Arcuate nucleus (medulla)

{{about|the structure in the medulla oblongata|the hypothalamic structure|Arcuate nucleus (hypothalamus)}}

{{Infobox brain

| Name = Arcuate nucleus (medulla)

| Latin = nucleus arcuatus medullae oblongatae

| Image = Gray695.png

| Caption = Transverse section of medulla oblongata below the middle of the olive. ("Nucleus arcuatus" visible near bottom right.)

| Image2 = Gray683.png

| Caption2 = Dissection of brain-stem. Lateral view. (Labels for "External arcuate fibers" and "Dorsal external arcuate fibers" visible at lower right.)

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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.{{Cite book |last=Standring |first=Susan |url=https://www.worldcat.org/oclc/1201341621 |title=Gray's Anatomy: The Anatomical Basis of Clinical Practice |publisher=Elsevier |year=2020 |isbn=978-0-7020-7707-4 |edition=42th |location=New York |pages=445.e1 |oclc=1201341621}}

They receive afferents from the corticospinal tract.{{Citation needed|date=July 2024}}

They in turn project efferents into the cerebellum through the inferior cerebellar peduncle as:

• 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.