SUMMARY

GUT ANATOMY AND PHYSIOLOGY

From start to finish, your alimentary canal consists of your mouth, esophagus, stomach, small intestine (duodenum, jejunum, ileum), and large intestine (colon, rectum, anus).

Other important digestive organs include your salivary glands, pancreas, gallbladder, and liver.

Sphincters act as your gut’s security gates, regulating the flow of boluses, chyme, and stool from one section to another.

Your esophagus serves primarily as a transport tube between your mouth and stomach.

Your stomach relies on mechanical (churning and peristalsis) and chemical (release of hydrochloric acid and enzymes) processes to digest macronutrients, particularly protein.

Your pyloric sphincter regulates the flow of nutrients into your small intestine by opening and closing, a process that’s influenced by the specific nutrients coming into contact with sensory tissue in your duodenum.

Your small intestine is the main site of absorption in your gut, thanks to circular folds, small fingerlike projections called villi, and tiny hairlike structures known as microvilli, which create a massive surface area.

Your large intestine is responsible for absorbing water and electrolytes that escape your small intestine, resulting in the formation of stool.

Your large intestine is home to trillions of microorganisms that affect your gut’s function and your health, in part via the metabolism of fiber and other poorly absorbed carbohydrates.

Your gut is home to your second brain, a network of 100 million to 600 million neurons that is integral to your gut’s functions and which plays a role in regulating your mood.