MUSCLES ON THE ANTERIOR PART OF THE FOREARM. 



365 



Use. To bend the hand, and to stretch the membrane that 

 is expanded on the palm. ^ 



N. B. This muscle is sometimes wanting, but the aponeu- 

 rosis palmaris is always to be found. 



2. Pronator Radii Teres, 



Arises, fleshy, from the internal condyle of the os humeri, 

 Fig. 94.* and tendinous from the coronoid process of 

 the ulna. 



Inserted, thin, tendinous, and fleshy, into 

 the middle of the posterior part of the radius. 

 Use. To roll the radius, together with the 

 hand, inwards, 



3. Flexor Carpi Radialis, 

 Arises, tendinous and fleshy, from the 

 internal condyle of the os humeri, and from 

 the anterior part of the upper end of the 

 ulna, where it firmly adheres to the pronator 

 radii teres. 



Inserted, by a flat tendon, into the fore 

 and upper part of the metacarpal bone that 

 sustains the forefinger, after running through 

 a fossa in the os trapezium. 



Use. To bend the hand, and to assist in 

 its pronation. 



4. Flexor Carpi Ulnaris, 

 Arises, tendinous, from the internal con- 

 dyle of the os humeri. It has, likewise, a 

 small fleshy beginning from the outer side 



* Superficial layer of muscles of the fore-arm. 1. The lower part of the 

 biceps, with its tendon. 2. A part of the brachialis anticus, seen beneath the 

 biceps. 3. A part of the triceps. 4. The pronator radii teres. 5. The flexor 

 carpi radialis. 6. The palmaris longus. 7. One of the fasciculi of the flexor 

 sublimis digitorum ; the rest of the muscle is seen beneath the tendons of the 

 palmaris longus and flexor carpi radialis. 8. The flexor carpi ulnaris. 9. The 

 palmar fascia. 10. The palmaris brevis muscle. 11. The abductor pollicis 

 muscle. 12. One portion of the flexor brevis pollicis ; the leading line crosses 

 a part of the abductor pollicis. 13. The supinator longus muscle. 14. The 

 extensor ossis metacarpi, and extensor primi internodii pollicis, curving around 

 the lower border of the fore-arm. 



31* 



