MhDIAX A.XD ULNAR yKRVES 



r93 



It also supplies a ln'anch to the iiitcrosse(jus ni(.'iul)raiie which runs dowinvurds 

 upon, or in, the membrane sui)plyinff it and giving branches to the anterior inter- 

 osseous and medullary arteries and to the periosteum of the radius and ulna. 



(d) The palmar cutaneous branch arises immediately above the anterior 

 annular ligament and ])asscs Ijetween the tendons of the flexor carpi radialis and 

 the palmaris longus. It then crosses the superficial surface of the annular liga- 

 ment, is distributed to the integument and fascia on the central depressed surface 

 of the palm, and su))])li('s a few twigs to the inmn* border of the thenar eminence; 

 these twigs communicate with the museulo-cutaneous and radial nerves. 



(e) The external terminal division gives oft" a branch which supplies the 

 abductor, the opjtonens, and the superficial head of the flexor brevis pollicis 

 muscles, then it divides into two liranches. The outer branch passes obliquely 

 across the long flexor tendon of tiie thumb, and runs along the radial border of the 



Fig, 45d. — t5UPEBFici.\L Nerves of the P.vlm. (,Ellis.) 



BRASCII TO MU.SCLES 

 OF THUMB 



COLLATERAL 

 BRASCIIES OF 

 MEDIA y 



I I \ \R yERlE 



' o^r^fuyIr AT/OX 



BI rWEES MED I AX 

 1 \D ULXAl: 



COLLATERAL 

 jif / BRANCHES or 



"- I'LXAR 



tlmmb as far as its extremity. It gives numerous branches to the pulj) of the 

 thumb, and a strong twig which passes on to the dorsum to su])ply the matrix of 

 the nail. The inner branch, after running a course varying from an eighth to a 

 half an inch, divides into two digital collateral branches. The outer collateral 

 branch supplies the ulnar side of the volar asi)ect of the thuml), and gives oft' a 

 twig to the matrix of the thumb nail. The inner collateral branch is distributed 

 in a similar manner to the radial side of the index finger. It gives oft' a twig to 

 supply the first lumbrical muscle. 



(./") The internal terminal division divides into an outer and an inner l)ranch. 

 The outer branch gives a twig to supply the second lumbrical muscle, and divides 

 a little above the metacarpo-phalangeal articulation into collateral ])ranches. which 

 supply the adjacent sides of the index and middle fingers, and also give twigs to 

 the dorsum of each of these digits. These dorsal twigs will be more particularly 



