What are the branches of the radial nerve? The radial nerve is one of the major nerves that originate from the brachial plexus, a network of nerves that innervates the upper limb. It is responsible for providing sensation and motor control to various parts of the arm and hand. Understanding the branches of the radial nerve is crucial for diagnosing and treating conditions that affect this nerve, such as nerve injuries or compression syndromes. This article will explore the different branches of the radial nerve and their functions.
The radial nerve originates from the C5, C6, and C7 nerve roots of the brachial plexus. It travels down the arm and branches out to innervate various muscles and skin areas. The main branches of the radial nerve include:
1.
Superficial Branch (Radial Nerve to the Deltoid and Triceps):
The superficial branch is the first branch that arises from the radial nerve. It innervates the deltoid muscle, which is responsible for the abduction of the arm, and the triceps brachii muscle, which extends the elbow. This branch also provides sensory innervation to the skin on the posterior aspect of the upper arm.
2.
Deep Branch (Radial Nerve to the Triceps):
The deep branch of the radial nerve supplies the triceps brachii muscle, which is crucial for extending the elbow joint. This branch is responsible for the motor control of the triceps brachii muscle and does not provide sensory innervation.
3.
Posterior Interosseous Nerve:
The posterior interosseous nerve is a continuation of the radial nerve that travels between the radius and ulna bones in the forearm. It innervates the muscles of the posterior compartment of the forearm, including the extensor carpi ulnaris, extensor digitorum, and extensor pollicis longus muscles. These muscles are responsible for extending the wrist and fingers, as well as abducting the thumb. The posterior interosseous nerve also provides sensory innervation to the skin over the posterior aspect of the forearm and hand.
4.
Superficial Branch to the Extensor Carpi Ulnaris:
This branch arises from the posterior interosseous nerve and innervates the extensor carpi ulnaris muscle. This muscle is responsible for extending the wrist and adducting the little finger. The superficial branch also provides sensory innervation to the skin over the ulnar aspect of the hand and the little finger.
5.
Superficial Branch to the Extensor Digitorum:
The superficial branch to the extensor digitorum arises from the posterior interosseous nerve and innervates the extensor digitorum muscle. This muscle is responsible for extending the fingers. The branch also provides sensory innervation to the skin over the back of the fingers.
6.
Superficial Branch to the Extensor Pollicis Longus:
The superficial branch to the extensor pollicis longus arises from the posterior interosseous nerve and innervates the extensor pollicis longus muscle. This muscle is responsible for extending the thumb. The branch also provides sensory innervation to the skin over the thumb.
In conclusion, the radial nerve is a vital nerve that provides motor and sensory innervation to various parts of the arm and hand. Its branches, including the superficial and deep branches, as well as the posterior interosseous nerve, play a crucial role in maintaining the functionality of the upper limb. Understanding the branches of the radial nerve is essential for diagnosing and treating conditions that affect this nerve, ensuring proper care and treatment for patients with radial nerve-related issues.
