Endocrine Flashcards
what is diabetes insipidus
insufficiency or failure to respond to ADH
features of diabetes insipidus
polydipsia, polyuria, thirst
hypernatraemia, dilute urine
treatment of primary diabetes insipidus?
desmopression - ADH analogue
what does primary organ dsyfunction mean?
abnormality in target organ
what is secreted in the anterior pituitary gland?
TSH ACTH GH Prolactin LH + FSH
what is secreted in the posterior pituitary gland?
stores ADH
produces oxytocin
describe the anatomy of the adrenal gland
adrenal cortex and adrenal medulla
describe the anatomy and function of the adrenal cortex
glucocorticoids - zona fasicularis
mineralcorticoids - zona glomerulosa
androgens - zona reticularis
what is the function of glucocorticoids
stress response, immune response, metabolism and other life functions
function of mineralcorticoids
electrolyte regulation
blood pressure
vascular volume
what is made in the adrenal medulla?
catecholamines like epinephrine, norepinephrine and dopamine
what happens in congenital adrenal hyperplasia?
group of conditions, causing either over or under production of mineralcorticoids or androgens, most commonly due to faulty gene for 21 hydroxylase
symptoms in over production of androgens in congenital adrenal hyperplasia?
clitoral megaly, shallow vagina, menstrual irregularity,
precocious puberty, infertility, excessive facial/pubic hair, rapid childhood growth
males - normal penis but aspermia
what is Conn’s syndrome?
hyperaldosteronism - hypernatraemia and hypokalaemia
what is phaeochromocytoma?
tumour producing too much catecholamines
which of the thyroid gland is the active hormone?
T3
why does sick euthyroidism happen?
enzyme that converts T4 to T3 is found in tissue throughout the body, when the body is under stress, it stops producing the enzyme causing increase in T4 but normal or reduced T3
what happens in Graves disease
antibodies made that bind to TSH receptors in thyroid gland, producing excess T4/T3
what happens in complete androgen insensitivity syndrome?
46XY male that has a defect in testosterone receptors, thus causing failure of male sexual characteristics to develop
what happens in turners syndrome?
45X chromosome defect, causing deficiency estrogen which results in a host of symptoms
what must be considered when measuring hormone levels?
time of day and the natural diurnal variations of hormones
how is calcium regulated?
drop in ca2+ is sensed by parathyroid, releasing PTH in response.
rise in ca2+ is sensed by thyroid gland releasing calcitonin in response
what functions does PTH have
increase osteoclast activity, increasing bone resorption
stimulating renal activation of vitamin D which leads to increased gut absorption of calcium
increase renal absorption of calcium from urine
how is vitamin D made
through sunlight in the skin it is converted from precursors and sent to the liver and finally the kidney where it is activated into calcitriol which increases gut absorption of calcium