Abducens nucleus

Abducens Nucleus

The abducens nucleus is a collection of neuronal cell bodies located in the pons, a part of the brainstem. It is one of the several cranial nerve nuclei that exist within the brainstem, and it is specifically associated with the abducens nerve (cranial nerve VI), which controls the movement of a single muscle, the lateral rectus muscle of the eye.

Anatomy

The abducens nucleus is located in the lower part of the pons, near the midline. It is situated in close proximity to the fourth ventricle, and is immediately beneath the facial nerve nucleus. The neurons of the abducens nucleus are of the lower motor neuron type.

Function

The primary function of the abducens nucleus is to innervate the lateral rectus muscle of the eye. This muscle is responsible for the outward (lateral) movement of the eye, a movement known as abduction. The abducens nucleus achieves this by sending signals down the abducens nerve, which then stimulates the lateral rectus muscle to contract.

Clinical Significance

Damage to the abducens nucleus can result in a condition known as abducens nerve palsy, which is characterized by an inability to move the eye outward. This can result in double vision, as the two eyes are no longer able to align properly. Abducens nerve palsy can be caused by a variety of conditions, including stroke, brain tumor, and multiple sclerosis.

See Also

• Cranial nerve nucleus
• Abducens nerve
• Pons
• Brainstem