105b stomach and intestines histo Flashcards Preview

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Flashcards in 105b stomach and intestines histo Deck (12)

what are the folds inside the stomach when it's empty called?

rugae - due to contraction of muscularis mucosae


3 general regions of the stomach - top to bottom



how many muscles layers are in the stomach muscularis externa?

3 - inner oblique, middle circular, outer linear
churning motion


what is the functional gland of the stomach?

gastric glands - mostly in fundic later


cell types of the gastric glands (top to bottom) and function

surface mucous cells (washed out, secrete mucous which coats surface and protects cells via mucinogen granules on apical side)
neck mucous cells (different type of mucous)
parietal cells (pink cells, secrete intrinsic factor (B12) + HCl, large pyramidal cells with many mito, extensive network)
chief cells (dark stain, secrete pepsinogen)
enteroendocrine cells (hormones secretion at basal surface)


regional difference in glands for the stomach - cardiac/pyloric vs fundic

fundic more parietal and chief cells
cardiac/pyloric more mucous cells with deeper pits


where are new are new gastric epithelial cells made?

isthmus - neck of gastric gland


what are the specialized structures in the intestine?

plicae circularis (mucose + submucosa)
villi (core has lamina propria with vessels and lacteal)
microvilli (part of enterocytes)
glands/crypts - invaginations


brunner's gland - location, function

in duodenal submucosa
secrete alkaline mucus


intestinal absorptive cell

simple columnar epithelial
microvilli (actin-bundle scaffold) at apical side
tight junctions seal off cell


lipid absorption in intestine

1) micelles w/ FFA (from lipases) enter via brush border
2) FFA re-esterified to make triglycerides and cholesteryl esters
3) combined with apo-lipoproteins to make lipoproteins (chylomicrons)
4) chylomicrons secreted to lacteals and capillaries


protein absorption

1) pepsin (from chief cells) breaks proteins into polypeptides
2) polypeptides break down into aa's via pancreatic proteases
3) aa enter via enterocyctes via carrier in brush border
4) aa's used to build proteins or exit basolater membrane