Brain: Abducens nucleus
The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue. The olfactory and optic centers are not represented. (Abducens nucleus is VI)
Latin	nucleus nervi abducentis
Gray's	subject #187 787
Part of	Pons
Artery	Pontine branches of the Basilar artery
NeuroNames	hier-580
NeuroLex ID	birnlex_1366

The abducens nucleus is the originating nucleus from which the abducens nerve emerges - a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the caudal portion of the pons, medial to the sulcus limitans.

The abducens nucleus along with the internal genu of the facial nerve make up the facial colliculus, a hump at the caudal end of the medial eminence on the dorsal aspect of the pons.

[edit] Clinical significance

Damage to the abducens nucleus causes monocular medial ophthalmoparesis: specifically, loss of the ability to move the ipsilateral eye outward (abduction). This is also seen in damage of the abducens nerve.

In contrast, damage to the area of the nucleus can also result in lateral gaze paralysis: loss of the ability to move either eye in the direction of the side with the lesion. This is due to damage to both the motoneurons and interneurons projecting through the medial longitudinal fasciculus to the contralateral medial rectus neurons.

[edit] Additional images

Nuclei of origin of cranial motor nerves schematically represented; lateral view.	Scheme showing central connections of the optic nerves and optic tracts.	Figure showing the mode of innervation of the Recti medialis and lateralis of the eye.	Axial section of the Brainstem (Pons) at the level of the Facial Colliculus
Vestibulo-ocular reflex	Brain stem sagittal section

[edit] External links

• Brainstem at UWisc 13VNAN
• MedEd at Loyola Neuro/frames/nlBSs/nl27fr.htm
• Template (look for "GSE")
• BrainMaps at UCDavis Abducens nucleus

• NIF Search - Abducens Nucleus via the Neuroscience Information Framework

v • d • e Human brain, rhombencephalon, metencephalon: pons (TA A14.1.05.101-604, GA 9.785) Dorsal/ (tegmentum) Surface Cerebellopontine angle · Superior medullary velum · Sulcus limitans · Medial eminence · Facial colliculus White: Sensory/ascending Trapezoid body/VIII · Trigeminal lemniscus (Dorsal trigeminal tract, Ventral trigeminal tract) · Medial lemniscus · Lateral lemniscus MLF, III, IV and VI: Vestibulo-oculomotor fibers Anterior trigeminothalamic tract · Central tegmental tract White: Motor/descending ICP (Vestibulocerebellar tract) MLF, III, IV and VI: Vestibulospinal tract (Medial vestibulospinal tract, Lateral vestibulospinal tract) Grey: Cranial nuclei afferent: GSA: Principal V/Spinal V · VIII-c (Dorsal, Anterior)/VIII-v (Superior) efferent: SVE: Motor V  · VII · GSE: VI · GVE: VII: Superior salivary nucleus Other grey Apneustic center · Pneumotaxic center (Medial parabrachial nucleus) · Lateral parabrachial nucleus · Superior olivary nucleus · Caerulean nucleus Ventral/ (base) Grey Pontine nuclei White: Motor/descending Corticospinal tract · Corticobulbar tract · Corticopontine fibers MCP (Pontocerebellar fibers) Surface Basilar sulcus Other grey: Raphe/ reticular Reticular formation (Caudal, Oral, Tegmental, Paramedian) · Raphe nuclei (Median)

v • d • e Nerves of head and neck: the cranial nerves and nuclei (TA A14.2.01, GA 9.855) olfactory (AON->I) olfactory bulb · olfactory tract optic (LGN->II) optic chiasm · optic tract oculomotor (ON, EWN->III) superior branch (parasympathetic root of ciliary ganglion/ciliary ganglion) · inferior branch trochlear (TN->IV) no significant branches trigeminal (PSN,TSN,MN,TMN->V) trigeminal ganglion • ophthalmic • maxillary • mandibular abducens (AN->VI) no significant branches facial (FMN,SN,SSN->VII) near origin nervus intermedius • geniculate inside facial canal greater petrosal (pterygopalatine ganglion) · nerve to the stapedius · chorda tympani (lingual nerve, submandibular ganglion) at stylomastoid foramen posterior auricular · suprahyoid (digastric, stylohyoid) · parotid plexus (temporal, zygomatic, buccal, mandibular, cervical) vestibulocochlear (VN, CN->VIII) cochlear (striae medullares, lateral lemniscus) • vestibular (Scarpa's ganglion) glossopharyngeal (NA, ISN, SN->IX) before jugular fossa ganglia (superior, inferior) after jugular fossa tympanic (tympanic plexus, lesser petrosal, otic ganglion) • stylopharyngeal branch • pharyngeal branches • tonsillar branches • lingual branches • carotid sinus vagus (NA, DNVN, SN->X) before jugular fossa ganglia (superior, inferior) after jugular fossa meningeal branch · auricular branch neck pharyngeal branch (pharyngeal plexus) · superior laryngeal (external, internal) · recurrent laryngeal (inferior) · superior cervical cardiac thorax inferior cardiac · pulmonary · vagal trunks (anterior, posterior) abdomen celiac · renal · hepatic · anterior gastric · posterior gastric accessory (NA,SAN->XI) cranial · spinal hypoglossal (HN->XII) lingual branches

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