Find the word definition

Wikipedia
Arcuate nucleus

The arcuate nucleus (or infundibular nucleus) is an aggregation of neurons in the mediobasal hypothalamus, adjacent to the third ventricle and the median eminence. The arcuate nucleus includes several important populations of neurons, including: neuroendocrine neurons, centrally projecting neurons, and others.

Arcuate nucleus (medulla)

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. They receive fibers from the corticospinal tract and send their axons through the anterior external arcuate fibers and striae medullares to the cerebellum via the inferior cerebellar peduncle.

Arcuate nuclei are capable of chemosensitivity and have a proven role in controlling respiratory frequency.