1 / 11

Hypophysis- Anterior Pituitary

Hypophysis- Anterior Pituitary. Prof. K. Sivapalan. Location. It is located in Sella Turcica , under Diaphragma Sella . It weighs 0.5g. In pregnancy it hypertrophies to 1g. 75% of the gland is anterior lobe- anterior pituitary. 25% is posterior pituitary. Development.

kirkan
Download Presentation

Hypophysis- Anterior Pituitary

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hypophysis-Anterior Pituitary Prof. K. Sivapalan

  2. Location. • It is located in SellaTurcica, under DiaphragmaSella. • It weighs 0.5g. • In pregnancy it hypertrophies to 1g. • 75% of the gland is anterior lobe- anterior pituitary. • 25% is posterior pituitary. Anterior Pituitary

  3. Development. • Rathke's pouch- anterior pituitary. • Floor of the third ventricle- posterior pituitary. Anterior Pituitary

  4. Anterior Pituitary.[Adenohypophysis] Anterior Pituitary

  5. Blood supply • Anterior lobe: superior hypophysial artery and Hypothalamic Hypophysial Portal system from hypothalamic nuclei. Anterior Pituitary

  6. ACTH • Single chain, 39 amino acids, parts resembling MSH and stimulates Melanocyte activity. • Half life- 3-4 minutes. • Regulation of secretion- studied under glucocorticoids. • ACTH and β-LPH- lipotropin are synthesized as one molecule and split before release. • Lipotropin resembles Endophins and Enkephalins which act like opiates. • ?use in stress. Anterior Pituitary

  7. Gonodotrophins- FSH + LH. FSH- follicular stimulating hormone. • Glycoprotein, 25000mw, a and b chains. • Action on testis and ovaries. • Secretion at puberty. LH- Luteinizing hormone. • Glycoprotein, 40000mw, a and b chains. • Action on testis and ovaries. • Secretion starts at puberty. Anterior Pituitary

  8. TSH • Glycoprotein, 30000mw, a and b chains. • Control- TRH • Action on thyroid gland. Anterior Pituitary

  9. Prolactin. • Structure- similar to GH. • Human Prolactin- 198 amino acids. • Control- Prolactin Inhibiting Hormone (Dopamine, - only inhibitory factor from hypothalamus) • Chlorpromazine stimulates secretion by reducing Dopamine receptors. • Regulation- • exercise and stress- surgical or psychological. • stimulation of nipple by nerves to hypothalamus. Anterior Pituitary

  10. Anterior Pituitary

  11. Actions of Prolactin • Secretion of milk in breast prepared by estrogen, progesterone, growth hormone and corticoids. • At high concentrations, similar metabolic actions as Growth Hormone. • (Ejection of milk -by oxytocin) • Hyperprolactinaemia: • Inhibition of menstruation in females • Impotence and hypogonadism in males. • Mechanism not known. ? Inhibition of gonadotropins by nervous stimuli from breast or prolactin Anterior Pituitary

More Related