The superficial branch of the

radial nerve The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial comp ...

passes along the front of the radial side of the

forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anat ...

to the commencement of its lower third. It is a sensory nerve. It lies at first slightly lateral to the radial artery, concealed beneath the

Brachioradialis The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way o ...

. In the middle third of the forearm, it lies behind the same muscle, close to the lateral side of the artery. It quits the artery about 7 cm. above the wrist, passes beneath the tendon of the Brachioradialis, and, piercing the deep fascia, divides into two branches: lateral and medial.

Structure

Lateral branch

The ''lateral branch'', the smaller, supplies the radial side of the thumb (by a digital nerve), the skin of the radial side and ball of the thumb, joining with the volar branch of the

lateral antebrachial cutaneous nerve The lateral antebrachial cutaneous nerve (or lateral cutaneous nerve of forearm) (branch of musculocutaneous nerve, also sometimes spelled "antebrachial") passes behind the cephalic vein, and divides, opposite the elbow-joint, into a volar and a ...

Medial branch

The ''medial branch'' communicates, above the wrist, with the dorsal branch of the lateral antebrachial cutaneous, and, on the back of the hand, with the dorsal branch of the

ulnar nerve In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is ...

. It then divides into four digital nerves, which are distributed as follows: the first supplies the ulnar side of the thumb; the second, the radial side of the

index finger The index finger (also referred to as forefinger, first finger, second finger, pointer finger, trigger finger, digitus secundus, digitus II, and many other terms) is the second digit of a human hand. It is located between the thumb and the mid ...

; the third, the adjoining sides of the index and middle fingers; the fourth communicates with a filament from the dorsal branch of the ulnar nerve, and supplies the adjacent sides of the middle and ring fingers.

Clinical significance

The superficial branch of radial nerve is associated with an entrapment neuropathy called Wartenberg's syndrome. The nerve may be compressed due to wearing a tight wristband, watch or bracelet.

Additional images

File:Gray528.png, Ulnar and radial arteries. Deep view. File:Gray815.png, Superficial palmar nerves. File:Gray817.png, Deep palmar nerves. File:Gray1235.png, Front of right upper extremity, showing surface markings for bones, arteries, and nerves.

References

External links

* * * {{Authority control Nerves of the upper limb