SHOULDER, AR.\f, FOREARM, AND HAND. 



183 



forget its aponeurotic origin. The muscle originates (i) from the anterior sur- 

 face, upper two-thirds of the ulna ; (2) from the upper three-fourths of the 

 posterior border of the ulna, with the flexor carpi ulnaris and extensor carpi 

 ulnaris muscles. This latter is called the aponeurotic origin. Trace nerves to 

 this muscle from the median and ulnar. 



FIG. 128. DEEP MUSCLES OF PALMAR ASPECT OF FOREARM. 



Lower portion of triceps. 2, 2. Attachments of pronator radii teres. 3. Attachment of flexor carpi 

 radialis, palmaris longus, and flexor sublimis digitorum. 3' '. Tendon of biceps. 3" '. Tendon of 

 brachialis anticus. 4, 4. Flexor carpi ulnaris. 5. Supinator longus. 6. Its distal attachment. 7. 

 Supinator brevis. 7'. Extensor carpi radialis longior. 8, 8. Extensor ossis metacarpi pollicis. 9. 

 Flexor profundus digitorum. 10. Its four tendons. II. Tendon for index finger. 12, 12. Tendon 

 for middle finger. 13. Tendon of flexor sublimis. 14. Tendon of flexor profundus for little finger. 

 15, 15. Lumbricales. 16, 16. Attachments of abductor brevis. 17. Opponens pollicis. 18. Flexor 

 brevis pollicis. 19. Adductor pollicis. 20. Flexor longus pollicis. 21. Its tendon. 22, 22. 

 Attachments of flexor brevis and adductor minimi digiti. 23. Opponens minimi digiti. 



Detach the extreme upper origin of this muscle and study (i) the insertion 

 of the brachialis anticus ; (2) the lesser or coronoid head of the pronator radii 

 teres ; (3) the accessory head of the flexor longus pollicis ; (4) the coronoid origin 

 of the flexor sublimis digitorum. 



