The liver (located under the ribcage in the right upper part of the abdomen), the gallbladder (hidden just below the liver), and the pancreas (beneath the stomach) are not part of the digestive canal, but these organs are essential to digestion.
The Pancreas
Enzymes produced by the pancreas are secreted into the small intestine to further break down food after it has left the stomach. After food enters the duodenum, the exocrine secrete a clear, watery, alkaline juice that contains several enzymes that break down food into small molecules that can be absorbed by the intestines:
- Trypsin to digest proteins
- Amylase to break down carbohydrates
- Lipase, to break down fats into fatty acids and cholesterol.
The Liver
The liver plays a role in the process of digestion through the production of bile. Bile is a mixture of water, bile salts, cholesterol, and the pigment bilirubin. Hepatocytes in the liver produce bile, which then passes through the bile ducts to be stored in the gallbladder. When food containing fats reaches the duodenum, the cells of the duodenum release cholecystokinin to tell the gallbladder to release bile. Bile travels through the bile ducts and is released into the duodenum where it surrounds large masses of fat. The emulsification of fats by bile turns the large clumps of fat into smaller pieces that have more surface area and are easier for the body to digest.
The Gall Bladder
The gallbladder can be thought of as a storage sac that helps the liver. It is defined as a small sac-shaped organ that stores and concentrates bile. Your gallbladder lies beneath your liver. When there is no food in the small intestine, bile - that was initially made by the liver - backs up into the gallbladder to be stored.