A Look Inside Your Digestive System

The Mouth

Digestion begins in your mouth. Your teeth grind the food you eat and mix it with saliva to form a kind of ball, known as a bolus.

During the mixing, an enzyme called salivary amylase starts breaking down carbohydrates. Once the food is soft and relatively flexible, the tongue pushes it to the back of your mouth and into the esophagus.

The Esophagus

Your esophagus is a flattened muscular tube that connects your mouth to your stomach. As food is swallowed, your esophagus expands. It takes food about three seconds to pass through your esophagus, depending on the texture and consistency.

The Stomach

Your stomach is a J-shaped muscular pouch, which receives food from your esophagus and sends it to your small intestine. Inside your stomach, food is mixed with enzymes and acid until it becomes a liquid, called chyme.

The stomach is the main site for protein digestion and uses powerful enzymes, known as pepsins, as well as hydrochloric acid, to digest foods like meats, milk, and cheese.

The Small Intestine

The small intestine is an approximately 20-foot-long muscular tube, which is divided into three distinct parts: the duodenum, the jejunum, and the ileum. Each of the three parts plays a major role in digestion and absorption.

Absorption is a crucial part of the digestive process that brings the molecules from the digested food into the blood and, ultimately, the cells.

The Large Intestine

The last part of the digestive tract, the large intestine, is a muscular tube that is about 6 feet long. It's divided into the cecum, the colon, and the rectum. Together, these segments complete any nutrient absorption and process the waste into feces.

Problems with your large intestine can be caused by diseases such as inflammatory bowel diseases (IBD) like Crohn's disease and ulcerative colitis as well as celiac disease. If parts of these organs become seriously diseased, they may require surgical removal. When this happens, an ostomy may be necessary to aid digestion and elimination.

The Anus

The anus is the last organ of the digestive system. It is a 2-inch long canal consisting of pelvic floor muscles and two anal sphincters (internal and external) which allow you to hold in feces until you are able to get to a bathroom to release the contents into the toilet.

The Pancreas

The pancreas is one of the three "accessory" digestion-related organs. Your pancreas assists your small intestine by secreting pancreatic juice, a liquid filled with enzymes and sodium bicarbonate that is able to stop the digestion process of pepsin. It also secretes insulin, which helps your body regulate your blood sugar.

The Liver

Your liver has many functions. First, it produces bile, which the small intestine uses to help digest the fats in food.

It also metabolizes proteins, carbohydrates, and fats; helps regulate blood sugar levels; stores glycogen for quick energy; makes fibrinogen, which clots blood; makes vitamin A; and recycles worn-out red blood cells.

The Gallbladder

Tucked under the liver, your gallbladder is a storage container for bile, a yellow-green fluid made up of salts, cholesterol, and lecithin. Your small intestine uses bile to digest fats.

Most people never think about their gallbladder until a problem with gallstones or gallbladder disease, such as cholecystitis, develops. If you have a gallbladder-related disease, you may experience jaundice.

This happens when the bile cannot leave the gallbladder. Instead, the bile enters the bloodstream, which can cause your skin, eyes, and nails to appear yellow.