OF THE HAND. 



319 



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 meta- 

 carpi. 



The Opponens Minimi Digiti (fig. 173), is of a triangular form, and placed im- 

 mediately beneath the preceding muscles. It arises from the unciform process 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 fifth 

 metacarpal 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. 



MIDDLE PALMAR REGION. 



Lumbricales. Interossei Palmares. 



Interossei Dorsales. 



The Lumbricales 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 contiguous sides of the tendons 

 of the ring and little fingers. They pass forwards to the radial side of the corre- 

 sponding fingers, and opposite the metacarpo-phalangeal articulations each tendon 

 terminates in a broad aponeurosis, which 



is inserted into the tendinous expansion Fl * 178 - e Dorsal Interossei of Left Hand ' 

 from the Extensor communis digitorum, 

 which covers the dorsal aspect of each 

 finger. 



The Interossei Muscles are so named 

 from occupying the intervals between the 

 metacarpal bones. They are divided into 

 two sets, a dorsal and palmar ; the former 

 are four in number, one in each meta- 

 carpal space ; the latter, three in number, 

 lie upon the metacarpal bones. 



The Dorsal Interossei are four in 

 number, larger than the palmar, and 

 occupy the intervals between the meta- 

 carpal 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. 



The First Dorsal Interosseous muscle or Abductor indicis is larger than the 

 others, and lies in the interval between the thumb and index-finger. It is flat, 



