Radial Nerve: What It Is, Where It Passes, And Functions
Greets. Bend your wrist. Spread your fingers. You probably could have done it easily. And this is because your brain has sent the relevant information to the muscles of the arm, wrist and hand to do so. This transmission has been carried out thanks to a series of nerves, which connect the rest of the nervous system with the muscles. One of them, of great importance for the movement and sensitivity of the extremities, is the radial nerve It is about this nerve that we are going to talk about below.
One of the most important bundles of nerve fibers in the control of the upper extremities is called the radial nerve, being a peripheral nerve of the autonomic nervous system
It is one of the three main nerves that innervate the upper extremities, along with the ulnar and median nerves
The radial nerve innervates such relevant muscles as the triceps or anconeus, or the brachialis and brachioradialis. Also, among others, the extensors of the fingers, including the index and thumb. It is therefore a nerve of great relevance for human beings. But not only that, it also has connections with the cutaneous nerves and allows sensitivity and tactile perception in the area it innervates.
Areas through which it passes and its two main branches
The nerve in question arises in the brachial plexus, just behind the axillary artery After that he proceeds to pass through the armpit and then down the arm and forearm, hands and fingers. It must also be taken into account that there are two radial nerves, one in each of the halves of the body.
It passes through the anterior compartment of the arm, passing around the spiral groove of the humerus (whose breakage could affect the nerve) and after that it crosses the elbow and reaches the forearm, where it will divide into a superficial branch and a deep branch.
The deep branch passes through the supinator muscle, entering the forearm and reaching the wrist from the back. This branch is linked to muscle perception and the tension and extension capacity of the innervated muscles.
The superficial branch of the radial nerve acts at the level of the skin, affecting the sensitivity of the upper extremities This is subdivided into three cutaneous nerves: posterior of the arm, posterior of the forearm and lateral of the arm. It also comes handy. This branch allows cutaneous perception of the back of the forearm, the upper arm, the back of the hand, and the first four fingers.
Functions of this nerve
Our arms and especially our hands are fundamental elements for human beings since thanks to them we can carry out a large number of activities, from defending ourselves or eating to developing complex instruments and technologies. Its control is therefore of great relevance.
The functions of the radial nerve in this sense are very extensive, and highlights the interesting fact that plays a role in both sensory perception and motor control
At a sensory level, it allows sensitivity and perception of the back of the arm and forearm, including elbows and wrists, as well as part of the hand (specifically it allows sensitivity of the back of the hand) and a large part of the fingers (except little finger and part of the ring finger).
At a motor level it allows the extension of the fingers, wrist and arm. Its action is especially relevant in the posterior forearm by innervating the muscles of the posterior compartment (which allows the wrist and fingers to be extended) and the upper arm (by innervating the triceps brachii).
Injuries to the radial
Looking at the functions of this nerve in general, it can be easy to guess the effects that its injury can have: loss of sensitivity in a large part of the back of the arm, on the back of the hand and even in the fingers and the loss of the city to make a lot of moves
If this nerve is injured at the armpit level, the ability to extend the arm, wrist or fingers is lost, leaving the triceps and the rest of the innervated muscles paralyzed, as well as the lack of tactile perception of a large part of the arm and the back of the hand.
If the injury occurs at the level of the humerus, there will be a decrease in the strength of the triceps and the wrist and fingers will no longer be able to extend and the perception of the back of the hand, wrist and back of the forearm will disappear. Also commonly called wrist drop, which results in loss of coordination and difficulties closing the hand.
If the injury occurs at the level of the superficial branch, the ability to move throughout the area will remain intact, but the sensitivity of the wrist, hand and fingers will be lost.
These alterations can occur due to a large number of factors, and occur either due to lacerations and injuries, impingements or problems in myelination Examples of elements that can cause them are neuropathies such as diabetes, fractures of the humerus or radius, dislocations, poisoning, pressure on the wrist, continued incantation and lack of movement or inflammation.
