Pituitary and Adrenal Glands Flashcards
what does ADH stand for and what does it do?
antidiuretic hormone
stimulates H2O retention, raises BP by contracting arterioles
why does oxytocin do?
stimulates contractions in labour
what is the difference between the anterior and posterior pituitary?
posterior had direct neurological release whereas the anterior is controlled by hormones therefore the reaction is much slower
where does GH have its affect and what is it via?
direct affect on all tissues
via insulin growth factor 1 produced by the liver
what stimulates and what inhibits GH release?
growth hormone releasing hormone stimulates
somatostatin inhibits
what kind of release does GH have over the day? when is most GH secreted?
pulsatile
during sleep
what are the functions of GH?
Skeletal growth and bone density
metabolism (works against insulin)
muscle strength
what is the difference in presentation of excessive GH in adults and children?
in adults it is more subtle as your bones cant grow anymore.
what stimulates TSH?
thyroxin releasing hormone (TRH)
what does TSH do?
activates follicular cells in thyroid to produce T3 + T4
what kind of feedback does TSH undergo?
negative
what does ACTH stand for and what is its release stimulated by?
adrenocorticotrophic hormone
stimulated by corticotrophin releasing hormone (CRH)
how are ACTH and CRH secreted?
in a pulsatile fashion
What else can cause ACTH release?
stress
When is activity of ACTH increased and decreased? When is it at its lowest?
Increased in am, decreased activity in pm, lowest at midnight
what stimulates FHS and LH production?
gonadotrophin releasing hormone
what happens when LH and FSH production is stimulated in men?
LH drives testosterone secretion.
FSH drives sperm production
what happens when LH and FSH production is stimulated in women?
follicular phase, LH pulses cause oestrogen release.
mid-late luteal phase LH pulses cause progesterone release
what type of feedback occurs on LH and FSH in women mid cycle surge of these hormones? what is it called?
+ve feedback, ovulation
what does prolactin do?
initiates and maintains lactation
what does prolactin act on?
peripheral tissues with no target gland
what is prolactin inhibited by?
dopamine
what affect does oestrogen have on prolactin?
increases secretion
what are the 5 p’s that cause high prolactin levels?
pregnancy
physiological (stress)
pharmacological (drugs that block dopamine, antipsychotics)
pituitary (prolactinomas, secreting excess prolactin)
polycystic ovaries
what do prolactinomas cause?
galactorrhoea, cause milk to be secreted outside of pregnancy
infertility in men/women