Stomach and Intestins Flashcards
gastroesophageal junction epithelial transition
stratified squamous to simple columnar
layers of stomach, internal to external
mucosa
submucosa
muscularis externa
adventitia
mucosa lining
simple columanar mucous secreting cells
layers of muscularis externa
inner oblique
middle circular
outer longitudinal
gastric pits of body and fundus
short pits
elaborate glands
cell types and their location in gastric pits
mucous neck cells- upper parietal cell- upper 2/3 chief cells- base neuroendocrine cells- base stem cells-base
parietal cell function
HCl and Intrinsic factor secretion
intercellular cannaliculi
tubule system in parietal cells where HCl acumulates
stimulators of parietal cell secretion
gastrin
ACh
histamine
inhibitors of parietal cell secretion
proton pump inhibitors
histamine receptor blockers
autoimmune gastritis
autoantibodies against parietal cells or blockage of IF binding to B12
pernicious anemia
anemia caused by autoimmune gastritis caused deficiency of B12
function of chief cells
secrete digestive enzymes (pepsinogen)
function of neuroendocrine cells
regulate water and electrolyte metabolism enzyme secretion GI motility mucosal growth other hormone release
gastric pits of cardiac stomach
short pits and glands
cells in cardiac stomach
surface mucous
mucous neck
some parietal
gastric pits of pyloric stomach
long pits, short glands
cell types of pyloric stomach
mucous cells- lots
neuroendocrine cells- gastrin and somatostain
gastritis triggers
NSAIDs alcohol cigarettes stress hormones bile reflux into stomach
helobactor pylori
type of bacteria that can cause gastritis because it attaches to surface epithelium and destroys the mucous coat resulting in ulcerations from HCl contacting unprotected surface epithelium
zollinger-ellison syndrome
gastrin secreting tumor in pancreas (or stomach) which causes high HCl section which results in ulcers and inactivation of pancreatic enzymes–> sterratorea and diarrhea
areas at risk of dysplasia, neoplasia, and metaplasia
gastroesophageal junction
below pectinate line of anus
gastroduodenal junction epithelial transition
simple columnar epithelium
switch from secretive to absorptive
pyloric sphincter formed by thickening of inner circular layer of muscle
plicae
permanent visible folds in small intestine submucosa
layers if SI muscular externa
inner circular
outer longitudinal
enterocyte function in SI
simple columnar absorptive
have microvilli to increase the surface area with brush boarder enzymes to finish digestion
also coat and secrete IgA
goblet cells of SI
secrete mucous
crypts of Lieberkuhn
intestinal glands of columnar absorptive cells, goblet cells, panted cells, stem cells, and M cells
M cell function
antigen presenting
panted cell funciton
secrete lysozymes, defensins, ang glycoproteins
characteristics of duodenum
short villi and runners glands
ampulla of Vater
valve where bile and pancreatic enzymes enter duodenum
sphincter of oddi
smooth muscle thickening where bile and pancreatic enzymes enter duodenum
neuroendocrine cells in duodenum release
secretin which stimulates pancreatic d cut cells to release bicarb
cholecystokinin- stimulates pancreatic secretion and gallbladder contraction
brunner’s glands
alkaline mucous secreting cells in submucosa of duodenum
characteristics of jejunum
most pronounced place
long vili
no runner’s glands of peyer’s patches
peyer’s patches
MALT bunches that extend into the lamina propr. of the Ileum
characteristics of the Ileum
broad, flat, short microvilli
Peyer’s patches of MALT
tiena coli
outer longitudinal muscle of colon arranged into 3 bands
area of GI tract with most goblet cells
colon
features of colon
no villi lots of goblet cells crypts of lieberkuhn no lymphatic vessels collagen layer under basal lamina
lower 1/3 of rectum
anal canal
features of anal canal
anal columns
anal sinuses
anal valves
highly innervated
pectinate line
where anal canal epithelium switches form simple columnar to stratified squamous
location of hemmorrhdial venous plexus
submucosa of anal canal
internal anal sphincter
inner circular layer thickening of muscular external of anal canal
anus features
keratinized stratified squamous
circumanal glands
muscularis external of skeletal muscle
malabsorptive syndromes and possible causes
poor absorption of fat, protein, carb, salts or water
brush boarder defects
defective bile secretion
abnormal pancreatic enzymes
gluten enteropathy
immune mediated inflammatory response of SI resulting in atrophy and flattening of villi and hyperplasia of intestinal glands
cause of malabsorptive syndrome
diverticular disease
high intraluminal pressure (poor diet fiber) and weakened muscle leads to a mucosa herniation- pocket where bacteria can accumulate and lead to infection and inflammation and possible perforation and hemorrhage
crohn’s disease
chronic inflammation of small intestine (ileum)
patch ulceration siwth normal mucosa between, may have domed areas of edemas mucosa and submucosa
inflammation can be transmural
ulcerative colitis
affects colon and rectum
acute phases with intermittent remission
lots of inflammation but rarely transmural
high rate of dysplasia and adenocarcinoma in chronic cases
inflammatory pseudopolyps
seen in ulcerative colitis
superficial ulcers with normal mucosa above the ulcerations
colon polyps
benign adenomas with varying degrees of dysplasia
adenocarcionma
malignant adenomas, commonly found in sigmoid colon
appendix
same as colon, just smaller diamater
lymphoid tissue in submucosa
appendicitis
acute inflammation with surface ulcerations and exudates
possible to spread through all layers and into peritoneum–> peritinitis
