Digestion System

  • Anatomy- Organs that make up the GI tract are the mouth, esophagus, stomach, small intestine and large intestine (which includes the rectum and anus).
  • Physiology- This system is responsible for digestion and processing food.
Digestive Process
Mouth:
  • Food is partly broken down by the process of chewing and salivary enzymes (break down starches) and a bolus is made.
Esophagus
  • After being swallowed, the food enters the esophagus. It uses rhythmic, wave-like muscle movements (called peristalsis) to move food from the throat into the stomach.
Stomach
  • The stomach is a large, sack-like organ that contains a very strong acid (gastric acid). Food in the stomach is partly digested and mixed with a stomach acid, called chyme.
Small Intestine
  • Food enters the duodenum, the first part of the small intestine.
  • It then enters the jejunum.
  • The last stop in the small intestine for food is the ileum.
  • In the small intestine, bile (produced in the liver and stored in the gall bladder), pancreatic enzymes and other digestive enzymes help the breakdown of food.
Large Intestine or Colon
  • Food passes into the large intestine. In the large intestine, some of the water and electrolytes are removed from the food.
  • The first part of the large intestine is called the cecum (the appendix is connected to the cecum).
  • Food then travels upward in the ascending colon.
  • The food travels across the abdomen in the transverse colon.
  • It then goes back down the other side of the body in the descending colon.
  • The last stop for food in the LI is to go through the sigmoid colon.
Rectum
  • Solid waste leaves the colon and is stored in the rectum and excreted via the anus.