A complex brain structure composed of many nuclei with various functions. It is the head ganglion of the autonomic nervous system (ANS) and is involved in the control of heat regulation; heart rate, blood pressure, and respiration; sexual activity; water, fat, and carbohydrate metabolism; digestion, appetite, and body weight; wakefulness; fight-or-flight response; and rage.
The principal center in the fore-brain for integration of visceral functions involving the autonomic nervous system.
A part of the brain structure, lying near base of brain, it regulates a number of hormones. As a part of the brain, it constantly receives (neurochemical) signals from nerve cells (neurons). The hypothalamus
monitors those signals, and converts them into hormonal “signals” [e.g., it generates a “burst” of hormones in response to certain visual stimuli, certain physical (e.g., sexual) sfimuli, etc.].
Also, the hypothalamus is able to monitor and detect changes in the blood levels of hormones coming from endocrine glands. For example, the metabolic hormone insulin (from the pancreas) and the reproductive hormone estrogen (from the ovaries) both trigger changes in function in the hypothalamus. The hypothalamus regulates biological processes (e.g., metabolic rate, appetite, etc.). A major function of the hypothalamus is to control reproduction, via secretion of gonadotropin-releasing hormone (GnRH) from the tips of hypothalamic nerve fibers that extend downward toward (into) the pituitary gland. Similarly, the hypothalamus also helps to control the body’s growth (from birth until the end of puberty) via secretion of growth hormone-releasing factor (GHRF) to the pituitary gland.
A part of the diencephalon of the brain, it is a major actor in the limbic system. This is a functional, not anatomic, system in the brain that influences and is influenced by emotions. Call the limbic system an ad hoc committee that decides how things are going today, based on past, present, potential, and myriad informational inputs from the meat. The hypothalamus gathers the data and sets the levels of the pituitary thermostat. The pituitary does what the hypothalamus tells it to do, and our whole chemical nervous system responds to the pituitary, which responds to the hypothalamus, which, along with the rest of the limbic system, decides the kind of day we need to get ready for. And to think that some doctors used to (and still) scoff at a “psychosomatic disorder”
A portion of the diencephalon of the brain.
A portion of the brain lying beneath the thalamus at the base of the cerebrum and forming the floor and part of the walls of the third ventricle.
Part of the brain forming floor and wall of third ventricle.
The part of the brain above the pituitary gland, which controls the production of hormones by the pituitary gland and regulates important bodily functions such as hunger, thirst and sleep.
A part of the central nervous system that consists of a group of nuclei at the base of the brain in relation to the floor and walls of the third ventricle.
Part of the brain that controls the endocrine system, the autonomic nervous system, and many other body functions (e.g., body temperature, thirst, hunger).
Brain structure located inferior to the thalamus that regulates temperature, appetite, thirst, sleep, behavioral patterns, and secretions from the pituitary gland.
A structure located near the center of the base of the brain. The hypothalamus directs the workings of the autonomic nervous system, which regulates vital, involuntary functions such as blood pressure, sleep, body temperature, appetite, and thirst. The hypothalamus also directs the hormonal activities of the endocrine system (hormonal system) by stimulating and inhibiting production of hormones by the pituitary gland. The hypothalamus also controls the sympathetic nervous system, which prepares the body for a response to stress—the so-called fight-or-flight mechanism.
The region of the forebrain in the floor of the third ventricle, linked with the thalamus above and the pituitary gland below. It contains several important centers controlling body temperature, thirst, hunger, and eating, water balance, and sexual function. It is also closely connected with emotional activity and sleep and functions as a center for the integration of hormonal and autonomic nervous activity through its control of pituitary secretions.
That part of the fore-brain situated beneath, and linked with, the thalamus on each side and forming the floor of the third ventricle. Also linked to the pituitary gland beneath it, the hypothalamus contains collections of nerve cells believed to form the controlling centres of (1) the sympathetic and (2) the parasympathetic nervous systems. The hypothalamus is the nervous centre for primitive physical and emotional behaviour. It contains nerve centres for the regulation of certain vital processes the metabolism of fat, carbohydrate and water; sleep; body temperature; and sexual function.
