Med 1 EOR - GI Flashcards
what do the different cells of the stomach secerete? (parietal, chief)
parietal: HCl - dissolves food, activates pepsin, stimulates duodenal enzyme release, kills food bacteria
chief: pepsinogen (prehormone to pepsin) - digests proteins
what does the pancreas release for negative feedback of digestion?
somatostatin –> inhibits secretion of gastrin, insulin, glucagon, pancreatic enzymes and inhibits gallbladder contraction
where does MOST of the small intestine absorption take place?
duodenum
what is secretin? (Where does it come from and what does it do?) what is the secretin test for?
Secretin: duodenum release secretin → inhibits parietal cell gastrin/HCl production → stim pancreas to release bicarb (buffer)
*clinical pearl: secretin test = reduced gastrin levels EXCEPT in Zoster-Ellison syndrome.
what 3 things does cholecystikinin do?
- stimulates pancreatic release of digestive enzymes (trypsin, amylase,lipase) = helps breakdown fats + proteins.
- Increase bicarb release (pancreatic enzymes work best in buffered -basic environment)
- Stimulates gallbladder contraction + bile release. Bile salts → emulsify fats into smaller micelle (to make breakdown by lipase easier)
excorine pancreas: what 4 substances do the acinar cells produce?
amylase, lipase, proteases (trypsinogen and chemotrypsinogen), bicarb
endocrine pancrease: what 3 substances do the islets of langerhan’s produce?
insulin, glucagon, somatostatin
MC cause of esophagitis? what are other causes?
GERD. also infectious (candida, CMV, HSV), meds (NSAIDS, etc), radiation, eosinophilic
odynophagia, dysphagia, retrosternal chest pain. Kids- feeding difficulty.
Hematemesis + dyspnea w/ corrosive ingestion
esophagitis
MC type of esophageal CA in the world , which part of the esophagus is it most commonly found?
Squamous: MC worldwide, MC in upper ⅓ of esophagus.
MC type of esophageal CA in the US? what is the typical pt?
Adenocarcioma: MC young, obese, Caucasian. Usually a complication of GERD → Barret’s esophagus.
Upper endoscopy = superficial longitudinal mucosal erosions. Dx?
mallory weiss tear
txt options for mallor weiss tear
supportive (most stop bleeding w/out intervention). Acid suppression promotes healing. If severe bleeding → epi injection, sclerosing agent, band ligation, hemoclipping or balloon tamponade
pathophys of achalsia
idiopathic loss of Auerbach’s plexus (usually produce inhibitory nitrous oxide to relax smooth muscle) → incr. LES pressure → lack of peristalsis + obstruction. → dilation if untreated.
best first line to Dx pyloric stenosis?
US
symptoms achalasia
dysphagia solids and LIQUIDS.
Dx of achalasia (2 ways)
esophageal manometry (GOLD std) = pressure >40 mmHg + decr peristalsis. Double contrast esopahgram = “birds beak”
txt options for achalasia
botox lasts 6-12mo, nitrates, CCBs, pneumatic dilation, esophagomyomectomy.
unknown cause. EXCESSIVE contraction of esophagus w/ peristalsis
S+S: dysphagia (solids + LIQUIDS), CP, maybe asympt.
nutcracker esophagus
Dx of nutcracker esophagus
manometry = incr pressure DURING peristalsis
txt options for nutcracker esophagus
CCBs, nitrates, botox, sildenafil
patho of zenckers diverticulum?
pharyngoesophageal pouch (false diverticulum, only involves mucosa) weakness of jxn between cricopharyngeus muscle + lower inferior constrictor → herniation/outpouch.
Dx of zenker’s diverticulum is best made with what?
barium esophagram
txt options for zenker’s diverticulum
diverticulectomy, cricopharyngeal myotomy. Observe if small and asymp.