endocrinology Flashcards
what is the role of the posterior pituitary gland?
storing hormones
what is the role of the anterior pituitary gland?
producing hormones
what glands are controlled by the pituitary gland?
parathyroid thyroid adrenal cortex pancreas ovaries/testes
what glands are not controlled by the pituitary gland?
parathyroid (calcium storage)
adrenal medulla - adrenaline and noradrenaline
pancreas (sugar)
gut hormones
what is CRH and what does it do?
corticotrophin released hormone, it stimulates ACTH secretion which in turn stimulates the adrenal gland
what is GHRH and what does it do?
growth hormone releasing hormone and it stimulates CH
what is TRH and what does it do?
thyrotrophin releasing hormones which stimulates TSH secretion
what 5 hormones does the anterior pituitary gland produce?
GH ACTH LH and FSH TSH PRL
what is GH? and what does it do?
growth hormone
stimulates skeletal growth
what is ACTH?
adrenocorticotrophic hormone
stimulates the adrenal gland to produce steroids
What are LH and FSH?
gonadotrophin hormones
stimulates the testes and ovaries to produce sex hormones
what is TSH?
thyroid stimulating hormone
stimulates the thyroid to produce thyroid hormones
what is PRL?
prolactin
stimulates breast milk production
what do adrenal steroids inhibit?
ACTH and CRH
what does thryroid hormones inhibit?
TRH and TSH
what do sex hormones inhibit?
GnRH, LH and FSH
what does Gh inhibit?
GHRH
what do C-cells do and where are they?
in thyroid gland, they produce calcitonin for calcium metabolism
not under control of pituitary but by the 4 parathyroid glands sitting behind the thyroid
what is calcium metabolism controlled by?
parathyroid glands
what 4 things take part in calcium metabolism?
kidneys
gut
bones
thyroid
how do the kidneys help with calcium metabolism?
they excrete calcium and produce active vitamin D which increases the absorption of calcium
how does the gut help with calcium metabolism?
involved in the absorpiton of calcium
how does the thyroid help with calcium metabolism?
c-cells in the thyroid produce calcitonin for calcium metabolism.
not under the control of the pituitary
how do bones help with calcium metabolism?
storage of caclium
what does the adrenal cortex produce?
corticosteroids - cortisol
androgens - male sex hormones
mineralcorticord - aldosterone
what does the adrenal medulla produce?
catecholamines - adrenaline, noradrenaline and dopamine
what part of the adrenal gland is not controlled by the pituitary?
the adrenal medulla
or production of mineralcorticord by the cortex. this is renin-angiotensin system which controls blood pressure
in primary hyperthyroidism what levels of thyroid hormone and TSH would you expect to see?
high levels of thyroid hormone but low levels of TSH as it is a problem in the thyroid not the pituitary
what can you use static tests for?
diagnose problems in thyroid and sex glands
what can you use stimulation tests for?
hormonal undersecretion where static tests are not enough as results are ambiguous
what can you use surpression tests for?
hormonal oversecretion
what is the synacthin test?
giving patient CTH to test for adrenal insufficiency
failure to respond to CTH suggests failure of the gland
give 2 examples of surpression tests?
giving steroids to test for endogenous steroid production
giving glucose to test for GH secretion - as glucose should switch off GH secretion
what is a prolactinoma?
a pituitary tumour secreting prolactin
what are the symptoms of prolactin over-secretion?
galactorrhoea
amenorrheoa in women
sexual dysfunction in men
headaches and visual feild problems
which kind of over-secreting pituitary tumour can be treated non-surgically?
prolactinoma
what are the symptoms of excess growth hormone in adults?
acrmegalic face
wide and large hands/feet
increased sweating
what is the diagnosis of growth hormone excess?
surpression tests are neccessary
glucose is given, this should decrease palsma levels of GH but not in those with GH excess
imaging is neccessary to confirm presence of pituitary gland tumour
what is the treatment of oversecreting GH tumour?
