1. Structure and function of hypophysis.

Which hormone pass through the neurohypophysis?

1. ADH =antidiuretic hormones (also called vasopressin ) 2.Oxycitin

What is the function of ADH?

Antidiuretic hormone is an hormone that acts on tubules of kidneys and nephrons (distal tubules and collecting duct), facilitated reabsorption of water by insertion of aquaporins (water channels) into the membrane of the kidneys tubules and change the permeability. The result is retention of water and reduce lose of water through urine . This is cause elevation in blood pressure.

The hypophysis divided to:

1. anterior adenohypophysis 2. posterior neurohypophysis

What is ACTH? What is the function of ACTH?

ACTH= adrenocorticotropin hormone that controls function of zona fasciculata (glucocorticoids) and zona reticularis (adrogens) in adrenal glands.

The function of the the hypophysis

- The hypothalamus controls the activity of the pituitary gland. - The hypophysis and hypothalamus form the hypothalamohypophysial system/axis, which is responsible for the majority of hormonal regulation and is also closely related to the autonomic nervous system.

pars intermedia (Intermediate part) ( of the adenohypophysis) Tell about it

1. Rudimentary region. 2.It is lined by simple cuboidal epithelium that forms a barrier between the adeno and neurohypophysis. 3.The cells are mostly basophils, chromophobes and colloid filled cysts (contain follicle (with colloid - remnant of Rathke' pouch) lined by cuboidal epithelium) in the lumen between the glands.

a. Pars distalis ( of the adenohypophysis) Tell about it:

1. comprise the bulk of the anterior lobe of the pituitary gland 2.It is made by cords of aggregated cells and sinusoidal capillaries. 3. The cells granules release secretion by exocytosis to the open blood system of the adenohypophysis (connected with superior hypophyseal artery). 4. Cells are characterized as chromophobes or chromophils, in which case may be acidic or basophilic cells. (The cells divided according to there affinity for histological dyes)

What is the functions of oxytocin?

1..stimulates contraction of uterine smooth muscle. 2.It also stimulates alveoli and lactiferous ducts in mammary glands to eject milk.

pars nervosa ( nervous part) of the neurohypophysis Tell about it

1.Bigger part 2.containing white matter axons ( unmyelinated axons) and no secretory cells. 3. Axons transport oxytocin and vasopressin into capillaries. 4. Herring bodies are accumulations of secretory granules in axons. 5.pituicytes are supporting cells (glial cells) that may contain lipofuschin granules

Infundibulum of the neurohypophysis Tell about it

1.Smaller part 2. Is the stalk attached to the hypothalamus at the median eminence ( at the base of the hypothalamus)

The secretions from the hypophysis:

1.Somatotropin 2.Prolactin 3.TSH 4.FSH 5.LH 6.ACTH

What is Somatotropin? What is function of Somatotropin?

Somatotropin= growth hormone. It acts on liver and kidney which produce and secrete hormones ( insulinlike growth factor 1 (IGF-1), (which is turn stimulates division of progenitors cells located in growth plates) that cause elongation of epiphyseal plates in long bones resulting in body growth.

Neurohypophysis

a. Nervous part ( pars nervosa) a. Infundibulum

Adenohypophysis- divided to:

a. Pars distalis b. Tuberal part (pars tuburalis) c.Intermediate part (pars intermedia)

What is the origin of the adenohypophysis ?

originated in ectoderm in the roof of stomodeum (mouth). It forms Rathke's pouch then migrats upwards.

What is the origin of the Neurohypophysis?

origined from neuroectoderm of the brain as a growth downwards from the diencephalon (hypothalamus).

Which type Hypophysis called also ?

pituitary gland

posterior neurohypophysis held by?

posterior neurohypophysis held from the hypothalamus by a stalk or infundibulum.

Which cells produce proclactin? What is function of proclactin?

proclactin produced by mammotrophs initiates milk formation, and secretion of lipids to milk.

What is the pass way of the hormones that reach to the neurohypophysis?

these hormones pass from the hypothalamus through the-->infundibulum to àneurohypophysis where they are accumulated and released.

That covers the hypothalmus?

Cover by a CT capsule which sends out trabecula with vessels and nerves.

What is FSH? What is function of FSH? ( male and female)

FSH is follicle stimulating hormone In female, FSH stimulate follicular development in the ovary ( FSH stimulate growth an maturation of the ovarian follicle) In male, FSH stimulates spermatogenesis in the testis ( FSH enhance the secretion of androgen binding hormone from Sertoli cells)

Pars tuburalis (Tuberal part) ( of the adenohypophysis) Tell about it:

It's funnel shaped region surrounding the infundibulum.

What is LH? What is the function of LH?( male and female)

LH is leuteinizing hormone In female, LH regulate the maturation of ovarian follicle, ovulation and formation of corpus luteum. In male, LH act on the Leydig cells (produce testosterone) of the testis (stimulates spermatogenesis in the testis).

Where the pituitary gland located?

The pituitary gland is a small gland located in the hypophyseal fossa of the sphenoid bone (sella turcica). Surface is in contact with the sella turcica and covered by a dural fold called diaphragma sella.

How the pituitary gland is connected to the hypothamnus?

The pituitary stalk connects the pituitary gland to the hypothalamus.

Where the adenohypophysis and the neurohypophysis meed? And What they are leave?

The two meet together at the intermediate part and leave a small pouch as a remnant.

Which type the hypophysis gland is ?

Trabecular type of endocrine gland