Gut Physiology Flashcards
L (anterior) vagus nerve gives:
R (posterior) gives:
L with hepatic branch
R w celiac branch and the ‘criminal nerve of grassi’ can lead to elevated acid levels post vagotomy
Chief cells produce…
Pepsinogen (converted to pepsin) which initiates proteolysis
Parietal cells produce…
H+ and intrinsic factor which binds B12 and is absorbed in terminal ileum
Acetylcholine (Ach), gastrin and histamine are main stimuli for…
H+ production
Ach (vagus) and gastrin activate… to increase… which activates… which increases…
activate PIP, DAG to increase Ca, activates protein kinase C, which increases Hcl production
Histamine acts on…. via…. to increase…
parietal cells via cAMP (H for Happy cAMPer) to increase HCL production
Gastrin produced by…. inhibited by… stimulated by…
antral G cells (why antrectomy helpful); H+ in duodenum, amino acids, Ach
Omeprazole blocks…
H/K ATPase of parietal cells (Every year)
Somatostain inhibits… decreases… stimulated by…
gastrin, insulin, secretin, Ach; pancreatic and biliary output; acid in the duodenem
Proximal vagotomy abolishes…. which increases…
receptive relaxation; liquid emptying, no change fo solids
Truncal vagotomy also increases..
emptying of solids when pyloroplasty done, decreases basal acid by 80%
Most common symptom post vagotomy…
early due to…
late due to…
diarrhea (35%), dumping syndrome in 10%, early due to hyperosmotic load, fluid shift; late due to increased insulin with decreased glucose, very rare dumping unresponsive to diet (Every year)
Enterokinase activates… which then activates..
trypsinogen to trypsin which then activates other enzymes of digestion
CCK: from… three functions…
from intestinal mucosa; 1) contract gallbladder, 2) relax sphincter of Oddi, 3) increase pancreatic enzyme secretion (Every year)
Secretin: primary stimulus of… high flow rate =, low flow rate=
pancreatic bicarb secretion, high flow rate = high bicarb, low Cl. slow flow allows HCO3/Cl exchange so low HCO3, high Cl conc.
Enterglucagon: increased in…. adaption after…
small bowel mucosal hypertrophy, adaption after small bowel resection
Peptide YY: released from…inhibits…
terminal ileum with mixed meal, inhibits acid secretion “ileal brake”
Bile: composition….
Stones from…
80% bile salts, 15% lecithin, 5% cholesterol
Stones from increase chol or decr salts of decr lecithin
Gallbladder concentrates bile by….
active resorption of NaCl, h20 then follow
Bile pool… recirculated every… lose daily…
5g, q4h, 0.5g 10% (Every year)
Primary bile acids:
cholic acid, chenodeoxycholic aicd
Secondary (formed by intestinal bacteria) bile acids:
deoxycholic acid and lithocholic acid
MMC:
interdigestive motility; 90 minute cycles, starts in stomach, goes to TI
MMC Phases: I: II: III: IV:
Phase I quiescence
Phase II gallbladder contraction
Phase III peristalsis
Phase IV subsiding electric activity
Motilin stimulates…
MMC; (Erythromycin is prokinetic by stimulating motilin receptor)
Jejunum absorbs…
most Na and H20 (paracellular), more permeable than ileum
