The tuber cinereum is the portion of

hypothalamus The hypothalamus (: hypothalami; ) is a small part of the vertebrate brain that contains a number of nucleus (neuroanatomy), nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrin ...

forming the floor of the

third ventricle The third ventricle is one of the four connected cerebral ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and lef ...

situated between the

optic chiasm In neuroanatomy, the optic chiasm, or optic chiasma (; , ), is the part of the brain where the optic nerves cross. It is located at the bottom of the brain immediately inferior to the hypothalamus. The optic chiasm is found in all vertebrates, ...

, and the

mammillary bodies The mammillary bodies also mamillary bodies, are a pair of small round brainstem nuclei. They are located on the undersurface of the brain that, as part of the diencephalon, form part of the limbic system. They are located at the ends of the ant ...

. The tuberal region is one of the three regions of the hypothalamus, the other two being the chiasmatic region and the mamillary region.

Structure

The tuber cinereum is a convex mass of grey matter, a ventral/inferior distention of the hypothalamus forming the floor of the

. The portion of the tuber cinereum at the base of the infundibulum (pituitary stalk) is the

median eminence The median eminence is generally defined as the portion of the ventral hypothalamus from which the portal vessels arise. The median eminence is a small swelling on the tuber cinereum, posterior to and on top of the pituitary stalk; it lies in th ...

; the infundibulum extends ventrally/inferiorly from the

to become continuous with the infundibulum. The

arcuate nucleus The arcuate nucleus of the hypothalamus (ARH), or ARC, is also known as the infundibular nucleus to distinguish it from the arcuate nucleus of the medulla oblongata in the brainstem. The arcuate nucleus is an aggregation of neurons in the medio ...

is a part of the tuber cinereum. The lateral portions of tuber cinereum lodge the lateral tuberal nucleus, and

tuberomammillary nucleus The tuberomammillary nucleus (TMN) is a histaminergic nucleus located within the posterior third of the hypothalamus. It is part of the tuber cinereum. It largely consists of histaminergic neurons (i.e. histamine-releasing neurons). It is invo ...

. The basolateral aspect of the tuber cinereum often presents slight elevations produced by the underlying lateral tuberal nucleus - the lateral eminence.

Relations

The tuber cinereum is situated caudal to the

, medial to the

optic tract In neuroanatomy, the optic tract () is a part of the visual system in the brain. It is a continuation of the optic nerve that relays information from the optic chiasm to the ipsilateral lateral geniculate nucleus (LGN), pretectal nuclei, and su ...

(which flanks it on either side), and rostral to the two

. is continuous anteriorly with the

lamina terminalis The lamina terminalis is a thin layer that forms the median portion of the wall of the forebrain. It stretches from the interventricular foramen (foramen of Monro) to the recess at the base of the optic stalk (optic nerve) and contains the vas ...

, and laterally with the

anterior perforated substance The anterior perforated substance is a part of the brain. It is bilateral. It is irregular and quadrilateral. It lies in front of the optic tract and behind the olfactory trigone. Structure The anterior perforated substance is bilateral. It ...

Blood supply

Arterial blood supply to the tuber cinereum is provided by the

anterior choroidal artery The anterior choroidal artery is a bilaterally paired artery of the brain. It is typically a branch of the internal carotid artery which supplies the choroid plexus of lateral ventricle and third ventricle as well as numerous structures of the br ...

Microanatomy

Capillaries A capillary is a small blood vessel, from 5 to 10 micrometres in diameter, and is part of the microcirculation system. Capillaries are microvessels and the smallest blood vessels in the body. They are composed of only the tunica intima (the in ...

of the tuber cinereum are specialized and

confluent Confluent, Inc. is an American technology company headquartered in Mountain View, California. Confluent was founded by Jay Kreps, Jun Rao and Neha Narkhede on September 23, 2014, in order to commercialize an open-source streaming platform Apa ...

to enable rapid communication via brain- or blood-borne factors between compartments of the tuber, a capillary system described as the

hypophyseal portal system The hypophyseal portal system is a system of blood vessels in the microcirculation at the base of the brain, connecting the hypothalamus with the anterior pituitary. Its main function is to quickly transport and exchange hormones between the hyp ...

. The subregion of the hypothalamic

closest to the median eminence contains specialized

permeable Permeability, permeable, and semipermeable may refer to: Chemistry *Drug permeability *Semipermeable membrane, a membrane which will allow certain molecules or ions to pass through it by diffusion *Vascular permeability, the movement of fluids a ...

capillaries surrounded by wide pericapillary spaces, enabling moment-to-moment sensing of circulating blood.

Additional images

File:Gray715.png, Mesal aspect of a brain sectioned in the median sagittal plane. File:Gray748.png, The fornix and corpus callosum from below.

References

External links

* - "

Interpeduncular fossa The interpeduncular fossa is a deep depression of the ventral surface of the midbrain between the two cerebral crus, cerebal crura. It has been found in humans and macaques, but not in rats or mice, showing that this is a relatively new evolutiona ...

" (#4) {{Authority control Hypothalamus