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Encyclopedia > Cranial nerve nuclei
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.)
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Latin '
Gray's subject #195 881
Part of
Components
Artery
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Acronym(s) {{{Acronym}}}
NeuroNames -
MeSH [1]
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A cranial nerve nucleus is a collection of neurons (gray matter) in the brain stem that is associated with one or more cranial nerves. Image File history File links Gray696. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... NeuroNames is a system of nomenclature for the brain and related structures. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo Elsevier, the worlds largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. ... Drawing by Santiago Ramón y Cajal of cells in the pigeon cerebellum. ... Grey matter is a category of nervous tissue with many nerve cell bodies and few myelinated axons. ... The term brain stem (truncus encephali is a Latin synonym) refers to a composite substructure of the brain. ... Cranial nerves are nerves that emerge from the brainstem instead of the spinal cord. ...


As well as the visible nerves outside of the brain, most of the cranial nerves have associated nuclei within the brainstem. These nuclei are areas of grey matter, and damage to them can have a similar affect to the severing of an actual nerve. Axons to (and from) cranial nerves synapse first at the nuclei. In neuroanatomy, a nucleus is a central nervous system structure that is composed mainly of gray matter, and which acts as a hub or transit point for electrical signals in a single neural subsystem. ... Grey matter[1] is a category of nervous tissue with many nerve cell bodies and few myelinated axons. ...

Contents


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 sensory neurons, nuclei in the brainstem are arranged in an analogous way. Cross-section through cervical spinal cord. ... Drawing by Santiago Ramón y Cajal of cells in the pigeon cerebellum. ...

  • Close to the midline are the somatic efferent nuclei, such as the oculomotor nucleus, which control skeletal muscle. Just lateral to this are the autonomic (or visceral) efferent nuclei (for instance, the Edinger-Westphal nucleus, which controls tears).
  • 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.

The oculomotor nerve () is the third of twelve paired cranial nerves. ... The Edinger-Westphal nucleus is the accessory parasympathetic nucleus of the oculomotor nerve, supplying the constricting muscles of the iris. ... The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial (VII), glossopharyngeal (IX), vagus (X) cranial nerves, as well as the cranial part of the accessory nerve (XI). ... The trigeminal nerve is the fifth (V) cranial nerve, and carries sensory information from most of the face, as well as motor supply to the muscles of mastication (the muscles enabling chewing), tensor tympani (in the ear) and other muscles in the floor of the mouth. ... Schematic of developing fetus with first, second and third arches labeled. ... The nucleus ambiguus (literally ambiguous nucleus) is a region of histologically disperse cells located just dorsal (posterior) to the inferior olivary nucleus in the lateral portion of the upper (rostral) medulla. ... The facial nerve is seventh of twelve paired cranial nerves. ... The trigeminal nerve is the fifth (V) cranial nerve, and carries sensory information from most of the face, as well as motor supply to the muscles of mastication (the muscles enabling chewing), tensor tympani (in the middle ear) and other muscles in the floor of the mouth, such as the...

Examples of nuclei

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


hindbrain (rhombencephalon)

Hindbrain has been used to describe several structures found in the brains of vertebrates. ...

medulla oblongata

Position of medulla oblangata in the human brain The medulla oblongata is the lower portion of the brainstem. ... The hypoglossal nucleus extends the length of the medulla, and being a motor nucleus, is close to the midline. ... The nucleus ambiguus (literally ambiguous nucleus) is a region of histologically disperse cells located just dorsal (posterior) to the inferior olivary nucleus in the lateral portion of the upper (rostral) medulla. ... The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial (VII), glossopharyngeal (IX), vagus (X) cranial nerves, as well as the cranial part of the accessory nerve (XI). ... In anatomy, the olivary bodies or simply olives (Latin oliva) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. ...

pons

Position of the pons in the human brain The pons (sometimes pons Varolii after Costanzo Varolio) is a knob on the brain stem. ... The cochlear nuclei consist of: (a) the lateral cochlear nucleus, corresponding to the tuberculum acusticum on the dorso-lateral surface of the inferior peduncle; and (b) the ventral or accessory cochlear nucleus, placed between the two divisions of the nerve, on the ventral aspect of the inferior peduncle. ... The nuclei of the vestibular nerve. ... The Superior salivary nucleus (or superior salivatory nucleus) of the facial nerve is a visceromotor cranial nerve nucleus located in the pontine tegmentum. ... The cranial nerve motor nucleus of the facial nerve is located in the lower pons. ... The abducens nucleus is the originating nucleus from which the abducens nerve emerges - a cranial nerve nucleus. ...

midbrain (mesencephalon)

In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ... The red nucleus is a structure in the rostral midbrain involved in motor coordination. ... The nucleus of the trochlear nerve is located in the midbrain, at the level of the inferior colliculus. ... The oculomotor nerve () is the third of twelve paired cranial nerves. ... The Edinger-Westphal nucleus is the accessory parasympathetic nucleus of the oculomotor nerve, supplying the constricting muscles of the iris. ...

References

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

External links


  Results from FactBites:
 
BRAINSTEM NUCLEI (1859 words)
The cranial nerves (with the exception of I and II) originate in the brainstem, which includes the midbrain, the pons, and the medulla.
Overall, sensory nerve nuclei tend to be located in the lateral brainstem, while motor nuclei tend to be located medially.
Evidence of nerve damage could mean a peripheral lesion in the nerve, or a central lesion in the brainstem.
  More results at FactBites »

 
 

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