Gastric acid

In humans, the pH is between one and three, much lower than most other animals, but is very similar to that of carrion eating carnivores, needing protection from ingesting pathogens.

Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring a regulated pH.

These cells also produce mucus – a viscous barrier to prevent gastric acid from damaging the stomach.

The pancreas further produces large amounts of bicarbonate, secreting this through the pancreatic duct to the duodenum to neutralize gastric acid passing into the digestive tract.

Parietal cells contain an extensive secretory network (called canaliculi) from which the hydrochloric acid is secreted into the lumen of the stomach.

[2] The parietal cell releases bicarbonate into the bloodstream in the process, which causes a temporary rise of pH in the blood, known as an alkaline tide.

[5] In humans, the pH of gastric acid is between one and three, much lower than most other animals, but is very similar to that of carrion eating carnivores, needing extra protection from ingesting pathogens.

Chloride and hydrogen ions are secreted separately from the cytoplasm of parietal cells and mixed in the canaliculi.

Beside this, the endings of the vagus nerve (CN X) and the intramural nervous plexus in the digestive tract influence the secretion significantly.

The release of histamine is the most important positive regulation mechanism of the secretion of gastric acid in the stomach.

Most people are able to manage the discomfort of GERD with lifestyle changes and medications, notably proton pump inhibitors, and H2 blockers.

[citation needed] In diseases featuring excess vomiting, hypochloremic metabolic alkalosis (decreased blood acidity by H+ and chlorine depletion) may develop.