GI tract Flashcards
what are salivary glands?
submandibular
parotid
sunlingual (below tongue)
what are parts of small intestine?
duodenum
jejunum
ileum
what are parts of large intestine?
cecum ascending colon transverse colon descending colon sigmoid colon
what are parts of stomach?
pylorus antrum fundus cardia body
what happens in hirschprungs ?
enlarged colon
myenteric plexus loss (all or some of colon has no innervation)
what are endocrine cells?
Gcells - release gastrin (stimulate parietal cells)
Dcells - secrete somatostatin (inhibit gastrin release)
Enterochromaffin like cell - secrete histamine (stimulate acid secretion)
what does prostaglandin inhibit?
histamine
what virus can cause ulcers?
H.pylori
what else can cause ulcers?
coffee+alcohol (stimulate parietal cells)
non-steroidal antiinflammatory sdrugs (NSAIDS)
- these decrease prostaglandin levels which decreases inhibition of histamine (more acid secretion)
what does gastric juice contain?
water + ions HCl ( low PH) pepsinogen (proenzyme of pepsin) instrinsic factor (glycoprotein) mucus gastrin (regulates acid secretion )
why is stomach PH low?
prevents bacterial growth
catalyses cleavage of PEPSINOGENS to PEPSIN
what are gastric secretion phases?
Cephalic phase
gastric phase
intestinal phase
What are GI tract layers?
mucosa
submucosa
muscular
serosa
what are ducts?
intercalated
striated
excretory
what are saliva compounents?
water, enzymes, proteins, mucus,
what does parietal cell do?
H+ and Cl- secretion against conc gradient (has lots of mitochondria)
adic secretion
what is difference between amino acid and peptide transport?
Amino acid is Na dependent
peptides are H dependent
where do proteins, carbs and lipid go to when digested?
proteins + carbs - hepatic portal vein
lipids - lacteal system (can reform in cells as chylomicrons)
what are disacharides broken into?
maltose - glucose + glucose
sucrose - glucose + fructose
lactose - glucose + galactose
what are peyers patches?
areas of lymphoid tissue - local immune response in large intestine
how is saliva produced?
acinar cells produce primary saliva
pass through intercalated and striated ducts
modified by ductal cells
myoepithelial cells contract and eject saliva into mouth