surgical removal of the tumour
radiotherapy and medical therapy sometimes needed as surgery does not always remove whole tumour
what are 3 cuases of cortisol oversecretion?
pituitary secreting ACTH tumour - cushing disease
adrenal tumour screting cortisol
cancer producing ACTH - lung cancer?
symptoms of cortisol over secretion
growth arrest in children typical face: round face, acne, hirsuitism fat redistribution = truncal obesity skin abnormalities = thin skin, brusing, stretch marks hypertension diabetes increased risk of infection worsening wound healing
how do you test for over secretion of cortisol?
surpression tests - dexamethanosome surpession test
this tests for failure to surpress endogenous cortisol production
how do you treat cortisol over secretion?
for pituitary or adrenal:
surgery and radiotherpay/medical treatment
cancer related:
treat original cancer first
what is the most common cause of hyperthyroidism?
graves disease
an autoimmune condition that results in the body attacking the thyroid gland, causing it to over secrete
what are 5 causes of hyperthyroidism?
graves disease toxic nodule/toxic MNG thyroiditis drug induced - e.g. aminodorane rarities
name 5 clinical presentations of hyperthyroidism
hyperactivity/irritability/insomnia palpitations weightloss menstrual probs thyroid eye disease
what can be seen in examination of someone with hyoerthyroidism?
hand tremor
increased sweating
fast pulse
enlarged thyroid
what does a smooth enlarged thyroid suggest?
graves disease
what does a nodular enlarged thyroid suggest?
toxic nodules
what does a tender enlarged thyroid suggest?
thyroiditis
how can you test for hyperthyroidism?
blood test
what are 3 ways to treat hyperthyroidism?
antithyroid drugs
radioactive iodine
surgery
symptoms of GH undersecretion in children and adults
children = failure to grow
adults = not always any symptoms, but can show as tiredness and depression
test for GH under secretion?
stimulation test:
glucagon stimulation test
insulin stress test
treatment for GH under secretion?
growth hormone replacement
what can cause steroid undersecretion?
adrenal or pituitary failure
what are 4 clinical presentation sof steroid under secretion
failure of growth in children
severe tiredness
dizziness - low BP
abdominal pain - V+D
How do you treat steroid undersecretion?
replace missing hormones with tablets
how do you test for steroid undersecretion?
stimulation testing
synacthen test (ACTH) if primary adrenal failure is suspected
GST or IST if secondary adrenal failure is suspected
what are the cuases of hypothyroidism - primary and secodnary?
primary = autoimmune or drug induced
secondary = complete pituitary failure
what are some symptoms of hypothyroidism?
weakness and dry skin cold and less sweating imparied memory constipation weight gain hair loss
how do you test for hypothyroidism?
static thyroid function test
how do you treat hypothyroidism?
thyroid hormone replacement
what are the causes of primary sex hormone undersecretion and secondary?
primary = ovarian failure or testicular failure secondary = pituitary failure
what is the presentation of sex hormone under secretion in men and women?
men = erectile dysfunction and decreased libido women = menstrual abnormalities
how do you test for sex hormone under secretioN?
Static test
testosterone in men
oestradiol in women
FSH/LH in both
how do you treat sex hormone under secretioN?
hormone replacement therpay
pituitary hormone replacement
what are 2 causes of pituitary failure?
large tumour
infarction
how do you test for pituitary failure?
combination of static and stimulatroy tests as it involves multiple hormones
what is the cuase of endocrine problems that are not to do with the pituitary?
parathyroid issues
primary hyperparathyroidism
cancer
certain drugs
clinical presentation of hypercacaemia?
thirst and increased urine output
constipation
abdominal pain
what is the structure of steroid hormones?
3 six sided carbon rings and 1 five sided carbon ring
how do steroid hormones work?
move through cell membrane and bind to receptors in the nucleus or cytosol
the hormone receptor complex acts as a transcription factor causing mRNA to be transcribed
what is conns syndrome?
when adrenal gland makes too much aldosterone
leads to high blood pressure
