^lUSCLES OF THE HAND. 



221 



brevis and the four deeper extensor muscles receive branches from the interosseous 

 nerve. 



MUSCLES OP THE HAND, 



•Besides the tendons of the long muscles and the lumbricales already 

 described, there are placed in the hand one superficial muscle called 

 palmaris brevis, tlie short muscles 

 of the thumb and little finger, and Fig. ISO. 



the interossei muscles. 



Fig. ISO. — Muscles and Tendons op the 

 Palmar Aspect of the Ha:jd. 5 



Portions of the tendons of the superficial 

 flexor have been cut away to show those of 

 the deep flexor and the lumbricales. 1, ten- 

 don of the flexor carpi radiahs, cut short ; 2, 

 tendon of the flexor carpi ulnaris, inserted 

 into the pisiform bone ; 3, anterior annular 

 ligament of the carpus ; 4, ahductor pollicis ; 

 5, opponens pollicis ; 6, 6, flexor brevis ; 7, 

 adductor pollicis ; 8, abductor minimi digiti ; 

 9, flexor brevis minimi digiti ; 10, lum- 

 bricales, passing to their insertion on the 

 radial side of the four fingers. 



The palmaris brevis is a thin flat 

 subcutaneous nuisele, -which arises 

 fi-om the inner margia of the pahnar 

 fascia and annular ligament ; its 

 fibres proceed transversely inwards, 

 and are inserted into the skin along 

 the inner border of the palm. 



liehit'uim. — The palmaris brevis crosses 

 the muscles of the little linger and covers 

 the ulnar artery and nerve. It is subject 

 to considerable variation in its breadth 

 and thickness, consisting sometimes of 

 only a few scattered fibres. 



Fig. 181. — Deep IVlrscLES of the Palm of 

 THE Haxd. i 

 The abductor pollicis and abductor minimi 

 digiti, together with the anterior annular 

 ligament and the long llexor tendons in the 

 palm have been removed ; in the fore-finger 

 the tendons of both the superficial and deep 

 flexors remain ; in the other fingers the ten- 

 dons of the sui^erfioial flexor liave been 

 removed. 1, pronator quadratus muscle ; 

 2, opponens pollicis ; 3, flexor brevis pollicis ; 

 4, adductor pollicis ; 5, opponens minimi 

 digiti; 6, unciform bone ; 7, 8, interosseous 

 muscles. 



JMuscLES OF THE TiiUMB.— The flcshj mass which forms the thenar 

 eminence, or ball of the thumb, consists of four muscles. 



The abductor pollicis muscle (abductor brevis pollicis,— Alb.), super- 

 ficial and flat, arises from the annular ligament and from the ridge of 

 the OS trapezium, and proceeding outwards and forwards, is inserted 



Fig. 181. 



