240 MUSCLES OF THE HAND. 



Dissection. Turn aside the ulnar flap of integument in the palm of the 

 hand : in doing this, a subcutaneous muscle, the palmaris brevis will be 

 exposed. After examining this muscle remove it with the deep fascia, in 

 order to bring into view the muscles of the little finger. 



The PALMARIS BREVIS is a thin plane of muscular fibres which arises 

 from the annular ligament and palmar fascia, and passes transversely in- 

 wards, to be inserted into 'the integument on the inner border of the hand. 



Relations. By its superficial surface with the fat and integument of the 

 ball of the little finger. By its deep surface with the internal portion of the 

 palmar fascia, which separates it from the ulnar artery veins, and nerve, 

 and from the muscles of the inner border of the hand. 



The ABDUCTOR MINIMI DIGITI is a small tapering muscle which wises 

 from the pisiform bone, and is inserted into the base of the first phalanx of 

 the little finger. 



Relations. By its superficial surface with the internal portion of the 

 deep fascia and the palmaris brevis : by its deep surface with the flexor 

 ossis metacarpi and metacarpal bone. By its inner border with the flexor 

 brevis minimi digiti. 



The FLEXOR BREVIS MINIMI DIGITI is a small muscle arising from the 

 unciform bone and annular ligament, and inserted into the base of the first 

 phalanx. It is sometimes wanting. 



Relations. By its superficial surface with the internal portion of the 

 palmar fascia, and the palmaris brevis. By its deep surface with the flexor 

 ossis metacarpi, and metacarpal bone. Externally with the abductor 

 minimi digiti, from which it is separated near its origin by the deep palmar 

 branch of the ulnar nerve and communicating artery. Internally with the 

 tendons of the flexor sublimis and profundus. 



The FLEXOR Ossis METACARPI (adductor, opponens) arises from the 

 unciform bone and annular ligament, and is inserted into the whole length 

 of the metacarpal bone of the little finger. 



Relations. By its superficial surface with the flexor brevis and abductor 

 minimi digiti. By its deep surface with the interossei muscles of the last 

 metacarpal space, the metacarpal bone, and the flexor tendons of the little 

 finger. 



Palmar Region. 

 Lumbricales, 

 Interossei palmares, 

 Interossei dorsales. 



The LUMBRICALES, four in number, are accessories to the deep flexor 

 muscle. They arise from the tendons of the deep flexor ; the first and 

 second from the palmar side, the third from the ulnar, and the fourth from 

 the radial side ; and are inserted into the aponeurotic expansion of the 

 extensor tendons on the radial side of the fingers. The third, or that of 

 the tendon of the ring finger, sometimes bifurcates, otherwise it is inserted 

 wholly into the extensor tendon of the middle finger. 



Relations. In the palm of the hand with the flexor tendons ; at their 

 insertion, with the tendons of the interossei and the metacarpo-phalangeal 

 articulations. 



The PALMAR INTEROSSEI, three in number, are placed upon the meta- 

 carpal bones, rather than between them. They arise from the base of the 

 metacarpal bone of one finger, and are inserted into the base of the first 



