Heartburn results when the acidic contents of the stomach regurtitate into the esophagus

Heartburn is a burning discomfort that is generally felt in the chest just behind the breastbone.  The burning sensation is caused when harsh stomach juices come in contact with and irritate the delicate lining of the esophagus.

Ifound this on google “aristotle (384–322 bc) in western scientific taxonomy the greek philosopher aristotle was the first to classify all living things, and some of his groups are still used today, like the vertebrates and invertebrates, which he called animals with blood and without blood.” i hope this you for what your looking for.