Fluid and Electrolytes Flashcards
What is the target of the C.diff toxin A and B?
Cytoskeleton disruption
What is absorbed and secreted in the large intestines?
HCO3 and K are secreted
Na, Cl, and H2O are absorbed
How is Na absorbed in the intestines? (3)
SLGT1, amino acid B transporters, and Na?h exchanger during the fed state with paired Na/K pump on the basolateral side
What ion always goes with HCO3?
Cl–always in opposite directions
What causes Cl absorption?
Na absorbed, so Cl pulled along, as well as a HCO3/Cl exchanger
What is the protein that regulates Cl/water secretion? What ion (not Cl) is needed for it to function?
CFTR (cystic fibrosis transport regulator)–need Ca, cAMP
How is K secreted from the large intestines?
Net negative lumen of the intestines, as well as Na/K pump
How is K reabsorbed in the small intestines?
Follows water back in the intestines between the cells
What is the function of increased cAMP, cGMP, and Ca in the intestinal lumen? (2) What is the net effect of this?
Inhibits Na/H pump, increases Cl channel
Thus Na remains in the lumen, and Cl is secreted into the lumen
Somatostatin always has what effect on the GI system (inhibitory or excitatory)?
generally inhibitory, but promotes fluid absorption
What are the four causes of diarrhea?
- Increased intestinal secretion
- Decreased intestinal absorption
- Increased osmotic load
- Abnormal intestinal motility
What is osmotic diarrhea?
Diarrhea caused by a nonabsorbable nutrient
What is secretory diarrhea?
Diarrhea caused by intestinal secretion of fluid and electrolytes
Osmotic, secretory, or both: disaccharidase deficiency?
Osmotic
Osmotic, secretory, or both: enterotoxins?
Secretory
Osmotic, secretory, or both: inflammatory cytokines
Both
Osmotic, secretory, or both: pancreatic enzyme deficiency
Osmotic
Osmotic, secretory, or both: Nutrient-binding substances
Osmotic
Osmotic, secretory, or both: tumor (VIP, 5HT secretion)?
Secretory
Osmotic, secretory, or both: infectious disease?
Both