G.I. 2 organs Flashcards
(26 cards)
extramural
glands outside of the gut tube
functional unit of the pancreas
secretory acinus (exocrine) islet (endocrine)
4 enzymes secreted by the acinar cells
zymogens: trypsinogen, trypsin inhibitor, amylase, ribonuclease, lipase
centroacinar cells
the first duct cells overlapping the acinar cells, secreting bicarbonate in response to secretin- REDUCES pH of LUMEN AND SOLUBLIZES EXCRETIONS
morphology of intercalated, intralobular (Secretory), interlobular cells
low cuboidal and cuboidal and low columnar respectively.
what causes pancreatic acini to secrete
CCK and vagal stimulation (paracrine/ACh)
Alpha cell function and location
secretes glucagon (to signal liver to break down glycogen) - more toward the edge of islet
Beta cell function and location
secretes insulin (antagonist to Alpha cells) signals liver to take up glucose- more in center of islet
Delta cell function and location
secretes paracrine somatostatin to pull down secretions from both B and A type cells- throughout islet/ more peripheral
why are liver sinusoidal epithelia unique
they contain both simple squamous and Kupffer cells (fixed macrophages)
why is hepatocyte sER well developed
buecause of glycogen production, detoxification
what are the 3 types of hepatocyte junctions
cell-to-cell, bile canaliculi, perisinusoidal space of Disse
to what direction does the space of Disse flow
toward the lymph of the triad
describe the polarity of acinar cells
that are basophilic on the basal laminar side (rER) and zymogen granule containing on their apical side
how are endocrine portions of pancreas hsitologically distinguished from exocrine portions
islets are paler staining, more vascular
portal area
the hilus of the liver that brings arterioles, portal venules, lymph and bile together in a CT septa throughout the hepatocyte plates
All constituents of the portal are flow toward the central vein EXCEPT…
bile and lymph
what space leads to the gall bladder
the Canal of Hering from the bile canaliculi between hepatocytes
Space of Mall
where the perisinusoidal Space of Disse empties to lymph vessel
functional unit of the liver
lobule
what type of surface modification do hepatocytes have
microvilli (absorption, secretion), tight junctions between bile canaliculi
The layers of the gallbladder
simple columnar epithelium, lamina propria, muscularis, adventitia/serosa
profile of the gallbladder
mucosal folds
what about the smooth muscle of the gall bladder differs from all other smooth muscle
it responds to CCK
