Digestive System How do we break down food into energy?
Definition • the process by which food and drink are broken down into its smallest parts so the body can use it to build new cells, nourish the body, and provide energy.
How does food travel? • Digestion begins in the mouth when food is chewed and is completed in the small intestine. • 3 Parts: mechanical digestion, chemical digestion, and absorption.
Mechanical Digestion • When food is physically broken into smaller pieces by chewing in the mouth or churning in the stomach.
Chemical Digestion • caused by digestive juices such as stomach acid, and enzymes produced by glands.
Absorption • Absorption occurs in the small intestine for food and the large intestine for water for distribution to the rest of the body.
Labeling the Digestive System Organs • Use your book to look at page 483 • Use this page to help label the organs of the digestive system.
Let’s Journey Through the Digestive System • As food enters your mouth, you begin to chew it up and then swallow. • When you swallow, it begins to go down through your esophagus. Your esophagus is the long tube in your neck that attaches your throat to your stomach. • As food travels down your esophagus, it begins the journey into the digestive system and lands in the stomach.
Stomach • It is a J shaped organ that stores food and helps digest it • The stomach acids help break the food down more before entering the small intestine.
Liver • It is a large organ that produces bile. • Bile is green acid that breaks down food during digestion. • Once bile is made in the liver, it moves to the stomach to help in digestion.
Pancreas • produces several important hormones, including insulin, as well as an exocrine gland, secreting pancreatic juice containing digestive enzymes that pass to the small intestine. • These juices help break down carbohydrates, protein, and fat.
Intestines • Small intestine- long, coiled tube where food is digested and absorbed • Villi are the finger-like substances covering the inner wall that help move the food • Large intestine- short, wide tube where water is absorbed from undigested food • Food travels through the intestine through a series of peristalsis- squeezing motion that pushes food through the digestive system
Rectum • Stores solid waste until it leaves the body • Located at the end of the large intestine
Anus • The opening through which solid waste leaves the body
Chew on This • On your own and using your notes, match the organ to the definition and then find the magic number.