Exam 3- Histology of the Adrenal, Thyroid, and Parathyroid Glands Flashcards
what are the two main regions of the adrenal gland?
cortex and medulla
what does the adrenal cortex produce?
steroids
what does the adrenal medulla produce?
catecholamines
what does the adrenal cortex regulate?
carbohydrate, lipid, and protein metabolism
what does the adrenal medulla regulate?
acute response to stress “Fight or Flight” response
what are the three layers of the adrenal cortex?
zona glomerulosa
zona fasiculata
zona reticularis
what does the zona glomerulosa secrete?
aldosterone
what does the zona fasciculata produce?
steroid hormones (especially cortisol or corticosterone in response to ACTH)
what does the zona reticularis produce?
gonadocorticoids (androgens) and less glucocorticoids
do steroid secreting cells in the adrenal cortex have secretory granules?
no
do steroid secreting cells in the adrenal cortex have more smooth or rough endoplasmic reticulum?
much more smooth endoplasmic reticulum
what type of capillaries supply the adrenal cortex?
fenestrated
what cell types are in the thyroid gland?
thyroid follicular cells
parafollicular cells
what is a thyroid follicle filled with?
pink colloid containing thyroglobulin, a hormone precursor
what does thyroid stimulating hormone do?
stimulates thyroid to secrete thyroid hormone
how many parathyroid glands are there?
four, external/upper and internal/lower glands
what does the parathyroid gland produce?
parathyroid hormone (PTH)
what does parathyroid hormone do to calcium levels?
increases blood calcium
what does the adrenal medulla’s acute response to stress lead to?
fight or flight
increased blood glucose and free fatty acids
increased blood pressure, heart rate/output, blood flow to skeletal muscle
what are catecholamines from the adrenal medulla secreted in response to?
cholinergic stimulation by preganglionic sympathetic fibers
what do steroid secreting cells have?
some rough ER
extensive smooth ER
mitochondria with rounded cristae
lipid droplets
coated pits- LDL uptake
what do peptide/protein secreting cells contain?
lots of rough ER and Golgi
little smooth ER
mitochondria with skinny, elongated cristae
secretory granules
what cells do not have secretory granules?
adrenal cortex cells
thyroid cells
pineal gland
leydig cells (testis)
granulosa cells (ovary)
what brings arterial blood to medullary capillaries in the adrenal gland?
medullary arterioles
what is the sequence from the hypothalamus for stimulating the thyroid?
thyrotropin releasing hormone
thyrotropes in pars distalis to release thyroid stimulating hormone
stimulates thyroid to secrete thyroid hormone
what does thyroid hormone inhibit?
pituitary and hypothalamus
what do apical microvilli in the thyroid contain?
peroxidase
why are oxyphil cells eosinophilic?
lots of mitochondria
what cells release calcitonin?
parafollicular cells
do parafollicular cells have granules?
yes
