Structure and Course of the Abducens Nerve
- The abducens nucleus is located in the pons, on the floor of the fourth ventricle.
- Axons from the facial nerve loop around the abducens nucleus, creating a slight bulge called the facial colliculus.
- Motor axons leaving the abducens nucleus run ventrally and caudally through the pons.
- The abducens nerve emerges from the brainstem at the junction of the pons and the medulla.
- It runs superior to the medullary pyramid and medial to the facial nerve.
- The nerve enters the subarachnoid space when it emerges from the brainstem.
- It runs upward between the pons and the clivus, and then pierces the dura mater to run between the dura and the skull.
- It makes a sharp turn forward to enter the cavernous sinus and runs alongside the internal carotid artery.

Development and Function of the Abducens Nerve
- The human abducens nerve is derived from the basal plate of the embryonic pons.
- The abducens nerve supplies the lateral rectus muscle of the human eye, responsible for outward gaze.
- It carries axons of type GSE, general somatic efferent.

Clinical Significance of the Abducens Nerve
- Damage to the peripheral part of the abducens nerve can cause double vision and limitation of eye movement.
- Partial damage to the abducens nerve can result in weak or incomplete abduction of the affected eye.
- Fractures of the petrous temporal bone and aneurysms of the intracavernous carotid artery can selectively damage the nerve.
- Infarcts affecting the dorsal pons at the level of the abducens nucleus can also affect the facial nerve, producing an ipsilateral facial palsy together with a lateral rectus palsy.
- Various processes such as tumors, strokes, infections, and neuropathies can damage the abducens nerve.

History and Etymology of the Abducens Nerve
- The Latin name for the sixth cranial nerve is nervus abducens.
- The Terminologia Anatomica recognizes two different English translations: abducent nerve and abducens nerve.
- Abducens is more common in recent literature, while abducent predominates in the older literature.
- The United States National Library of Medicine uses abducens nerve in its Medical Subject Heading (MeSH) vocabulary.
- Grays Anatomy (2005) also prefers abducens nerve.

Abducens Nerve in Other Animals and Related Topics
- The abducens nerve controls the movement of the lateral rectus muscle of the eye.
- In most other mammals, it also innervates the musculus retractor bulbi, which can retract the eye for protection.
- Homologous abducens nerves are found in all vertebrates except lampreys and hagfishes.
- This article uses anatomical terminology.
- References: Grays Anatomy 2008, Chummy S. Sinnatamby (2011), Umansky et al. (1991), Özveren et al. (2007), Halo Orthosis Immobilization – Spine – Orthobullets.

Abducens nerve (Wikipedia)

The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocular muscles responsible for outward gaze. It is a somatic efferent nerve.

Abducens nerve
The path of the abducens nerve
Inferior view of the human brain, with the cranial nerves labelled.
Details
From	abducens nucleus
Innervates	lateral rectus muscle
Identifiers
Latin	nervus abducens
MeSH	D000010
NeuroNames	550
TA98	A14.2.01.098
TA2	6283
FMA	50867
Anatomical terms of neuroanatomy [edit on Wikidata]