The posterior auricular nerve is a nerve of the head. It is a branch of the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste ...

(CN VII). It communicates with branches from the

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...

, the

great auricular nerve The great auricular nerve is a cutaneous nerve of the head. It originates from the cervical plexus, with branches of spinal nerves C2 and C3. It provides sensory nerve supply to the skin over the parotid gland and the mastoid process of the tempor ...

, and the

lesser occipital nerve The lesser occipital nerve or small occipital nerve is a cutaneous spinal nerve. It arises from second cervical (spinal) nerve (along with the greater occipital nerve). It innervates the scalp in the lateral area of the head posterior to the ...

. Its auricular branch supplies the

posterior auricular muscle The posterior auricular muscle is a muscle behind the auricle of the outer ear. It arises from the mastoid part of the temporal bone, and inserts into the lower part of the cranial surface of the auricle of the outer ear. It draws the auricle ...

, the intrinsic muscles of the auricle, and gives sensation to the auricle. Its occipital branch supplies the occipitalis muscle.

Structure

The posterior auricular nerve arises from the

(CN VII). It is the first branch outside of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

. This origin is close to the stylomastoid foramen. It runs upward in front of the

mastoid process The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles (via tendons) and it has openings for blood vessels. From its borders, ...

. It is joined by a branch from the auricular branch of the

(CN X). It communicates with the posterior branch of the

, as well as with the

. As it ascends between the

external acoustic meatus The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter. Struct ...

and mastoid process it divides into auricular and occipital branches. * The ''auricular branch'' travels to the

and the intrinsic muscles on the cranial surface of the auricule. * The ''occipital branch'', the larger branch, passes backward along the

superior nuchal line The nuchal lines are four curved lines on the external surface of the occipital bone: * The upper, often faintly marked, is named the highest nuchal line, but is sometimes referred to as the Mempin line or linea suprema, and it attaches to the epi ...

of the occipital bone to the occipitalis muscle.

Function

The posterior auricular nerve supplies the

, and the intrinsic muscles of the auricle. It gives sensation to the auricle. It also supplies the occipitalis muscle.

Clinical significance

Nerve testing

The posterior auricular nerve can be tested by contraction of the occipitalis muscle, and by sensation in the auricle. This testing is rarely performed.

Biopsy

The posterior auricular nerve can be biopsied. This can be used to test for

leprosy Leprosy, also known as Hansen's disease (HD), is a long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the nerves, respiratory tract, skin, and eyes. This nerve damag ...

, which can be important in diagnosis.

References

External links

* () * () * http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-5.HTM {{Authority control Facial nerve