10/1 Histology!!! Flashcards
what are the two important hormones produced by DNES cells in the duodenum
secretin, and cholecystokinin
Cellular mechanism of exocrine secretion where portion of cell pinches off (exmp. mammary gland)
Apocrine
cellular mech. of exocrine secretion where entire cell ruptures
Holocrine
mech of exocrine where exocytois of vesicles and membrane transport of salt and water (sweat and salivary glands)
Merocrine
secretion into the blood stream
endocrine secretion
small saclike smewhat spherical structure
acinar or alveolar
long, non sacklike organization of exocrine gland
tubular
an inactive enzyme precursor
zymogen
what are the exocrine portions of the pancreaus?
the pancreatic acinus cells that are in a round sac like structure around the intercalated duct and dump right into the ducts to go to the tralobular ducts to the main pancreatic duct etc.
The endocrine portions of the pancreaus
not associated with the ducts, and are little islands or Islet of langerhans cells
what is the histological structure of the pancreus?
Acinar cells around the ducts with light staining with big nucleus. centroacinar cells (CA) that are light staing cells all by themselfs in the tissue. Intercalated ducts, that are light staining regions without nucleus!
Store zymogens and enzymes in seretory granules: trypsinogen, chymotrypsinogen, carboxypeptidase, amylase, lipase, DNase, RNase
Pancreatic acinar cells
what do pancreatic acinar cells store?
Store zymogens and enzymes in seretory granules: trypsinogen, chymotrypsinogen, carboxypeptidase, amylase, lipase, DNase, RNase
how to stimulate secretion from pancreatic acinar cells
cholecystokinin CCK from DNES cells of the duodenum
what are the ducts from the acinar cells in the pancrius and what ducts do they lead to?
intercalated ducts in parenchyma and interlobular in stroma. (no striated ducts like in the salivatory glands
secrete HCO3- rich fluid to keep zymogen inactive by maintaining pH >7.5
centroacinar cells (the cells that start the ducts in the acinar cell region) and intercalated ducts
secretion is principally via an exchanger for keeping the pH high in the ducts of the pancreus what is the exchanger
a Cl- / HCO3- exhcanger
what regulates the Cl-/HCO3 exchanger in centroacinar cells
CFTR
what stimulates the Centroacinar cells (CA) and ducts?
secretin
what is the duct that goes through the connective tissue through the pancreus
Interlobular ducts
what are the cells that if lost would make the pancreus no longer an endocrine pancreas?
islets of langerhans
what gives the islet of langerhans cells the ability to act as an endocrine cell
the presence of lots of fenestrated capillaries
what is a fenestrated cappilary?
have pores or “windows” in them but not big holes like the sinusoid
what is the homone in alpha cells
glucagon
what is the homone in beta cells
insulin
what is the hormone secreted by delta cells?
somatostatin
inhibit alpha and beta cells
somatostatin
what are the % of different islet cells
30% Alpha / 65% Beta / 4% Delta
anything which leads to zymogens being activated in the pancreas leads to auto-digestion of pancreatic tissue, inflammation, and intense epigastric pain
Acute pancreatitis
cancer more common in females, 3% of all, and poor prognosis
pancreatic carcinomas