AP02 - histology of the endocrine glands Flashcards
Where are protein hormones normally stored?
secretory granules
What is the only gland to store its’ products extracellularly?
Thyroid
What does the thyroid follicle lumen contain?
colloid
What are thyroid follicles surrounded by?
parafollicular cells (secrete calcitonin)
What is the thyroid follicle made of?
a ring of thyrocytes
What do the thyroid follicles do?
add iodine to thyroglobulin
What kind of cells are in the parathyroid?
Principal and oxyphil cells
With age, what happens to the parathyroid?
It enlarges and becomes more fatty
Where are alpha cells located?
on the peripheries of the islets of langerhans
What do delta cells secrete?
Somatostatin
What do PP cells secrete?
pancreatic polypeptide
What is the role of the zona glomerulosa?
make mineralcorticoid, including aldosterone
What is the role of the zona fasciculata?
secrete glucocorticoids, including cortisol
What is significant about the blood vessels through the adrenal cortex?
They have fenestrations, allowing hormones in
What cells does the adrenal medulla contain?
medullary parenchymal cells
What are chromograins?
bindings of granules containing catecholamines in the adrenal medulla
What are parenchymal cells innervated by?
preganglionic sympathetic neurones, triggering release of catecholamines in stress
What are the 5 cell type in the pituitary gland?
Somatotrophs Lactotrophs Gonadotrophs Thyrotrops Corticotrophs
What do somatostrophs secrete?
Somatotrophin (Growth hormone) (growth in epiphyseal plates)
What do lactrophs secrete?
Prolactin
What do Gonadotrophs secrete?
FSH and LH
What do thyrotrophs serete?
Thyrotropin (TSH)
What do corticotrophs secrete?
Adrenal corticotropin
What is the difference between regulated and constitutive secretion?
Regulative is hormone controlled, where constitutive secretion responds directly to the immediate surroundings
