302 A MANUAL OF ANATOMY. 



palmar fascia to the thumb, which, though thin and not so 

 easily demonstrated as the four internal ones, still can be 

 shown to have a similar arrangement to them, and to be 

 attached to the ligaments and fibrous structures about 

 the metacarpophalangeal articulation. Between the divided 

 fasciculus the tendon of the long flexor passes. The 

 palmaris brevis muscle lies superficial to the inner portion 

 of the inner or hypothenar fascia. 



At the extreme web of the fingers exists a more or less 

 distinct band of transverse fibres (fibres of Gerdy), which 

 serve to bind together the fingers and strengthen the hand. 



The digital vessels will be found between the fasciculi of 

 the palmar fascia, and their position with reference to the 

 bones of the fingers is to be noted. 



DISSECTION. 



Remove the lateral portions of the palmar fascia, with the inner the palmaris 

 brevis muscle, and the central portion in the following way : Draw down- 

 ward on the tendon of the palmaris longus muscle and cut it and the fascia 

 carefully away from the annular ligament. When the lower border of the 

 annular ligament is passed, raise all of the central portion of the palmar fascia 

 and separate it from the vessels and nerves beneath. When the attachments 

 of the fasciculi are reached, notice how they split for the transmission of the 

 flexor tendons, while the lumbricales and the digital vessels and nerves occupy 

 the space between the fasciculi themselves. Then divide the fasciculi and 

 remove the fascia entirely. 



Trace the superficial palmar arch, digital vessels, and nerves. Clean the 

 sheath of one or more of the long flexor tendons of the fingers. Notice how 

 the sheath is reinforced by oblique and transverse cross-bands of fibres, then 

 open it. 



Examine the attachments of the anterior annular ligament. 



The muscles of the thumb and little finger are to be divested of their con- 

 nective-tissue covering. 



The Anterior Annular Ligament of the Wrist. Fig. 66. 



This is a dense band of fibres reaching from the base of 



the thumb (scaphoid and trapezium) across the front of the 



