Arcuate nucleus (medulla)

This article is about the structure in the medulla oblongata. For the hypothalamic structure, see Arcuate nucleus (hypothalamus).

In the medulla oblongata, the arcuate nucleus is a group of neurons located on the anterior surface of the medullary pyramids. These nuclei are the extension of the pontine nuclei.^[1]

Arcuate nucleus (medulla)
Transverse section of medulla oblongata below the middle of the olive. ("Nucleus arcuatus" visible near bottom right.)
Dissection of brain-stem. Lateral view. (Labels for "External arcuate fibers" and "Dorsal external arcuate fibers" visible at lower right.)
Details
Identifiers
Latin	nucleus arcuatus medullae oblongatae
NeuroNames	775
NeuroLex ID	birnlex_2635
TA98	A14.1.04.256
TA2	6016
FMA	72609
Anatomical terms of neuroanatomy [edit on Wikidata]

They receive afferents from the corticospinal tract.^{[citation needed]}

They in turn project efferents into the cerebellum through the inferior cerebellar peduncle as:^[1]

• the anterior internal arcuate fibers which pass along the midline before decussating near the rhomboid fossa (floor of fourth ventricle) then passing laterally as the medullary striae;
• the anterior external arcuate fibers.

Function

Arcuate nuclei are capable of chemosensitivity and have a proven role in the respiratory center controlling the breathing rate.^[2]

Additional images

• 
  Diagram showing the course of the arcuate fibers.
• 
  The formatio reticularis of the medulla oblongata, shown by a transverse section passing through the middle of the olive.

External links

• MedEd at Loyola Neuro/frames/nlBSs/nl31fr.htm
• PubMed article