1. hypothal and pituitary Flashcards
what hormones are released by the ant pituitary
FSH LH ACTH TSH PL GH
what hormone controls FEMALE hormone production, and how
GnRH
causes ant pituitary to secrete FSH and LH
what is the role of inhibin in female hormone production
feed back to inhibit FSH secretion
what hormone controls MALE hormone production, and how
GnRH
stimulate ant pituitary to produce FSH and LH
what does FSH and LH do in female hormone production
causes maturation of immature follicles to corpus luteum
what does FSH and LH do in male hormone production
FSH: act on Sertoli cells in the testes -> facilitate spermatogenesis
LH: acton leydig cells, which then also stimulate Sertoli cells
what does testosterone and inhibin do in male hormone production
inhibit GnRH, LH and FSH secretion
what are 2 examples of a protein inhibitory factor and releasing factor?
PIF: dopamine (D2 receptor)
PRF: thyrotropin releasing hormone TRH
during suckling, what are the immediate reactions in the hypothalamus after the nipple mechanoreceptors are activated?
- inhibition of dopamine receptors (inc milk synthesis)
- stimulation of neurones to secrete oxytocin from post. pituitary (stimulations milk ejection)
when suckling, describe what the activation of nipple mechanoreceptors inhibits (starting in the hypothalamus)
- inhibit dopamine receptors
- which inhibit lactotroph action on anterior pituitary
- increase in milk gland cells and milk synthesis
what is galactorrhoea
milk secretion from breast
what is gynaecomastia
excess breast growth in females and males
what could prolactinaema lead to
galactorrhea
gynaecomastia
infertility (males and females)
(suppresses menstrual cycle
where is milk production stimulated
prolactin produced by lactotrophs in anterior pituitary
what does dopamine release affect
inhibits PL release via D2 receptors
how can hyperprolactinaemia be treated
D2 agonists: bromocriptine, cabergoline
what is GH secretion controlled by?
hypothalamic hormones:
GHRH
somatostatin
GH and IGF negative feedback
what are the main actions of GH
long bone growth until fusion of epiphysis
anti-insulin
metabolic effects related to growth
what is the result of hyper secretion of GH
before fusion of epiphysis = GIGANTISM (childhood)
after fusion = ACROMEGALY (adulthood)
what are the main treatment options for acromegaly
trans-sphenoidal surgery
D2 agonists: bromocriptine, cabergoline
somatostatin agonists
what are some somatostatin agonists used to treat acromegaly
octreotide - long acting somatostatin
lanreotide - analogues SST2
pasireotide SST5
what is the role of SST2 and SST5
SST2 and SST5 inhibit GH release
SST5 inhibits ACTH and insulin release
what is the results hypo secretion of GH
before fusion of epiphysis = short stature
after = adult GH deficiency
how can one treat short stature
- recombinant hGH (somatotropin)
- recombinant hIGF-1 (mecasermin)
