endocrine anatomy Flashcards
where is the pituitary gland located?
beneath hypothalamus at base of skull
pituitary gland lobes
anterior + posterior
what does the hypothalamus control?
synthesis and secretion of pituitary hormones
pituitary gland: anterior lobe
secretes 6 hormones
*thyroid stimulating hormone
*adrenocorticotropic hormone (ACTH)
pituitary gland: posterior lobe
secretes 2 hormones
*antidiuretic hormone (aka vasopressin)
*oxytocine
antidiuretic hormone (ADH)
released in response to high serum osmolality and/or hypotension
function: causes water retention via action in kidneys
“ADH- this hormone stops the pee pee”
where are the adrenal glands located?
sit on top of kidneys
what is each adrenal gland composed of?
inner medulla and outer cortex
what does the adrenal medulla secrete?
epinephrine and norepinephrine
2 catecholamines in response to SNS stimulation
epinephrine and norepinephrine
enhance effects of SNS
“fight or flight”
in response to ACTH, the adrenal cortex secretes…
glucocorticoids
mineralocorticoids
sex steroids
steroid hormones secreted by the adrenal cortex
essential for life
regulate body’s response to normal and abnormal levels of stress
made on demand and not stored in cells
“three S’s: sugar, salt, and sex”
glucocorticoids: principal hormone
cortisol
hormones are named for primary effect of glucose metabolism, but they effect all tissues of the body
5 functions of glucocorticoids
- raise blood sugar (oppose insulin)
- protect against physiologic effects of stress
- suppress inflammatory and immune processes
- release muscle stores of proteins
- increase blood cholesterol
mineralocorticoids: principal hormone
aldosterone
mineralocorticoids are regulated by
the renin-angiotensin system in kidneys
functions of mineralocorticoids
-maintain salt and water balance
-promote secretion of K+
what happens when aldosterone is triggered by angiotensin II?
aldosterone promotes sodium retention –> leading to water retention
thyroid
butterfly shaped gland in neck
secretes triiodothyronine (T3) and thyroxine (T4) – produces 80-90% more T4 than T3
T3
triiodothyronine
active form – converted FROM T4
T4
two forms
-1 attaches to proteins when not needed
-free T4 enters tissue when needed
T4 converted to T3 when it reaches organs and tissues to aid in metabolism
iodine
necessary component in synthesis of thyroid hormone
euthyroid
normally functioning thyroid gland
parathyroid gland
4 pea-sized glands within thyroid tissue of neck
produce and secrete PTH in response to hypocalcemia and break down of bone to reestablish normal calcium in the blood
promote vitamin D production
