THE BONES OF THE UPPER LIMB 217 



tuberosities of the scaphoid and trapezium externally, and the 

 pisiform and the hook of the unciform internally. These four pro- 

 jections give attachment to the anterior annular Ugament. This 

 ligament, along with the palmar concavity of the carpus, constructs 

 a fibro-osseous passage, called the anterior palmar canal. This 

 canal transmits (i) the tendons of the flexor sublimis, and flexor 

 profundus digitorum, and the median nerve lying within the large 

 inner compartment of the great palmar bursa ; and (2) the tendon of 

 the flexor longus poUicis lying wittiin the small outer cofnpartment 

 of the great palmar bursa. 



The tuberosity of the scaphoid gives partial attachment to the 

 anterior annular ligament, and partial origin to the abductor 

 pollicis muscle. 



The tuberosity of the trapezium, which has the form of a ridge, 

 gives partial attachment to the anterior annular ligament, and 

 partial origin to (i) the abductor pollicis, (2) the opponens pollicis, 

 and (3) the superficial head of the flexor brevis pollicis. 



The groove on the palmar surface of the trapezium transmits the 

 tendon of the flexor carpi radiaHs, which lies in a special compart- 

 ment in the outer part of the anterior annular Ugament, and is 

 invested by a special synovial membrane. 



The pisiform bone gives attachment to (i) part of the anterior 

 annular Ugament, (2) the tendon of the flexor carpi ulnaris, (3) the 

 pisi-uncinate and pisi-metacarpal ligaments, and (4) the abductor 

 minimi digiti muscle. 



The hook of the unciform gives attachment anteriorly to part of 

 the anterior annular Ugament and the pisi-uncinate Ugament, and 

 internally partial origin to the flexor brevis minimi digiti and 

 opponens minimi digiti. The ulnar groove on the internal surface 

 of the hook, close to its root, transmits the deep branches of the 

 ulnar artery and nerve. 



