THE FOREARM AND HAND. 1205 
under cover of the supinator longus. The ulnar nerve can be rolled beneath the 
finger upon the back of the internal condyle ; its position renders it lable to injury 
in severe fractures about the 
elbow, and in excising the joint 
care must be taken not to Brachialie snuigue 
injure the nerve. ae Gelli caret _ Brachial artery 
x 1ceps—— c 
Basilie vein 
— Brachialis anticus 
eae atihile hh 
THE FOREARM AND HAND. 
Median cephalic vein 
The upper half of the radius 2 eae 
‘ Tendon of biceps—— 
is deeply placed ; the lower halt Musculo-spiral nerve—— 
is, however, easily palpated. 
The anterior border of its lower 
Median basilic 
vein 
Bicipital fascia 
Posterior interosseous 
extremity is felt as a prominent ecven 
transverse ridge, situated 1 in. 
above the “enone eminence ; Supinator longus 
unmediately below the ridge 
is the radio-carpal articulation. 
The tip of the styloid process, Radial nerve- F 
situated nearly $ in. lower than i 
that of the ulna, is deeply | 
placed at the outer side of the Ce ee 
wrist, in the hollow between wees Uo 
the extensor tendons of the 
first and second phalanges of 
the thumb. Upon the middle 
of the posterior surface of the 
lower end of the radius is the | saexor carn: 
dorsal radial tubercle which ~~ radial 
intervenes between the extensor P"*? f styled process ——~Fgg~ 
of the second phalanx of the 
thumb and the short radial 
extensor of the wrist; the 
tubercle can be distinctly felt, 
and may be taken as a guide 
to the upper end of Lister’s 
dorso-radial incision for excision 
of the wrist. The posterior oF 
border of the ulna is subcu- Deep palmar arch” 
taneous throughout, and may 
be felt along the interval be- 
tween the flexor and extensor 
carpi ulnaris muscles. Upon 
the ulnar side of the dorsal 
aspect of the wrist is a well- 
marked rounded prominence Fic. 812.—BEND OF ELBOW, FRONT oF FOREARM, AND PALM 
OF HAND. 
formed by the lower extremity 
of the ulna, anterior to which is the styloid process, the deep groove between the 
two being occupied by the tendon of the extensor carpi ulnaris. 
The carpal bones are built up so as to form an arch, converted by the anterior 
annular ligament into a tunnel for the transmission of the flexor tendons. At each 
extremity of the arch the two bony points to which the ligament 1s attached 
furnish important landmarks. These bony points are: eaternally, the tubercle of the 
secaphoid and the ridge of the trapezium; internally, the pisiform and the hook of 
the unciform. The tubercle of the scaphoid is felt immediately above the root of 
the thenar eminence, midway between Bie tendons of the extensor ossis metacarpi 
pollicis and the flexor carpi radialis; $ in. below the tubercle of the scaphoid is 
- the ridge of the trapezium, felt ete beneath the inner part of the thenar 
eminence. At the root of the hypothenar eminence, and crossed by the crease 
Ulnar nerve 
Ulnar artery 
y¥———- Median nerve 
Flexor carpi 
~ ulnaris 
_ Flexor sublimis 
digitorum 
non rTM eT 
Pisiform bone 
Radial artery—- Anterior annular 
ligament 
__ Superficial 
palmar arch 
