Arcuate nucleus (medulla)
Encyclopedia
In the medulla oblongata
Medulla oblongata
The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...

, the arcuate nucleus is a group of neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

s located on the anterior surface of the medullary pyramids. They receive fibers from the corticospinal tract
Corticospinal tract
The corticospinal or pyramidal tract is a collection of axons that travel between the cerebral cortex of the brain and the spinal cord....

 and send their axons through the anterior external arcuate fibers
Anterior external arcuate fibers
The anterior external arcuate fibers vary as to their prominence in different cases: in some they form an almost continuous layer covering the pyramid and olivary body, while in others they are barely visible on the surface.They arise from the cells of the gracile and cuneate nuclei, and passing...

 and striae medullares
Striae medullares
Winding around the inferior peduncle and crossing the area acustica and the medial eminence are a number of white strands, the striae medullares, which form a portion of the cochlear division of the vestibulocochlear nerve and disappear into the median sulcus....

 to the cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...

 via the inferior cerebellar peduncle
Inferior cerebellar peduncle
The upper part of the posterior district of the medulla oblongata is occupied by the inferior cerebellar peduncle , a thick rope-like strand situated between the lower part of the fourth ventricle and the roots of the glossopharyngeal and vagus nerves.Each cerebellar inferior peduncle connects the...

.

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

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