Hypothalamus

(redirected from Anterior hypothalamus)
Also found in: Dictionary, Thesaurus, Encyclopedia.

hy·po·thal·a·mus

(hī'pō-thal'ă-mŭs), [TA]
The ventral and medial regions of the diencephalon forming the walls of approximately the ventral half of the third ventricle; it is delineated from the thalamus by the hypothalamic sulcus, lying medial to the internal capsule and subthalamus, continuous with the precommissural septum anteriorly and with the mesencephalic tegmentum and central gray substance posteriorly. Its ventral surface is marked by (from rostral to caudal) the optic chiasma, the unpaired infundibulum that extends by way of the infundibular stalk into the posterior lobe of the hypophysis, and the paired mammillary bodies. The hypothalamus consists of the anterior hypothalamic area [TA], dorsal hypothalamic area [TA], intermediate hypothalamic area [TA], lateral hypothalamic area [TA], and posterior hypothalamic area [TA], each of these containing specific nuclei. It has afferent fiber connections with the mesencephalon, limbic system, cerebellum, and efferent fiber connections with the same structures and with the posterior lobe of the hypophysis; its functional connection with the anterior lobe of the hypophysis is established by the hypothalamohypophysial portal system. The hypothalamus is prominently involved in the functions of the autonomic (visceral motor) nervous system and, through its vascular link with the anterior lobe of the hypophysis, in endocrine mechanisms; it also appears to play a role in neural mechanisms underlying moods and motivational states.
See also: pituitary gland.
[hypo- + thalamus]

hypothalamus

(hī′pō-thăl′ə-məs)
n.
The part of the brain that lies below the thalamus, forming the major portion of the ventral region of the diencephalon and functioning to regulate bodily temperature, certain metabolic processes, and other autonomic activities.

hy′po·tha·lam′ic (-thə-lăm′ĭk) adj.

hy·po·thal·a·mus

(hī'pō-thal'ă-mŭs) [TA]
The ventral and medial region of the diencephalon forming the walls of the ventral half of the third ventricle; delineated from the thalamus by the hypothalamic sulcus, lying medial to the internal capsule and subthalamus, continuous with the precommissural septum anteriorly and with the mesencephalic tegmentum and central gray substance posteriorly. Its ventral surface is marked by, from before backward, the optic chiasma, the unpaired infundibulum, which extends by way of the infundibular stalk into the posterior lobe of the hypophysis, and the paired mammillary bodies. The nerve cells of the hypothalamus are grouped into the supraoptic paraventricular, lateral preoptic, lateral hypothalamic, tuberal, anterior hypothalamic, ventromedial, dorsomedial, arcuate, posterior hypothalamic, and premammillary nuclei and into the mammillary body. It has afferent fiber connections with the mesencephalon, limbic system, cerebellum, and efferent fiber connections with the same structures and with the posterior lobe of the hypophysis; its functional connection with the anterior lobe of the hypophysis is established by the hypothalamohypophysial portal system. The hypothalamus is prominently involved in the functions of the autonomic nervous system and, through its vascular link with the anterior lobe of the hypophysis, in endocrine mechanisms; it also appears to play a role in neural mechanisms underlying moods and motivational states.
See also: hypophysis

hypothalamus

The region of the under-surface of the brain immediately above the pituitary gland. The hypothalamus is the area in which the nervous and hormonal systems of the body interact. It receives information relating to hormone levels, physical and mental stress, the emotions and the need for physical activity, and responds by prompting the pituitary appropriately. Nuclei in the lower region of the hypothalamus contain neurons that secrete growth hormone releasing hormone, gonadotropin releasing hormone, somatostatin and other regulating substances.

hypothalamus

the part of the sides and floor of the brain derived from the forebrain. Associated with the control of body temperature, it also partially controls the PITUITARY GLAND and contains centres controlling sleep and wakefulness, feeding, drinking, speech and osmoregulation, the last by secretion of ADH from neurosecretory cells. It is also associated with aspects of reproductive behaviour.

Hypothalamus

A structure within the brain responsible for a large number of normal functions throughout the body, including regulating sleep, temperature, eating, and sexual development. The hypothalamus also regulates the functions of the pituitary gland by directing the pituitary to stop or start production of its hormones.

hypothalamus

A group of nuclei at the base of the brain located in the floor of the third ventricle. It consists of the optic chiasma, the paired mammillary bodies, the tuber cinereum, the infundibulum and the pars posterior of the pituitary gland.

hy·po·thal·a·mus

(hī'pō-thal'ă-mŭs) [TA]
Ventral and medial regions of diencephalon forming walls of approximately the ventral half of third ventricle; delineated from the thalamus by the hypothalamic sulcus, lying medial to the internal capsule and subthalamus, continuous with the precommissural septum anteriorly and with the mesencephalic tegmentum and central gray substance posteriorly.
[hypo- + thalamus]
References in periodicals archive ?
suprachiasmatic nucleus, or SCN, is an egg-shaped, densely packed collection of small cells of the anterior hypothalamus situated close to the midline.
Lesions of the anterior hypothalamus protected rats from the effects of experimental autoimmune encephalomyelitis (Abramsky, Wertman, Reches, Brenner, & Ovadia, 1987) and anterior lesions reduced the production of antibody to ovalbumin in rats (Tyrey & Nalbandov, 1972).
Heat and cold receptors convey information to the spinal cord, which passes it to the anterior hypothalamus in the brain.
Although scientists have yet to identify the precise function of the clump, called the interstitial nuclei of the anterior hypothalamus 3 (INAH 3), the hypothalamus is known as the seat of the emotions and sexual drives.
LeVay, who at the time was affiliated with the Salk Institute for Biological Studies, La Jolla, Calif., found that the size of the interstitial nuclei of the anterior hypothalamus differed between heterosexual and homosexual men, a discovery that he said "illustrates that sexual orientation in humans is amenable to study at the biological level" (Science 1991;253:1034-7).

Medical browser ?
Full browser ?