Hydrochloric AcidPneumonia, AspirationNitric AcidGastric JuiceDecalcification TechniqueTrifluoroacetic AcidCountercurrent DistributionEsophagusHydrogen-Ion ConcentrationStomachAcidsFluoroacetatesAchlorhydriaParietal Cells, GastricGastric AcidSulfuric AcidsGastric FistulaGastric MucosaSodium HydroxideAlkalosisPentagastrinPepsin AAppendixAcidosisDuodenumSodium ChlorideSpectrophotometry, AtomicSecretinStomach UlcerBicarbonates