Download Nerves of Forearm LO6

Nerves of Forearm LO6
6. Apply principles NP3, NP6 & NP7 to describe the course and distribution of the following
nerves median, anterior interosseous, ulnar, radial, posterior interosseous and superficial
branch of radial. On the basis of the course of each nerve identify potential sites for injury in the
forearm.
For any structure passing through the forearm you should be able to talk about its
relationships to other structures it travels through or with!
Median Nerve
Course:
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Enters cubital fossa with brachial artery
Exits by passing between heads of pronator teres
Passes between FDS and FDP as it travels down
forearm
Enters carpal tunnel as it passes under the flexor
retinaculum
Branches:
Muscular branch: innervates all superficial and
intermediate anterior compartment muscles except FCU
and medial half of FDP. Major nerve of anterior
compartment of forearm.
Palmar Cutaneous branch: innervates skin of lateral 3
digits and ½ of 4th digit.
Anterior interosseous nerve:
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Ulnar Nerve
Major branch of median nerve in forearm
Travels with the anterior interosseous branch of the
ulnar artery
Innervates the deep muscles of the anterior
compartment of the forearm except the medial half
of FDP.
Course:
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Between the medial epicondyle of humerus and
olecranon process of ulnar
Travels between FCU and FDP
Travels with ulnar artery and vena comitantes
Branches:
Muscular: only innervates FCU and medial half of
FDP.
Articular: elbow and wrist joints.
Cutaneous: palmar branches to digit 5 and ½ of digit 4
on both the palmar and dorsal surface of the hand.
Vascular: ulnar artery.
Radial Nerve
Course:
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Sneaks in the cubital fossa laterally from posterior compartment of arm.
Divides into two branches (deep and cutaneous) as soon as it enters cubital fossa.
Deep branch pierces the supinator and descends into the posterior compartment of the arm where it
is referred to as the posterior interosseous branch.
The superficial branch travels with the brachioradialis.
Branches:
The superficial branch of the radial nerve:
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Cutaneous branch
Gives rise to articular branches as well.
Distributed to skin on the dorsum of the hand
Branching soon after the radial nerve pierces the intermuscular septum into the anterior
compartment of the arm
Crosses the roof of the anatomical snuff box
Posterior interosseous nerve (deep branch of radial nerve)
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Also known as deep branch of the radial nerve
Pierces the supinator
Runs between superficial and deep extensor muscles with the posterior interosseous artery (from
ulnar artery)
Supplies motor innervation to the muscles of both the deep and superficial posterior
compartments of the arm
The posterior cutaneous nerve of the forearm:
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Arises from the radial nerve in the posterior compartment of the arm
Runs along the radial groove of the humerus
Reaches the forearm independent of the radial nerve
descending in the subcutaneous tissue of the posterior aspect of the forearm to the wrist, supplying
the skin