hypothalamischpituitäre

Hypothalamic refers to the region and functions of the hypothalamus, a brain structure that forms the ventral part of the diencephalon, located just below the thalamus. The hypothalamus serves as a central regulator of autonomic and endocrine processes, linking the nervous system to the endocrine system via the pituitary gland.

An important mechanism is the hypothalamic-pituitary axis. The hypothalamus secretes releasing and inhibiting hormones into the portal circulation to control the anterior pituitary, which in turn releases hormones such as TSH, ACTH, luteinizing hormone, follicle-stimulating hormone, growth hormone, and prolactin. The hypothalamus also produces neurohormones such as vasopressin and oxytocin, which are stored and released from the posterior pituitary.

Specific hypothalamic nuclei regulate diverse functions. The arcuate nucleus influences hunger and energy balance; the ventromedial and lateral regions participate in feeding behavior; the supraoptic and paraventricular nuclei regulate water balance and stress responses. The hypothalamus integrates inputs from the limbic system and retina and coordinates temperature, sleep-wake cycles, and circadian rhythms.

Clinical relevance: dysfunction can affect metabolism, growth, reproduction, stress responses, and fluid balance. Conditions include central diabetes insipidus, hypopituitarism, obesity due to impaired energy homeostasis, and hypothalamic syndrome from tumors, inflammation, or trauma. Understanding hypothalamic circuits aids in diagnosing and treating endocrine and autonomic disorders.