MUSCLES OF THE THOR/tCIC LIMBS. 



183 



Its very thick tendon forms the middle and deep part of the 

 common tendon. 



The common tendon (Fig. 88, c') 

 covers the carpus and metacarpus ven- 

 trally. It divides into five tendons (c) 

 which pass to the five digits and are in- 

 serted into the bases of the terminal 

 phalanges. Those of the first four digits 

 perforate the tendon of the flexor sublimis 

 (/') at the base of the first phalanx of each 

 digit. yVt the same place each passes 

 through a fibrous pulley-ring attached to 

 the base of the phalanx. Each then passes 

 through a second pulley-ring (2) near the 

 head of the phalanx and is finally inserted 

 into the base of the terminal phalanx. 



Relations. — Outer surface with the 

 pronator teres (Fig- 77, q), flexor carpi 

 radialis (Fig. 77, /'), palmaris longus {s), 

 flexor carpi ulnaris (/), integument, and 

 extensor carpi ulnaris (Fig. 75, o). Inner 

 surface with the radius, ulna, interosseous 

 membrane and pronator quadratus (Fig. 

 87, a). 



Action.- — Flexor of all the digits. 



M. pronator quadratus (Fig. 87, a). 



A thick quadrangular muscle whose its tendons) have been re- 



-, 1 1- 1 1 1 !• 1 moved; the flexor sublimis 



fibres run obliquely between the distal has been cut. a, cut ends 

 ends of the ulna and radius. ff tendons of M. palmaris 



longus; 0. tendons of M. 



Origin by fleshy fibres from about the flexor sublimis digitorum, 

 distal half of the ventral (flexor) surface "'"f fttT ''''" if'""^ 



^ ' part 01 M. nexor sublimis 



or border of the ulna and from the interos- digitorum; c, tendons of 



1 !• i. i i.1 M. flexor profundus digi- 



seous membrane adjacent to the area, torum (.', the common ten- 

 The fibres pass obliquely distad toward ^owy, d, M. abductor digi- 



,. !• 1 • 1 , ,1 • ti nuinti; I?, M. flexor brevis 



the radial side to their ^ligiti quinti;/, Mm. lum- 



Insertion by fleshy fibres into the ven- bricaiesf/', their tendons). 



,-i. transverse ligament of 

 tral (flexor) surface of the radius distad of wrist; 2, annular ligaments. 



the area of origin of the fifth head of the profundus. 



Fig. 88. — Arrangement 

 OF THE Tendons of 

 M. palmaris longus, M. 

 flexor sublimis digito- 

 rum, and M. flexor pro- 

 fundus digitorum, with 

 Mm. lumbricales. 

 The integument, fibrous 

 pads, and the palmaris 

 longus (except the ends of 



