The supraclavicular nerves (descending branches) arise from the third and fourth

cervical nerves A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...

. They emerge beneath the posterior border of the

sternocleidomastoideus The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the acce ...

(sternocleidomastoid muscle), and descend in the posterior triangle of the neck beneath the

platysma muscle The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effe ...

and the deep cervical fascia. Together, they innervate skin over the shoulder. The supraclavicular nerve can be blocked during shoulder surgery.

Branches

The supraclavicular nerves arise from C3 and C4 spinal nerve roots. Near the

clavicle The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the rig ...

, the supraclavicular nerves perforate the fascia and the

to become cutaneous. They are arranged, according to their position, into three groups—anterior, middle, and posterior.

Medial supraclavicular nerve

The medial supraclavicular nerves or ''anterior supraclavicular nerves'' (nn. supraclaviculares anteriores; suprasternal nerves) cross obliquely over the

external jugular vein The external jugular vein receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the retromandibular vein with the posterior auricular vei ...

and the clavicular and sternal heads of the

, and supply the skin as far as the middle line. They furnish one or two filaments to the sternoclavicular joint.

Intermedial supraclavicular nerve

The intermedial supraclavicular nerve ''middle supraclavicular nerves'' (nn. supraclaviculares medii; supraclavicular nerves) cross the

, and supply the skin over the

pectoralis major The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, ...

and

deltoideus The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up o ...

, communicating with the cutaneous branches of the upper intercostal nerves.

Lateral supraclavicular nerve

The lateral supraclavicular nerve or ''posterior supraclavicular nerves''(nn. supraclaviculares posteriores; supra-acromial nerves) pass obliquely across the outer surface of the

trapezius The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports ...

and the

acromion In human anatomy, the acromion (from Greek: ''akros'', "highest", ''ōmos'', "shoulder", plural: acromia) is a bony process on the scapula (shoulder blade). Together with the coracoid process it extends laterally over the shoulder joint. The ac ...

, and supply the skin of the upper and posterior parts of the

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder m ...

Function

The supraclavicular nerves together innervate the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

over the

Clinical significance

A supraclavicular

nerve block Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block (sometimes referred to as simply "nerve block") is a short-term block, ...

is useful when performing surgery on the shoulder, anaesthetising a large area of skin. The supraclavicular nerves are vulnerable during surgery on the

, and must be identified early on in surgeries to reduce the risk of

nerve injury Nerve injury is an injury to nervous tissue. There is no single classification system that can describe all the many variations of nerve injuries. In 1941, Seddon introduced a classification of nerve injuries based on three main types of nerve ...

and

neuroma A neuroma (; plural: neuromata or neuromas) is a growth or tumor of nerve tissue. Neuromas tend to be benign (i.e. not cancerous); many nerve tumors, including those that are commonly malignant, are nowadays referred to by other terms. Neur ...

Additional images

File:Gray784.png, Dermatome distribution of the trigeminal nerve File:Gray811and813.PNG, Cutaneous nerves of right upper extremity. File:Gray812and814.PNG, Diagram of segmental distribution of the cutaneous nerves of the right upper extremity. File:Gray1210.png, Side of neck, showing chief surface markings.

References

External links

* {{Authority control Nerves of the head and neck