Lesson 6: The Digestive System (page 3 of 8)

True, the digestion of proteins, which occurs primarily in the stomach, requires a very acid environment, provided in the stomach by HCL (hydrochloric acid.)

The first portion of the small intestine is the duodenum. Bile, produced in the liver and stored in the gall bladder, is secreted into the duodenun by contractions of the gall bladder. The primary function of the bile is the emulsification of fats. Emulsification is the process whereby large globules of fat are broken down into smaller globules and made water soluble. One of the primary ingredients in the bile is cholesterol.

The Liver and Pancreas
At the same time that bile is secreted by the gall bladder, pancreatic juices are secreted by the pancreas into the duodenum. The bile and pancreatic juices change the pH from acid back to basic. This higher pH is necessary for the action of the pancreatic enzymes, which continue the digestive process by breaking down carbohydrates and fats into tiny particles that can be absorbed in the intestines.


The substance secreted by the liver and stored in the gall bladder and released into the small intestines for the emulsification of fats is _____________.

 Protease
 Bile
 Lipase
 HCL

(Select the best answer and click on the “Continue” button.)