MUSCLES OF THE HAND. 



239 



The FLEXOR Ossis METACARPI (oppo- Fig. 126. 



nens pollicis) arises from the trapezium 

 and annular ligament, and is inserted 

 into the whole length of the metacarpal 

 bone. 



Relations. By its superficial surface, 

 with the abductor pollicis. By its deep 

 surface, with the trapezio-metacarpal ar- 

 ticulation, and with the metacarpal bone. 

 Internally, with the flexor brevis pollicis. 



The flexor ossis metacarpi may now 

 be divided from its origin and turned 

 aside, in order to show the next muscle. 



The FLEXOR BREVIS POLLICIS consists 

 of two portions, between which lies the 

 tendon of the flexor longus pollicis. The 

 external portion arises from the trapezium 

 and annular ligament ; the internal por- 

 tion, from the trapezoides and os mag- 

 num. They are both inserted into the 

 base of the first phalanx of the thumb, having a sesamoid bone in each of 

 their tendons, to protect the joint. 



Relations. By its superficial surface, with the external portion of the 

 palmar fascia. By its' deep surface, with the adductor pollicis, tendon of 

 the flexor carpi radialis, and trapezio-metacarpal articulation. By its ex- 

 ternal surface, with the flexor ossis metacarpi and metacarpal bone. By 

 its inner surface, with the tendons of the long flexor muscles and first 

 lumbricalis. 



The ADDUCTOR POLLICIS is a triangular muscle ; it arises from the whole 

 length of the^metacarpal bone of the middle finger ; and the fibres converge 

 to its insertion into the base of the first phalanx. 



Relations. By its anterior surface with the flexor brevis pollicis, ten- 

 dons of the deep flexor of the fingers, lumbricales, and deep palmar arch. 

 By its posterior surface with the metacarpal bones of the index and middle 

 fingers, the interossei of the second interosseous space, and the abductor 

 indicis. Its inferior border is subcutaneous. 



Ulnar, or Hypothenar Region. 

 Palmaris brevis, 

 Abductor minimi digiti, 

 Flexor brevis minimi digiti, 

 Flexor ossis metacarpi (adductor). 



* The muscles of the hand. 1. The annular ligament. 2, 2. The origin and insertion 

 of the abductor pollicis muscle; the middle portion has been removed. 3. The flexoi 

 ossis metacarpi, or opponens pollicis. 4. One portion of the flexor brevis pollicis. 5 

 The deep portion of the flexor brevis pollicis. 6. The adductor pollicis. 7, 7. Tne 

 lumbricales muscles, arising from the deep flexor tendons, upon which the numbers are 

 placed. The tendons of the flexor sublimis have been removed from the palm of trie. 

 hand. 8. One of the tendons of the deep flexor, passing between the two terminal slips 

 of the tendon of the flexor sublimis, to reach the last phalanx. 9. The tendon of the 

 flexor longus pollicis, passing between the two portions of the flexor brevis to the last 

 phalanx. 10. The abductor minimi digiti. 11. The flexor brevis minimi digiti. The 

 edge of the flexor ossis metacarpi, or adductor minimi digiti, is seen projecting beyond 

 the inner border of the flexor brevis. 12. The prominence of the pisiform bone. 13 

 The first dorsal interosseous muscle. 



