OF THE HAND. 



397 



the unciform bone, and anterior surface of the annular ligament, and is inserted 

 into the base of the first phalanx of the little finger, with the preceding. It 

 is separated from the Abductor at its origin, by the deep branches of the uluar 

 artery and nerve. This muscle is sometimes wanting; the Abductor is then, 

 usually, of large size. 



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

 fascia, and the Palmar Brevis. By its deep surface, with the Opponens. 



The Opponens Minimi Digiti (Fig. 240) is of a triangular form, and placed 

 immediately beneath the preceding muscles. It arises from the unciform pro- 

 cess of the unciform bone, and contiguous portion of the annular ligament ; its 

 fibres pass downwards and inwards, to be inserted into the whole length of 

 the metacarpal bone of the little finger, along its ulnar margin. 



Relations. By its superficial surface, with the Flexor Brevis, and Abductor 

 Minimi Digiti. By its deep surface, with the interossei muscles in the fourth meta- 

 carpal space, the metacarpal bone, and the flexor tendons of the little finger. 



Nerves. All the muscles of this group are supplied by the ulnar nerve. 



Actions. The actions of the muscles of the little finger are expressed in their 

 names. The Palmaris Brevis corrugates the skin on the inner side of the palm 

 of the hand. 



PALMAR EEGION. 



Lumbricales. Interossei Palmares. 



Interossei Dorsales. 



The Lumbricales (Fig. 244) are four small fleshy fasciculi, accessories to the 

 deep Flexor muscle. They arise by fleshy fibres from the tendons of the deep 

 Flexor ; the first and second, from the radial side and palmar surface of the 

 tendons of the index and middle fingers ; the third, from the contiguous sides 

 of the tendons of the middle and ring fingers ; and the fourth, from the con- 

 tiguous sides of the tendons of the ring and little fingers. They pass forwards 

 to the radial side of the corresponding 

 fingers, and opposite the metacarpo-pha- 

 langeal articulation each tendon terminates 

 in a broad aponeurosis, which is inserted 

 into the tendinous expansion from the Ex- 

 tensor Communis Digitorum, covering the 

 dorsal aspect of each finger. 



The Interossei Muscles are so named from 

 occupying the intervals between the meta- 

 carpal bones. They are divided into two 

 sets, a dorsal and palmar ; the former are 

 four in number, one in each metacarpal 

 space ; the latter, three in number, lie upon 

 the metacarpal bones. 



The Dorsal Interossei are four in num- 

 ber, larger than the palmar, and occupy 

 the intervals between the metacarpal bones. 

 They are bipenniform muscles, arising by 

 two heads from the adjacent sides of the 

 metacarpal bones, but more extensively 

 from that side of the metacarpal bone which 

 corresponds to the side of the finger in 

 which the muscle is inserted. They are 

 inserted into the base of the first phalanges 

 and into the aponeurosis of the common 

 Extensor tendon. Between the double origin of each of these muscles is a 

 narrow triangular interval, through which passes a perforating branch from 

 the deep palmar arch. 



Fig. 245. The Dorsal Interossei of the 

 Left Hand. 



