histology of the pituitary gland, pineal gland, parathyroid gland and endocrine pancreas Flashcards
what is the 1 quality all endocrine organs have?
- all have rich vascular supply
do endocrine glands discharge their secretions into ducts or directly into the circulation?
all discharge their secretions directly into circulation
which endocrine glands are NOT epithelial?
posterior pituitary
pineal
what is the posterior pituitary gland made of?
it is a down growth of hypothalamus
neural tissue containing axons and glial cells
what hormones does the posterior pituitary gland store and secrete?
where is this hormone produced?
oxytocin and antidiuretic hormone
produced in hypothalamus
what are the specialised glial cells within the epithelium of the anterior pituitary gland?
pituicytes
what are the top 3 most common types of pituicyte within the epithelium of the anterior pituitary gland?
- somatotrophs (50%)
- lactotrophs
- corticotrophs
what hormone does somatotrophs of the anterior pituitary gland produce?
growth hormone
what hormone does lactotrophs of the anterior pituitary gland produce?
prolactin
what features of the lactotroph cells make them identifiable?
-
- recognised by cytoplasm having extending processes wrapping round other cells
what is the least common cells in the anterior pituitary?
thyrotrophs
where is the pineal gland located?
on posterior end of the corpus callousum in brain
what is the identifiable feature of the neural tissue of the pineal gland?
made of lobles of pinealocytes arranged in rosettes
has brain sand along edges
what is the brain sand of the pineal gland?
- accumulation of calcium along the edges
- increases with age
what hormone does the pineal gland secrete?
melatonin
what are the 2 identifiable feature of the epithelial tissue of the thyroid gland?
- the colloid (circular spaces between the follicular epithelial cells)
- the presence of calcium oxidate crystals
what hormone is produced by the thyroid gland?
- thyroxine
- calcitonin (by C cells)
what hormone does the parathyroid gland produce?
parathyroid hormone, PTH
involved in calcium homeostasis
what are the 3 types of cell within the parathyroid gland?
which is the functional cell?
- chief cells - functional cells
- oxyphils
- adipocytes
what are the 2 identifiable features of the epithelial tissue of the parathyroid gland?
- scant cytoplasm
2. NO calcium oxidate crystals
what structures make up the endocrine pancreas epithelium?
the isle of langerhans
what are the 5 hormones secreted by the isle of langerhans?
- insulin
- glucagon
- somatostatin
- pancreatic polypeptide
- grelin
INSULIN:
- which cells produce it within the isle of langerhans of the pancreas?
- what is its action?
- secreted by beta cells
- lowers blood glucose conc
GLUCAGON
- which cells produce it within the isle of langerhans of the pancreas?
- what is its action?
- secreted by alpha cells
raises blood glucose by making liver break down glycogen (hepatic glycogenolysis)
