Solitary nucleus
From Wikipedia, the free encyclopedia
| Brain: Solitary nucleus | ||
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| The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue. | ||
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| Transverse section of medulla oblongata of human embryo. | ||
| Latin | tractus solitarius medullae oblongatae | |
| NeuroNames | hier-739 | |
| MeSH | Solitary+Nucleus | |
| Dorlands/Elsevier | t_15/12817166 | |
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).
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[edit] Anatomy
The nucleus is located along the length of the medulla (with a small portion in the lower pons). The solitary tract runs in the middle of the nucleus, creating a speck of white matter (axons of the tract), surrounded by grey matter (the nucleus). This stands out on a stained section, which is where the name solitary comes from.
The solitary nucleus is divided into a rostral (towards the top) gustatory nucleus and caudal (towards the bottom) cardiorespiratory nucleus. The cardiorespiratory nucleus can be further divided into a cardiovascular center, which sits at the midline of the nucleus, and a respiratory center, which is located laterally.
[edit] Inputs to the solitary nucleus
In addition to afferent taste information from nerves VII, IX and X, the solitary nucleus also handles signals from the carotid (via IX) and aortic bodies (via X). Neurons that synapse in this nucleus mediate the gag reflex, the carotid reflex, the aortic reflex, the cough reflex, the baroreceptor and chemoreceptor reflexes, and several respiratory reflexes. Information about the gut wall, as well as stretch of the lungs and dryness of mucous membranes, also synapses at the solitary nucleus.
[edit] Outputs from the solitary nucleus
Most information goes from the solitary nucleus to the hypothalamus and cingulate gyrus, as well as to other nuclei in the brainstem (such as visceral motor or respiratory centers).
[edit] Additional images
 Section of the medulla oblongata at about the middle of the olive. |
 Nuclei of origin of cranial motor nerves schematically represented; lateral view. |
 Primary terminal nuclei of the afferent (sensory) cranial nerves schematically represented; lateral view. |
