Anterior Compartment of the Forearm
subsequently enters the palm to form the
deep palmar arch (Fig. 3.54). In the forearm,
the artery gives branches to muscles and
contributes to anastomoses around the
elbow and wrist joints. Near the wrist, the
radial artery is close to the cephalic vein.
These vessels may be joined surgically to
form an arteriovenous fistula for easy
vascular access in patients undergoing
renal dialysis.
The ulnar artery passes deep to the arch
formed by the radial and ulnar attachments of flexor digitorum superficialis and
continues between the superficial and deep
flexor muscles. In the distal part of the
forearm, the artery is accompanied on its
medial side by the ulnar nerve. It lies
beneath flexor carpi ulnaris but at the wrist
emerges to lie lateral to the tendon of this
muscle, where its pulse can be palpated.
The ulnar artery crosses superficial to the
flexor retinaculum and, as it enters the
hand, divides into superficial and deep
palmar branches. The ulnar artery gives
branches to the muscles of the anterior
compartment and to the anastomoses
around the elbow and wrist joints. Its
largest branch, the common interosseous
artery (Fig. 3.36), arises near the origin
of the ulnar artery and promptly divides
into posterior and anterior interosseous
89
branches. The posterior interosseous artery
enters the posterior interosseous compartment of the forearm (Fig. 3.77). The larger
anterior interosseous artery passes distally
in the anterior compartment, lying on the
interosseous membrane, accompanied by
the anterior nerve. The vessel supplies the
deep flexor muscles and gives nutrient
branches to the radius and ulna. Distally,
it penetrates the interosseous membrane to
assist in the anastomoses around the wrist.
The patency of the ulnar and radial arteries
and of the palmar arches can be assessed
using Allen’s test. After compression of
both arteries, release of one artery should
be followed within a few seconds by flushing of the whole hand. The compression is
then repeated and followed by release of
the other artery. Incomplete or slow flushing suggests poor blood flow through one
of the arteries or its branches.
Venae comitantes accompany the arteries of the anterior compartment and drain
proximally into veins around the brachial
artery.
Nerves
Fused tendons
of superficial
flexors (cut)
Brachioradialis
(cut)
Tendon of
biceps brachii (cut)
Supinator
Flexor pollicis
longus
Flexor digitorum
profundus
Tendon of
brachioradialis
(cut)
Copyright © 2016. Elsevier. All rights reserved.
Tendon of flexor
carpi ulnaris (cut)
Tendon of
flexor carpi
radialis (cut)
Lumbricals
Tendons of flexor
digitorum
superficialis
(cut)
S
la
m
I
Fig. 3.35 Flexor digitorum profundus and
flexor pollicis longus exposed by removal of
the superficial flexors. As in this specimen, the
index component of flexor digitorum profundus
is often separate from the rest of the muscle.
The median nerve enters the forearm from
the cubital fossa between the two heads of
pronator teres. It crosses anterior to the
ulnar artery (Fig. 3.36) and descends
between the superficial and deep flexors.
At the wrist, the median nerve is remarkably superficial, lying medial to the tendon
of flexor carpi radialis and just deep to the
palmaris longus tendon. The median nerve
passes through the carpal tunnel into the
hand, where it divides into terminal
branches (Fig. 3.52). The nerve supplies all
the superficial muscles of the anterior compartment except flexor carpi ulnaris. The
anterior interosseous branch of the median
nerve (Fig. 3.36) supplies all the deep
muscles of the compartment except the
medial part of flexor digitorum profundus.
This branch lies between flexor digitorum
profundus and flexor pollicis longus and
passes behind pronator quadratus to
supply the wrist (Fig. 3.33). In the forearm,
the median nerve also gives a palmar cutaneous branch, which crosses superficial to
the flexor retinaculum and supplies skin of
the lateral part of the palm. Superficial lacerations near the wrist may damage the
palmar cutaneous branches but leave the
median and ulnar nerves intact. Testing
Gosling, John A., et al. Human Anatomy, Color Atlas and Textbook E-Book : Human Anatomy, Color Atlas and Textbook E-Book, Elsevier, 2016. ProQuest Ebook Central,
http://ebookcentral.proquest.com/lib/soton-ebooks/detail.action?docID=4595632.
Created from soton-ebooks on 2025-02-01 12:51:46.