DISSECTION OF THE UPPER EXTREMI 



aponeurosis palmaris. Note its attachments ulna 

 medialward. Study the relations of its deep and supe 

 faces. What is the canal beneath it called and what stru 

 pass through this canal ? 



Flexor Tendons and their Mucous Sheaths. (Cf. Spalteholz, Fig. 



see.) 



(a) Mucous sheath of common flexor tendons (vagina [mucosa] tendinum 

 Mm. flexorum communium) (0. T. synovia! sheath). 



If uninjured by dissection thus far, insert a blow-pipe into sheath 

 proximal to ligamentum carpi transversum and inflate. Study the 

 exact relations to the flexor tendons in your cadaver and compare 

 with text-book descriptions. (Cf. Fig. 37.) 



FIG. 37. 



Palmar synovial sheaths (vaginae tendinum), normal adult type. (From Poirier et Charpy, Trait6 

 d'Anat. hum., Paris, 1901, 2 ed., t. ii. p. 190, Fig. 147.) 



(b) Mucous sheath of tendon of long flexor of thumb (vagina tendinis M. 



ftexoris pollicis longi). 



(c) Digital sheaths of the tendons (vaginae tendinum digitales). 



Note also the pairs of small folds extending between the first 

 and second phalanges and the digital sheaths; these are the so- 

 called "bands of union of the tendons" (vincula tendinum). They 

 carry the blood-vessels to the tendons. 



