102 LABORATORY MANUAL OF HUMAN ANATOMY 



Study the ligaments of the sheaths of the fingers (ligamenta 

 vaginalia digitorum manus} and the accessory ligaments. Of the 

 latter, examine (1) the ring-ligaments (ligamenta annularia digi- 

 torum manus) and (2) the cruciate ligaments (ligamenta cruciata 

 digitorum manus). (Spalteholz, Fig. 363.) 



Cut through these ligaments and open up the digital sheaths of 

 the tendons. The vincula tendinum are well seen on raising the 

 tendons from the phalanges. 

 (d) Flexor tendons and their insertions. (Fig. 38.) 



Cut through the ligamentum carpi transversum by a vertical 

 incision at its middle, thus opening the carpal canal (canalis carpi). 

 Examine the arrangement of the flexor tendons and dissect each 

 free from the vagina tendinum. Compare the arrangement found 

 with the description in your systematic text-book. Note the rela- 

 tion of these tendons to the central compartment of the palm. 



Examine carefully the insertions of the tendons of the various 

 flexor muscles. Where and how are the tendons of the superficial 

 flexor perforated by those of the deep flexor? What is meant by 

 the chiasm of the tendons (chiasma tendinum) ? 



FIG. 38. 



Os metacarpale 



Tendon of the M. flexor digitorum subfimis 



M. lumbricalia 



Tendon of the M. flexor 

 digitorum profundus 



The terminal parts of the flexor and extensor tendons of the right middle finger, seen from the radial 

 side. (After Toldt, Anat. Atlas, Wien, 1900, 2 Aufl., p. 323, Fig. 565. ) 



Follow the tendon of the M. flexor pollicis longus. Open the 

 vagina tendinis and see how and where the tendon is inserted. 

 What is its relation to the muscles of the thenar eminence 1 ? 



Lumbrical Muscles (Mm. lumbricales). 



Cut through the arcus volaris superficialis on the ulnar side 

 distal from the deep volar ramus of the ulnar artery, and on the 

 radial side at its junction with the superficial volar ramus of the 

 radial artery. Beflect the arch distalward. Cut through the 

 N. medianus at the level of the wrist and reflect it radialward and 

 distalward, noting again its branches to the muscles of the thenar 

 eminence and the two (radial) Mm. lumbricales. Cut through 

 the M. flexor digitorum sublimis at middle of forearm and reflect 

 it and its tendons distalward as far as possible. Examine thor- 

 oughly the tendons of the M. flexor digitorum profundus and the 



