9O Anatomy Applied to Medicine and Surgery. 



median and ulnar nerves; (3) vaginal sheaths, composed 

 of transverse fibres, which arch from one side of a phalanx 

 to the other, and thus form channels for the flexor ten- 

 dons of the fingers. Inside of these channels and between 

 their walls and the tendons are (4) closed sheaths of syn- 

 ovial membrane, while, passing from the parietal layer of 

 the synovial sheath to the layer enclosing the tendon, are 

 short reflections of synovial membrane termed "vincula 

 vasculosa." These reflections carry small branches from 

 the collateral digital arteries to the tendons for the purpose 

 of nourishing them. On the back of the fingers are (1) 

 skin, and (2) superficial fascia, with dorsal digital arteries 

 and branches of the radial and ulnar nerves. Beneath 

 this fascia are (3) the expansions of the extensor tendons. 



Examining the above structures in detail and begin- 

 ning with those of the palm we find : (1) That the integu- 

 ment of the palm of the hand is bound firmly down to the 

 deep palmar fascia, by means of the superficial palmar 

 fascia, and that this superficial fascia is composed of nu- 

 merous inelastic fibres which cross one another in various 

 directions and, between which, are lodged pellets of fat. 

 The integument is so firmly held down to the palmar fas- 

 cia by these inelastic fibres that very little retraction oc- 

 curs in a wound of the palm, nor, is there much swelling 

 permitted in inflammatory conditions of this part, al- 

 though the pain is generally severe. 



(2) The annular ligament, attached to the pisiform 

 bone and the hook of the unciform internally, and to the 

 tuberosity of the scaphoid and the ridge of the trapezium 

 externally, is thick and strong, and has the ulnar nerve, 

 the ulnar artery, the cutaneous branches of ulnar and me- 

 dian nerves, and the palmaris longus tendon in front of it. 

 It bridges over the depression on the front of the upper 

 part of the palm, thus forming a channel for the passage 



