Here’s a further breakdown of the Gastrointestinal (GI) Tract:
Mouth – This is where mastication takes place to mechanically digest food. There is also a release of saliva to moisten the food and start chemical breakdown of starches.
Bolus (broken down starches) – Chewed food mixed with saliva that is sent down the esophagus.
Esophagus – When food enters the esophagus, stretching of the walls will trigger nerves here that will initiate peristalsis in the gastrointestinal tract.
Stomach – the muscular stomach walls begin to pound your food into chunks. Hormones will trigger release of hydrochloric acid and proteases that will begin to break down protein. Furthermore, hormonal release will also trigger the gallbladder to deliver bile into the next portion of the GI Tract.
Chyme – after a period of about 30mins of mixing and acidification, the resulting material is called chyme and will enter into the small intestine.
Small Intestine – this is the section of the gastroinstestinal tract where the vast majority of chemical digestion occurs. This is where smaller pulverized chyme from the stomach gets broken down into absorbable nutrients.
Duodenum – the liver, via the gallbladder, sends bile here to break down fats. This will help break them down into small sizes that are easier to digest.
Jejunum + Ileum – the second and third portion of the small intestine where food absorption into the bloodstream occurs.
Large Intestine (aka Colon) – dead cells, fiber, and other non digestible food and food waste from the small intestine arrive here. Water is reabsorbed into the body in the colon. This is where our feces begins to form.
Rectum – feces is packed into the rectum from the large intestine, where stretch receptors will send signals to our brain when it is time to evacuate the bowels and defecate.
Anus – the hole that we defecate through and where the process of digestion comes to an end. This process can take anywhere from 30-40 hours in total and is a major investment of energy on the body.