to digestive physiology. 2.`Explain the term
alkaline tide a….
1. Explain the term chloride shift as it pertains to digestive physiology.
Chloride shift is a process which occurs in a cardiovascular system and it refers to the exchange of
bicarbonate(HCO3−) and chloride(Cl−) across the membrane of red blood cells. Red blood cells are able to
exchange bicarbonate for chloride using the anion exchanger protein Band 3. Thus, the rise in intracellular
bicarbonate leads to bicarbonate export and chloride intake. The chloride shift may also lead to regulation of
hemoglobin for oxygen through the chloride ion acting as an allosteric effector.
2.`Explain the term alkaline tide as it pertains to digestive physiology.
Alkaline tide refers to a condition which is encountered after eating a meal after which the production of
hydrochloric acid by parietal cells in the stomach, the parietal cells secrete bicarbonate ions across their basolateral
membranes and into the blood, causing a temporary increase in pH. In the event of hydrochloric secretion in the
stomach, gastric parietal cells extract chloride anions carbon(iv)oxide, water and sodium cations from the blood
plasma and in turn release bicarbonate back into the plasma after forming it from carbon dioxide and water
constituents. This maintain plasma electrical balance.
Alkaline tide can be neutralized by a secretion of H+ into the blood during bicarbonate secretion in the pancreas.
References.
Crandall ED, Mathew SJ, Fleischer RS, Winter HI, Bidani A (1981). "Effects of inhibition of RBC HCO3−/Cl− exchange
on CO2 excretion and downstream pH disequilibrium in isolated rat lungs". J. Clin. Invest. 68 (4): 853-62.
doi:10.1172/JCI110340. PMC 370872. PMID 6793631.
Margaret E. Smith; Dion G. Morton (18 November 2011). The Digestive System: Systems of the Body Series. Elsevier
Health Sciences UK. p. 52. ISBN 978-0-7020-4841-8.