WHAT IS HYPOTHALAMUS?• The portion of the brain that contains a number of small nuclei with a variety of functions.• The control center of all autonomic regulatory activities of the body.
LOCATION AND STRUCTURE• It is located in the middle of the base of the brain, and encapsulates the ventral portion of the third ventricle.• A small cone-shaped structure, it projects downward, ending in the pituitary stalk, a tubular connection to the pituitary gland.
FUNCTION• The most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland.• It synthesizes and secretes certain neurohormones, often called hypothalamic-releasing hormones, and these in turn stimulate or inhibit the secretion of pituitary hormones.
NEUROHORMONES• Hormone ~ Thyrotrophin-releasing hormone• Other names ~ Prolactin-releasing hormone• Symbol(s)~ TRH/TRF/ or PRH• stimulate thyroid-stimulating hormone (TSH) release from anterior pituitary hormone (primarily).• Stimulate prolactin (PRL) release from anterior pituitary.
NEUROHORMONES• Hormone~ Corticotrophin-releasing hormone• Symbols (s) ~ CRH/CRF• Stimulate adrenocorticotrophic hormones (ACTH) release from anterior pituitary.
NEUROHORMONES• Hormone~ Gonadotropin-releasing hormone• Symbols (s) ~ GnRH/ LHRH• Stimulating follicle-stimulating hormone (FSH) release from anterior pituitary.• Stimulate luteinizing hormone (LH) release from anterior pituitary.
NEUROHORMONES• Hormone~ Growth hormone-releasing hormone.• Symbol (s)~GHRH• Stimulate Growth hormone (GH) release from anterior pituitary.
NEUROHORMONES• Hormone~ Somatostatin• Other names~ growth hormone- inhibiting hormone• Symbols (s)~ SS/GHIH• Inhibit the Growth hormone (GH) release from anterior pituitary• Inhibit thyroid-stimulating hormone (TSH) release from anterior pituitary.
NEUROHORMONES• Hormone~ Dopamine• Other names~ Prolactin-inhibiting hormone• Symbols (s)~ DA/PIH• Inhibit prolactin release from anterior pituitary.• Responsible for sexual arousal
NEUROHORMONES• Hormone~ Oxytocin• For uterine contraction.• Lactation (letdown reflex or milk ejection reflex)
NEUROHORMONES• Hormone~ Vasopressin• Other names ~ antidiuretics hormone• Symbols (s)~ ADH/AVP• Increased water permeability in the distal convoluted tubule and collecting duct of nephrons, thus promoting water reabsorption and increasing blood volume