digestive tract histology Flashcards
esophagus: epithelia type?
nonkeratinized stratified squamous epithelium
esophagus: upper 1/3 exists of?
striated muscle
esophagus: middle and lower 1/3 exists of?
smooth muscle
where in the esophagus striated muscle?
upper 1/3
where in the esophagus smooth muscle?
lower 1/3
nonkeratinized stratified squamous epithelium
which part of digestive tract?
esophagus
stomach: wat color are parietal cells in histology?
pink (eosinophilic)
stomach: what color are chief cells in histology?
dark purple red (basophilic)
stomach: what type of exocrine cells?
parietal cells: secrete gastic acid
chief cells: secrete pepsinogen (inactive form; cleaves proteins)
parietal cells: role?
secrete gastric acid
which cells in stomach secrete gastric acid?
parietal cells
chief cells: role?
secrete pepsinogen
which cells in stomach secrete pepsinogen?
chief cells
chief cells: where in stomach?
at the base of glands
in fundus and corpus
what does pepsinogen do?
inactive form of pepsin
digests proteins
what does the duodenum have to increase the absorptive surface?
villi and microvilli
plicae circulares
villi and microvilli: role?
increase absorptive surface
what kind of glands in duodenum?
Brunner glands
secrete bicarbonate
what do Brunner glands do?
secretes bicarbonate
protects the mucosa from acidic stomach contents
where are the Brunner glands located?
in the submucosa of the duodenum
what kind of crypts in duodenum?
crypts of Lieberkuhn
what is the role of the crypts of Lieberkuhn?
contain stem cells
replace enterocytes, goblet cells, Paneth cells
what do Paneth cells secrete?
antimicrobial compounds: defensins, lysozyme, TNF
which cells in the duodenum secrete antimicrobial compounds?
Paneth cells
which cells in the duodenum play a role in the innate immune system?
Paneth cells
what can you find in the distal duodenum? (anatomically)
plicae circulares
plicae circulares: where in duodenum?
distal duodenum
everywhere in digestive tract except in first portion of the digestive tract
plicae circulares: function?
increase surface area
spiral/circular folds in the digestive tract
jejunum: histology?
villi, crypts of Lieberkuhn
what kind of crypts in jejunum?
lieberkuhn
how are the plicae circulares different in the jejenum compared to the ileum?
more numerous and taller (more prominent)
where are plicae circulares more prominent?
jejunum
jejunum: appearance on CT with oral contrast?
feathered
which part of the gut has a feathered appearance on CT with oral contrast?
jejunum
duodenum: histology?
villi and microvilli, Brunner glands, crypts of lieberkuhn, plicae circulares
ileum: histology?
villi, Peyer patches, crypts of lieberkuhn, plicae circulares
largest number of goblet cells
goblet cells: role?
secrete mucus
where are the largest number of goblet cells in the gut?
ileum
where can you find crypts of lieberkuhn?
between villi of the small intestine (duodenum, jejunum, ilieum)
also in colon
where can you find villi (and microvilli) in the gut?
duodenum, jejunum, ileum
not in colon
where are Peyer patches?
ileum
what are Peyer patches?
submucosal lymphoid follicles
contain M cells
Role of M cells in Peyer patches?
transport antigens to underlying lymphoid follicles -> start immune response
villi, peyer patches, plicae circulares, crypts of lieberkuhn.
where?
ileum
villi, crypts of lieberkuhn, prominent plicae circulares
where?
jejunum
villi, Bunner glands, crypts of lieberkuhn, plicae circulares
where?
duodenum
colon: are there villi?
no
colon: histology?
crypts of lieberkuhn, abundant goblet cells
no villi
where are goblet cells abundant?
colon
which part of the intestine has no villi?
colon