Parietal cells: vomit, cavemen and fur trappers
What are they? Large cells in the wall of the stomach that make acid. They sit inside indentations called gastric pits. Here they pump out the strong stomach acid so it mixes with food. The acid is made in response to food in the stomach, but also to seeing food, smelling it and even just thinking about it.
What does stomach acid do? It helps us digest food; anyone who has vomited or had acid reflux will know just how strong it is. So why doesn’t the acid burn away the stomach wall? Because the wall is protected by a layer of mucus made by cells at the top of the gastric pits. What have parietal cells got to do with cavemen? Parietal comes from the Latin word parietalis, which means belonging to the wall’’. Paintings made by cavemen on the sides of cave walls are called parietal art.
And a fur trapper?
‘‘ The realisation that stomach juice contains acid that helps digestion in part came from nine years of experiments in the US on a fur trapper called Alexis St Martin. In 1822, St Martin was accidentally shot in stomach, leaving a hole through which food splilled out of his side.
Remarkably, he survived, but still with the hole in his side.
This allowed his doctor — William Beaumont— to experiment, for example by dangling food on a string into St Martin’s stomach and then pulling it out to see what had happened to it. St Martin lived until he was 83.