306 



MUSCLES AND FASCIJE. 



the region they occupy. One group occupies the inner and anterior aspect of tho 

 forearm, and comprises the Flexor and Pronator muscles. Another group oc- 

 cupies the outer side of the forearm ; and a third, its posterior aspect. The two 

 latter groups include all the Extensor and Supinator muscles. 



ANTEEIOR BEACHIAL EEGION. 



Fig. 172. Front of the Left Fore- 

 arm. Superficial Muscles. 



Superficial Layer. 



Pronator radii teres. 

 Flexor carpi radialis. 

 Palmaris longus. 

 Flexor carpi ulnaris. 

 Flexor sublimis digitorum. 



These muscles take origin from 

 the internal condyle by a common 

 tendon. 



The Pronator Radii Teres arises by 

 two heads. One, the largest and most 

 superficial, arises from the humerus, 

 immediately above the internal condyle, 

 and from the tendon common to the 

 origin of the other muscles; also from 

 the fascia of the forearm, and inter- 

 muscular septum between it and the 

 Flexor carpi radialis. The other head 

 is a thin fasciculus, which arises from 

 the inner side of the coronoid process 

 of the ulna, joining the preceding at an 

 acute angle. Between the two heads 

 passes the median nerve. The muscle 

 passes obliquely across the forearm 

 from the inner to the outer side, and 

 terminates in a flat tendon, which 

 turns over the outer margin of the 

 radius, and is inserted into a rough 

 ridge at the middle of the outer surface 

 of the shaft of that bone. 



Relations. By its anterior surface, 

 with the deep fascia, the Supinator 

 longus, and the radial vessels and 

 nerve. By its posterior surface, with 

 the Brachialis anticus, Flexor sublimis 

 digitorum, the median nerve, and ulnar 

 artery. Its outer border forms the 

 inner boundary of a triangular space, 

 in which are placed the brachial artery, 

 median nerve, and tendon of the 

 Biceps muscle. Its inner border is 

 in contact with the Flexor carpi 

 radialis. 



The Flexor Carpi Radialis lies on the inner side of the preceding muscle. 

 It arises from the internal condyle by the common tendon, from the fascia of the 

 forearm, and from the intermuscular septa between it and the Pronator radii teres, 

 on the inside; the Palmaris longus, externally; and the Flexor sublimis digitorum, 

 beneath. Slender and aponeurotic in structure at its commencement, it increases 



