GI III Flashcards
gastric acid secretion from parietal cells
stimulus - ACh, gastrin, histamine
- M3 - ACh / gastrin - CCK-B / histamine - H2
- most important - ECL histamine release
- mechanism - cAMP and IP3/Ca stimulate H/K ATPase
inhibit - prostaglandin and somatostatin
decreased cAMP
alkaline tide
with gastric acid secretion
- carbonic anhydrase - convert CO2 and H2O
- to H and HCO3
H - secreted to gastric lumen
HCO3 - bicarb - secreted to blood - alkaline tide
pancreas secretion
a-amylase - starch digestion
lipase - fat digestion
proteases - secreted as proenzymes
trypsinongen - converted to active trypsin
trypsinogen activation
from pancreas
-converted to trypsin by enterokinase - brush border of duodenum/jejunum
active form - trypsin - activates other pancreas proteases
carb absorption
monosacchaides - absorbed enterocytes
glucose and galactose - SGLT1
fructose - facilitated diffusion - GLUT 5
all transported GLUT-2
iron absorption
duodenum
folate absorption
small bowel
B12 absorption
terminal ileum - with IF
peyer patches
M cell - APC
B cells to IgA plasma cell in germinal centers
rate limiting step bile acid synthesis
7a hydroxylase
bilirubin metabolism
heme to biliverdin - by heme oxygenase
biliverdin to bilirubin
unconjugated - not soluble - indirect
-in blood complexed albumin
conjugated with glucuronate - soluble - direct
UDP glucuronosyl transferase
unconjugated to conjugated bilirubin
warthin tumor
papillary cystadenoma lymphomatosum
B9 cystic tumor with germinal center
salivary gland - often parotid
MC salivary gland tumor
pleomorphic adenoma
chrondromyxoid stroma
achalasia
failure LES - loss of myenteric (auerbach) plexus
dysphagia - solid and liquid
bird beak - barium swallow
obstruction dysphagia
solid only
secondary achalasia
with chagas disease - t. cruzii
or malignancy
boerhaave syndrome
wretching - transmural tear distal esophagus
get pneumomediastinum - air
esophageal stricture
lye and acid reflux
punched out lesion HIV esophagitis
HSV-1
linear ulcer HIV esohpagitis
CMV
plummer vinson syndrome
dysphagia, iron deficiency, esophagus webs
risk of esophageal SCC
barret esophagus
stratified squamous to intestinal
nonciliated columnar with goblet cells
esophageal cancer
worldwide - SCC more common
-upper 2/3
adenocarcinoma - in US
-lower 1/3
SCC of esophagus risk fx
zenker diverticula alcohol esophageal web hot liquid cigarette
adenocarcinoma of esophagus risk fx
barret
obesity
GERD
parts of stomach
cardiac - GE junction
fundus - top
body - main
antrum - pyloric sphincter - near duodenum
acute gastaritis
loss mucosa barrier - inflammation
NSAID - low PGE2
burns - curling ulcer
brain injury - cushing ulcer - increased vagal - more ACh
cushing ulcer
with brain injury
increased vagal stimulation - more ACh - more H+
chronic gastritis
non-erosive
type A - fundus/body - autoimmune
type B - antrum - h. pylori
h. pylori
infect antrum of stomach
-get chronic gastritis
risk of MALToma
menetrier disease
gastric hyperplasia of mucosa
precancerous
hypertrophic rugae - look like brain gyri
virchow node
left supraclavicular
with mets from stomach
krukenberg tumor
B/L stomach ca mets to ovaries
mucin secreting, signet ring cells
sister mary joseph nodule
subQ periumbilical mets
from stomach ca
intestinal stomach cancer
h. pylori smoked foods -nitrosamine tobacco smoking achlorhydria chronic gastritiis
commonly - lesser curve
diffuse stomach cancer
signet ring cell - stomach wall grossly thick and leathery
-linitis plastica
gastric ulcer
worse with meals
weight loss
NSAIDs
duodenal ulcer
better with meals
weight gain
ZES
posterior wall duodenum ulcer
gastroduodenal a
gastric ulcer lesser curve stomach
left gastric a
