Chapter 16, Section 2 The Digestive Process Begins Wednesday, March 3, 2010 Pages

Objectives Describe the general functions carried out by the digestive system. Describe the specific functions of the mouth, esophagus, and stomach.

Vocabulary Words Digestion Absorption Saliva Enzyme Epiglottis Esophagus Mucus Peristalsis Stomach

Digestive System Functions Breaks down food into molecules the body can use (Digestion). Molecules are absorbed into the blood and carried throughout the body (Absorption). Wastes are eliminated from the body (Elimination).

The Mouth Digestion begins in the mouth –Teeth cut and tear food into smaller pieces. –Saliva plays an important role in the mechanical and chemical digestive process.

Mechanical Digestion Begins with the first bite of food. Your teeth begins the process by grinding and cutting your food into smaller pieces. Saliva mixes with the food and moistens them to make swallowing easier.

Chemical Digestion Chemical digestion also begins in the mouth. It is the breakdown of complex molecules into simpler ones. This process is aided by enzymes.

The Esophagus When you swallow, muscles in your throat move the food downward. The epiglottis seals off your windpipe to prevent food from entering. Food enters the esophagus - a muscular tube that connects the mouth to the stomach. –Esophagus lined with mucus

The Stomach J-shaped organ. –Muscular pouch located in the abdomen. –Expandable to hold about 2 liters of food. –Chemical and mechanical digestion happens here. Food is further broken down by digestive juices. –Lined with mucus which coats and protects the lining of the stomach.

Homework Workbook 16.2 (3/5) Vocabulary quiz 16.2 (3/5)