Cranial nerve nucleus

Brain: Cranial nerve nucleus
The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue. (The olfactory and optic centers are not represented.)
Latin	nucleus nervi cranialis
Gray's	subject #195 881

A cranial nerve nucleus is a collection of neurons (gray matter) in the brain stem that is associated with one or more cranial nerves. Axons carrying information to and from the cranial nerves form a synapse first at these nuclei. Lesions occurring at these nuclei can lead to effects resembling those seen by the severing of nerve(s) they are associated with. All the nuclei except that of the IV nerve supply nerves of the same side of the body.

Contents 1 Arrangement of the nuclei 2 Examples of nuclei 2.1 hindbrain (rhombencephalon) 2.1.1 medulla oblongata 2.1.2 pons 2.2 midbrain (mesencephalon) 3 References 4 Additional images 5 External links

Arrangement of the nuclei

Just as grey matter in the ventral (closer to front of a human) spinal cord tends to be efferent (motor) fibers, and the dorsal horn tends to contain afferent (sensory) neurons, nuclei in the brainstem are arranged in an analogous way.

• Close to the midline are the motor efferent nuclei, such as the oculomotor nucleus, which control skeletal muscle. Just lateral to this are the autonomic (or visceral) efferent nuclei.

• There is a separation, called the sulcus limitans, and lateral to this are the sensory nuclei. Near the sulcus limitans are the visceral afferent nuclei, namely the solitary tract nucleus.

• More lateral, but also less posterior, are the general somatic afferent nuclei. This is the trigeminal nucleus. Back at the dorsal surface of the brainstem, and more lateral are the special somatic afferents, this handles sensation such as balance.

• Another area, not on the dorsum of the brainstem, is where the branchial efferent nuclei reside. These formed from the branchial arches, in the embryo. This area is a bit below the autonomic motor nuclei, and includes the nucleus ambiguus, facial nerve nucleus, as well as the motor part of the trigeminal nerve nucleus.

Examples of nuclei

There are several cranial nerve nuclei (roman numeral refers to the cranial nerve number):

hindbrain (rhombencephalon)

medulla oblongata

• Hypoglossal nucleus (XII) - motor
• Dorsal motor nucleus of vagus nerve (X) - visceromotor
• Nucleus ambiguus (IX, X, XI) - motor
• Solitary nucleus (VII, IX, X) - sensory
• Spinal trigeminal nucleus (V) - sensory (crude touch, temperature and pain)
• Inferior olivary nucleus afferent fibres to cerebellum

pons

• Cochlear nuclei (VIII) - sensory
  • Dorsal cochlear nucleus
  • Ventral cochlear nucleus
• Vestibular nuclei (VIII) - sensory
• Salivary nuclei - visceromotor
  • Inferior salivary nucleus (IX)
  • Superior salivary nucleus (VII)
• Facial nucleus (VII) - motor
• Abducens nucleus (VI) - motor
• Trigeminal motor nucleus (V) - motor
• Main trigeminal nucleus (V) - sensory (fine touch and vibration)

midbrain (mesencephalon)

• Mesencephalic trigeminal nucleus (V) - sensory
• Red nucleus - motor, extrapyramidal
• Trochlear nucleus (IV) - motor
• Oculomotor nucleus (III) - motor
• Edinger-Westphal nucleus (III) - visceromotor

References

• Lennart Heimer, The Human Brain, ISBN 0-387-94227-0

Additional images

External links

• Diagrams at McGill
• Diagram at Washington University
• Atlas of anatomy at UMich n2a6p2
• Slides at Colorado College

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 M: PNS anat(h/r/t/c/b/l/s/a)/phys(r)/devp/prot/nttr/nttm/ntrp noco/auto/cong/tumr, sysi/epon, injr proc, drug(N1B)

Human brain: mesencephalon (midbrain) (TA A14.1.06, GA 9.800) Tectum (Dorsal) Surface Corpora quadrigemina: Inferior colliculi (Brachium of inferior colliculus), Superior colliculi (Brachium of superior colliculus) Grey matter Pretectal area White: Sensory/ascending Spinotectal tract · Central tegmental tract White: Motor/descending Tectospinal tract Peduncle (Ventral) Tegmentum White: Sensory/ascending lemnisci (Medial, Lateral) · Ascending MLF (Vestibulo-oculomotor fibers) · Spinothalamic tract · Anterior trigeminothalamic tract · Dentatothalamic tract White: Motor/descending Rubrospinal tract · Rubro-olivary tract · Descending MLF Grey: cranial nuclei GSA (V: Mesencephalic) - GSE (III: Oculomotor, IV: Trochlear) - GVE (III: Edinger-Westphal) Grey: other Periaqueductal gray/Raphe nuclei (Dorsal raphe nucleus) Ventral tegmental area • Pedunculopontine nucleus • Red nucleus riMLF Ventricular system Cerebral aqueduct Base White: Motor/descending Cerebral crus: Corticospinal tract · Corticobulbar tract · Corticopontine tract/Frontopontine fibers/Temporopontine fibers Grey: Substantia nigra Pars compacta · Pars reticulata Surface Superior cerebellar peduncle (Decussation of superior cerebellar peduncles) · Interpeduncular fossa M: CNS anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

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) M: CNS anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

Human brain: rhombencephalon, myelencephalon: medulla (TA A14.1.04, GA 9.767) Dorsal Surface Posterior median sulcus · Posterolateral sulcus · Area postrema · Vagal trigone · Hypoglossal trigone · Medial eminence Grey: Cranial nuclei afferent: GVA: VII,IX,X: Solitary/tract/Dorsal respiratory group · SVA: Gustatory nucleus · GSA: VIII-v (Lateral, Medial, Inferior) efferent: GSE: XII  · GVE: IX,X,XI: Ambiguus · SVE: X: Dorsal · IX: Inferior salivatory nucleus Grey: other Gracile nucleus · Cuneate nucleus · Accessory cuneate nucleus White: Sensory/ascending Sensory decussation  · Medial lemniscus · Inferior cerebellar peduncle (Juxtarestiform body) · Ascending dorsal longitudinal fasciculus · MLF, III, IV and VI White: Motor/descending Descending dorsal longitudinal fasciculus · MLF, III, IV and VI Ventral White: Motor/descending Motor decussation · Olivocerebellar tract · Rubro-olivary tract Grey matter Ventral respiratory group · Arcuate nucleus of medulla · Inferior olivary nucleus · Rostral ventromedial medulla Surface Anterior median fissure · Anterolateral sulcus · Olive · Pyramid Grey: Raphe/ reticular Reticular formation (Gigantocellular, Parvocellular, Ventral, Lateral, Paramedian) · Raphe nuclei (Obscurus, Magnus, Pallidus) M: CNS anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr proc, drug(N1A/2AB/C/3/4/7A/B/C/D)