What does a hyphen look like? â is a punctuation mark used to join words and to separate syllables of a single word.
Definition of gastrointestinal tract. medical. : the part of the digestive system that consists of the stomach and intestines.
The gastrointestinal (GI) tract is formed, with a few exceptions, by four concentric layers of tissue. These are, from deep to superficial, the mucosa, submucosa, muscular (or muscularis) and the serosa layers.