminishing sensibly, become more numerous, and by their 