The bottom (ventral) half of the diencephalon of the brain. It is the regulator of the essential homeostatic balance of body fluids, salt concentrations, temperature, and energy metabolism as well as the governor of reproductive cycles and certain emotional responses. The hypothalamus is a single structure, but it comprises two mirror-image walls of neural tissue on the left and the right sides of the ventral half of the third ventricle. In the embryo, these walls are at the front end of the neural tube; in the adult, the hypothalamus begins at the lamina terminalis (at the base of the frontal lobes) and just below the lamina terminalis; the optic chiasm lies in front of the hypothalamus. The base of the hypothalamus ends in a stalk (the infundibulum) from which hangs the pituitary gland (the hypohysis); farther caudally, two mammillary bodies bulge from the bottom of the hypothalamus. At the top of the hypothalamus, the lateral ventricles empty into the third ventricle via a left and a right interventricular foramen, and behind (caudal to) the foramina are the right and left thalami. The hypothalamus is the central controller of the preganglionic sympathetic and parasympathetic nervous systems; it is also the central regulator of the pituitary gland. The hypothalamus is a collecting zone for input from the cerebral cortex, the hippocampus, the amygdala, the retina, and the brainstem; it sends output to the cerebral cortex, the thalamus, the brainstem, and the pituitary gland. Besides the pituitary gland and the mammillary bodies, the hypothalamus contains many discrete CNS nuclei in its walls, and these nuclei are categorized according to their regional locations. The anterior region (which is subdivided into the preoptic and supraoptic areas) contains nuclei involved in the regulation of gonadal hormones, body fluid levels, body temperature, and circadian rhythm; the middle (infundibular or tuberal) region contains nuclei involved in regulating levels of adrenocortical, thyroid, growth, and gonadal hormones; and the posterior (mammillary) region is a central part of the midbrain-mammillary-thalamic-midbrain circuit of the limbic system.
A part of the brain that regulates body temperature, sleep, water balance, and blood pressure, as well as regulating the hormones of the endocrine system.
Region of the diencephalon that exerts control over fight-or-flight activities, fear and anger states, and a host of other functions.
Deep within the cerebral cortex lies a region of neural clusters that play a crucial role in the regulation of an individual’s appetite and hunger.
An anatomical component situated in the brain that assumes responsibility for a wide array of essential functions across the body, encompassing the regulation of sleep, body temperature, appetite, and sexual development. Moreover, the hypothalamus exercises control over the activities of the pituitary gland, directing it to initiate or cease the production of its hormones.
The hypothalamus is a small area in the brain, approximately the size of a cherry, located behind the eyes and beneath another brain region known as the thalamus. This part of the brain boasts neural connections to most other areas within the nervous system.
The hypothalamus governs the sympathetic nervous system, which is a component of the autonomic nervous system. When there’s a sudden surge of alarm or excitement, signals from higher brain regions are sent to the hypothalamus, activating the sympathetic nervous system. This activation results in a rapid heartbeat, dilation of pupils, increased breathing rate, and enhanced blood flow to the muscles, collectively known as the “fight or flight” response.
The hypothalamus also contains clusters of nerve cells that are involved in maintaining body temperature. If the blood reaching the brain is either too hot or too cold, the hypothalamus activates mechanisms such as sweating or shivering to regulate the body’s temperature. Additionally, it gathers information from internal sensors about the body’s water levels and the concentration of glucose in the blood; if these values are low, the hypothalamus triggers thirst and hunger. Beyond these functions, the hypothalamus plays a key role in managing sleep patterns, stimulating sexual behavior, and influencing mood and emotions.
Another significant function of the hypothalamus is to synchronize the operations of the nervous and endocrine (hormonal) systems.
The hypothalamus is linked to the pituitary gland through a small stem of nerve fibers and oversees the gland’s hormonal secretions. One way it achieves this control is through direct nerve connections. Another way involves specialized nerve cells that produce hormones known as releasing factors. These factors move into specific blood vessels and travel to the pituitary gland. Consequently, the hypothalamus translates nerve signals into hormonal signals, enabling it to indirectly regulate numerous endocrine glands, such as the thyroid gland, the adrenal cortex, and the ovaries or testes.
Issues with the hypothalamus typically stem from conditions like an intracerebral hemorrhage or tumors in the hypothalamus or pituitary gland. The resulting effects can be quite varied, from hormonal imbalances to irregularities in temperature regulation, as well as changes in appetite and sleep requirements.
A section of the lower cerebrum located below the thalamus. It impacts the posterior part of the pituitary gland and houses vital centers responsible for regulating temperature, maintaining water balance, and managing sleep.