The lateral cutaneous nerve of forearm (or lateral antebrachial cutaneous nerve) is a sensory nerve representing the continuation of the

musculocutaneous nerve The musculocutaneous nerve is a Mixed nerve, mixed branch of the lateral cord of the brachial plexus derived from cervical spinal nerves C5-C7. It arises opposite the lower border of the pectoralis minor. It provides motor innervation to the mus ...

beyond the lateral edge of the tendon of the

biceps brachii muscle The biceps or biceps brachii (, "two-headed muscle of the arm") is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Both Muscle head, heads of the muscle arise on the scapula and join to form a single ...

. The lateral cutaneous nerve provides sensory innervation to the skin of the lateral forearm. It pierces the deep fascia of forearm to enter the subcutaneous compartment before splitting into a volar branch and a dorsal branch.

Anatomy

Course and relations

It passes behind the

cephalic vein In human anatomy, the cephalic vein (also called the antecubital vein) is a superficial vein in the arm. It is the longest vein of the upper limb. It starts at the anatomical snuffbox from the radial end of the dorsal venous network of hand, a ...

and divides opposite the

elbow-joint The elbow is the region between the arm, upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the Lateral epic ...

into a volar branch and a

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

branch.

Branches

Volar branch

The volar branch (ramus volaris; anterior branch) descends along the radial border 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 used to describe the entire appendage of the upper limb, but which in anatomy, techn ...

to the wrist, and supplies the skin over the lateral half of its volar surface. At the wrist-joint it is placed in front of the

radial artery In human anatomy, the radial artery is the main artery of the lateral aspect of the forearm. Structure The radial artery arises from the bifurcation of the brachial artery in the antecubital fossa. It runs distally on the anterior part of the ...

, and some filaments, piercing the deep fascia, accompany that vessel to the dorsal surface of the carpus. The nerve then passes downward to the ball of the

thumb The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb ...

, where it ends in cutaneous filaments. It communicates with 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 compartment of the ...

, and with the palmar cutaneous branch of the

median nerve The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus. The median nerve originates from the lateral and medial cords of the brachial plexus, and has cont ...

Dorsal branch

The dorsal branch (ramus dorsalis; posterior branch) descends, along the dorsal surface of the radial side of the forearm to the

wrist In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...

. It supplies the skin of the lower two-thirds of the dorso-lateral surface of the forearm, communicating with the superficial branch of the radial nerve and the posterior cutaneous nerve of forearm of the radial nerve.

Additional images

File:Gray413_color.png, Cross-section through the middle of upper arm. File:Gray417_color.PNG, Cross-section through the middle of the forearm.

References

External links

* * , * * - "Cutaneous nerves of the upper extremity." * {{Authority control Nerves of the upper limb