`star` The Hypothalamus
`star` The Pituitary Glands


`color{green}(★)` The `color{violet}("hypothalamus")` is the basal part of `color{violet}("diencephalon, forebrain")` and it regulates a wide spectrum of body functions.

`color{green}(★)` It contains several groups of `color{violet}("neurosecretory cells")` called `color{violet}("nuclei")` which produce `color{violet}("hormones.")`

`color{green}(★)` These `color{violet}("hormones")` regulate the `color{violet}("synthesis")` and secretion of `color{violet}("pituitary hormones.")`

`color{green}(★)` However, the `color{violet}("hormones")` produced by `color{violet}("hypothalamus")` are of two types, the releasing `color{violet}("hormones")` (which stimulate secretion of `color{violet}("pituitary hormones")` ) and the inhibiting hormones (which inhibit secretions of `color{violet}("pituitary hormones")` ).

`color{green}(★)` For example a `color{violet}("hypothalamic hormone")` called `color{violet}("Gonadotrophin")` releasing `color{violet}("hormone")` (GnRH) stimulates the `color{violet}("pituitary synthesis")` and release of `color{violet}("gonadotrophins.")`

`color{green}(★)` On the other hand, somatostatin from the `color{violet}("hypothalamus")` inhibits the release of growth `color{violet}("hormone")` from the `color{violet}("pituitary.")`

`color{green}(★)` These `color{violet}("hormones")` originating in the `color{violet}("hypothlamic neurons")`, pass through axons and are released from their `color{violet}("nerve endings.")`

`color{green}(★)` These `color{violet}("hormones")` reach the `color{violet}("pituitary gland")` through a portal `color{violet}("circulatory system")` and regulate the functions of the `color{violet}("anterior pituitary.")`

`color{green}(★)` The `color{violet}("posterior pituitary")` is under the direct `color{violet}("neural regulation")` of the `color{violet}("hypothalamus.")`


`color{green}(★)` The `color{violet}("pituitary gland")` is located in a `color{violet}("bony cavity")` called `color{violet}("sella tursica")` and is attached to `color{violet}("hypothalamus")` by a stalk.

`color{green}(★)` It is divided anatomically into an `color{brown}("adenohypophysis")` and a `color{brown}("neurohypophysis.")`

`color{green}(★)` `color{violet}("Adenohypophysis")` consists of two portions, pars distalis and pars intermedia.

`color{green}(★)`The pars distalis `color{violet}("region of pituitary")`, commonly called `color{violet}("anterior pituitary")`, produces `color{brown}("growth hormone")` (GH), `color{brown}("prolactin")` (PRL), `color{brown}("thyroid stimulating hormone")` (TSH), `color{brown}("adrenocorticotrophic hormone")` (ACTH), `color{brown}("luteinizing hormone")` (LH) and `color{brown}("follicle stimulating hormone")` (FSH).

`color{green}(★)` Pars intermedia secretes only one `color{violet}("hormone")` called `color{brown}("melanocyte stimulating hormone")` (MSH).

`color{green}(★)` However, in humans, the pars intermedia is almost merged with `color{violet}("pars distalis.")`

`color{green}(★)` `color{violet}("Neurohypophysis")` (pars nervosa) also known as `color{violet}("posterior pituitary")`, stores and releases two hormones called `color{brown}("oxytocin")` and `color{brown}("vasopressin")`, which are actually `color{violet}("synthesised")` by the `color{violet}("hypothalamus")` and are transported axonally to `color{violet}("neurohypophysis.")`

`color{green}(★)` Over-secretion of GH stimulates abnormal growth of the body leading to `color{violet}("gigantism")` and low secretion of GH results in stunted growth resulting in `color{violet}("pituitary dwarfism.")`

`color{green}(★)` Prolactin regulates the growth of the `color{violet}("mammary glands")` and formation of milk in them.

`color{green}(★)` `color{violet}("TSH")` stimulates the `color{violet}("synthesis")` and secretion of `color{violet}("thyroid hormones")` from the `color{violet}("thyroid gland. ")`

`color{green}(★)` ACTH stimulates the synthesis and secretion of steroid hormones called `color{brown}("glucocorticoids")` from the adrenal cortex.

`color{green}(★)` LH and FSH stimulate gonadal activity and hence are called `color{brown}("gonadotrophins.")`

`color{green}(★)` In males, LH stimulates the synthesis and secretion of `color{violet}("hormones")` called `color{brown}("androgens ")`from testis.

`color{green}(★)` In males, FSH and androgens regulate `color{violet}("spermatogenesis.")`

`color{green}(★)` In females, LH induces ovulation of fully `color{violet}("mature follicles")` (graafian follicles) and maintains the corpus
luteum, formed from the remnants of the `color{violet}("graafian follicles")` after ovulation.

`color{green}(★)` FSH stimulates growth and development of the `color{violet}("ovarian follicles")` in females.

`color{green}(★)` MSH acts on the `color{violet}("melanocytes")` (melanin containing cells) and regulates pigmentation of the skin.

`color{green}(★)` `color{violet}("Oxytocin")` acts on the `color{violet}("smooth muscles")` of our body and stimulates their contraction.

`color{green}(★)` In females, it stimulates a `color{violet}("vigorous contraction of uterus")` at the time of child birth, and milk ejection from the
`color{violet}("mammary gland. ")`

`color{green}(★)` Vasopressin acts mainly at the `color{violet}("kidney")` and stimulates resorption of water and `color{violet}("electrolytes")` by the distal `color{violet}("tubules")` and thereby reduces loss of water through `color{violet}("urine")` (diuresis).

`color{green}(★)` Hence, it is also called as `color{brown}("anti-diuretic hormone")` (ADH).