i6o 



PRACTICAL AX ATOMY. 



centre of the dense ligauicnta vaginalcs and you will come down on the two 

 flexor tendons. Notice that the tendon of the flexor profundns digltontm passes 

 through a slit in the tendon of the flc.wr snblimis digitorum. (Fig. i 10.) The 

 former is inserted into the base of the third, the latter into the base and sides of 

 the second phalanx. Now gently separate these tendons and you will see (i) 

 the visceral layer of synovial membrane on the tendons, and (2) the vincula 

 delicate tendinous cords. 



Extensor oasis metacarpi pollicis 

 Flexor carpi radialis 

 Extensor brevis pollicis 



Abductor pollic;.i 



Opponens pollieis 



Abductor minimi 



digiti 



Flexor sublimis 

 digitorum 



Flexor profundus 

 digitorum 



V pollicis 



-\ Flexor brevis 



pollicis 



~~- Adductor 

 pollicia 



FIG. ii2. THE DEEPKR MUSCLES OF THE PALM OK THE HAND. 



These heavy, deep fascial sheaths you have just cut through are lined by a 

 synovial vaginal membrane called the theca. In the thumb and little finger these 

 synovial cavities communicate with the ulnar and radial palmar bursae above the 

 annular ligament. (Fig. 107.) 



The thecae for the remaining fingers terminate in thecal culs-de-sac opposite 

 the metacarpo-phalangeal articulations. (Fig. 107.) 



Infection in the thumb and little finger thus is liable to travel . beyond the 

 annular ligament, while in the other fingers it would be arrested at the culs-de-sac. 





