Radial nerve

A crucial nerve that enables movement and sensation in the arm and hand.

The radial nerve is one of the major peripheral nerves of the upper limb. It originates from the brachial plexus, arising from spinal nerves C5 to T1, and plays a vital role in motor and sensory functions. This nerve primarily innervates the muscles of the posterior compartment of the arm and forearm, which are responsible for extension of the elbow, wrist, and fingers.

Terminologia Anatomica

nervus radialis

System

Nervous system

Function

The radial nerve serves multiple essential functions in the upper limb, particularly in facilitating movement and providing sensory feedback. It primarily innervates the triceps brachii muscle, which allows for the extension of the elbow. In the forearm, it supplies muscles that extend the wrist and fingers, enabling actions like grasping and releasing objects. Additionally, the radial nerve has sensory components that relay information from the skin of the posterior arm, forearm, and part of the hand, contributing to the perception of touch, temperature, and pain. By coordinating muscle movements and providing sensory input, the radial nerve plays a pivotal role in many daily activities such as writing, typing, and sports, highlighting its importance in upper limb functionality.

Location

The radial nerve is located in the upper limb and follows a unique path as it travels from the shoulder down to the hand. It begins at the posterior aspect of the brachial plexus and travels along the lateral side of the humerus, crossing over to the posterior compartment, where it runs in the radial groove. As it progresses downward, it innervates muscles in the upper arm before branching into the forearm. It continues its trajectory by passing around the radial head and extends into the wrist, where it divides into superficial and deep branches. The superficial branch primarily carries sensory functions to the back of the hand, while the deep branch is responsible for motor control of the muscles extending the wrist and fingers. This intricate pathway ensures that the radial nerve can effectively influence a broad area of the upper limb.

Did You Know?

The radial nerve is often at risk of injury when individuals experience certain types of fractures, particularly those of the humerus.
Because of its location, symptoms of radial nerve injury can include wrist drop, a condition where the person cannot extend their wrist or fingers.
The radial nerve not only controls motor function but also helps in sensory perception for a significant portion of the hand.