L3 PG Flashcards
role of PG
send out signals and hormones to another glands to release their hormones
how many parts does PG have
2- ANTEROIR AND POSTEROIR
how are hypothal and PG connected
by pituitary stalk
role of hypothal
homeostasis, controls ANS and endo functions
what nuclei of hypothal have to regulate hormone production
PVN and SO
what factors does hypithal respond to
environmental, neural and hormones
kinds of hypothal hormones
TRH, GnRK, GHRH, somatostatin, CRH, dopamine
role of hypothal hormones
influences PG to release their own hormones
- have no effect on physio process
structure of hypothal hormones
small peptides with short half life
what kind of release for hypothal hormones
pulsatile
how can hypothal hormones be used in clinical setting
to check pituitary function
how APG hormones synthesised
in APG
how APG regulated
by secreted hypothal factors or hormones through the blood into the APG
how PPG hormones syntheisised
in hypothalamus and transported via neuronal projections in the pituitary stalk into PPG
cell types of APG
corticotrophs, lactrotophs, thyrotrophs, gonadotrophs, somatotroph
what hormone associated with corticotrophs,
ACTH- regulation of adrenal cortex
what hormone associated with lactrotophs,
prolactin - milk production
what hormone associated with thyrotrophs
TSH for thryiod hormone production
what hormone associated with gonadotrophs,
LH/FSH - reproductive control
what hormone associated with somoatotrpohs
growth hormone - growth
PPG hormones
ADH, neurophysin, oxytocin
what do TSH, FSH, LH have in common
they are glycoproteins ( 2 chains), has 2 subunits
what do ACTH., GH and PRL have in common
they have single chain protein structure
pathway of hypothal-PG-thyroid
TRH( in hypothal)>TSH (APG)>thyroid>T4>T3
what molecules of thyroid hormone can do negative feedback
T3 and T4
what problem relating to thyroid if there’s a pituitary failure
secondary hypothyroidism (not enough)
what problem relating to thyroid if there’s a pituitary tumour
secondary hyperthyroidism (excess)
effects of LH and FSH
regulate testosterone syntheisis
- regulate menstrual cycle and fertility in ovary
what type of receptors do LH and FSH bind to
act on G proteins, results in cAMP and protein kinase A
what hormome is ACTH syntheisised from
POMO
pathway of hypo-PG-adrenal axis
CRH from hypo> ACTH from APG>adrenal cortex> cortisol
effects of ACTH
stimulates G protein receptor coupled to cAMP
- cholesteral converted to cortisol or sex hormones
what hypothal hormone have a neg influence on prolactin prolactin
dopamine, somatostatin
- the less influence they have on PRL, more PRL are made
what hypothal hormone have a pos influence on prolactin prolactin
TRH and VIP
effects of PRL
- regl of lymphocytes
- stimulate breats development
- maintain lactation
what are prolactinomas
tumour related with PRL
- interfere with HPG so results in infertility
treatment for prolactinomas
dopamine agonists to decrease PRL production
