MUSCLES OF THE FOREARM. 



715 



Pronator radii teres, (Fig. 227-) Dissection. Make an 

 incision through the integuments along the centre of the 

 forearm, from the elbow to the wrist ; FIG. 227. 

 make a second incision transversely about 

 the middle ; turn off the integuments to 

 the fascia, which latter dissect off sepa- 

 rately, and this muscle will be exposed. 



It arises fleshy from the internal con- 

 dyle, and tendinous from the coronoid 

 process of the ulna ; its course is obliquely 

 across the forearm to be inserted mostly 

 tendinous into the middle of the back 

 part of the radius. .Function. To pronate 

 the hand by rolling the radius inward. 



The flexor carpi radialis (Fig. 22*7) 

 arises tendinous from the inner condyle, 

 and fleshy from the upper part of the 

 ulna, the interrhuscular ligaments, and 

 brachial fascia, forming a thick fleshy 

 belly upon the ulnar side of the last mus- 

 cle, and descends obliquely outward be- 

 neath the anterior annular ligament, 

 through a groove in the os-trapezium, to 

 be inserted into the fore part of the base 

 of the metacarpal bone of the index finger. A bursa is 

 seen between the tendon and os-trapezium. Function. To 

 flex the hand on the wrist. 



This muscle is related with the radial artery, which see. 



The palmaris longus (Fig. 227) arises from the inner 

 condyle by a slender tendon, and fleshy from the inter- 

 muscular ligaments. Forming a short belly, it ends in a 

 long slender tendon, which is inserted into the anterior 

 annular ligament and palmar aponeurosis. 



FIG. 227 represents the Superficial Muscles on the front of the Forearm. 

 1 Inferior portion of the Biceps. 2 Brachialis anticus. 3 Triceps. 4 Pro- 

 nator radii teres. 5 Flexor carpi radialis. 6 Palmaris Longus. 7 Flexor 

 sublimis perforatus. 8 Flexor carpi ulnaris. 9 Fascia palmaris. 10 Pal- 

 maris-brevis muscle. 11 Abductor-pollicis manus. 12 Flexor-brevis pollicis 

 raanus. 13 Supinator radii Longus. 14 Extensor-ossis metacarpi pollicis. 



