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Chapter 30: Nutrition and Digestion At a Glance

Case Study: Fat in the Family?

30.1 What Nutrients Do Animals Need?

• Cells Continuously Expend Energy, Which Is Derived from Nutrients and Measured in Calories
• Lipids Include Fats, Phospholipids, and Cholesterol
  Animals Store Energy as Fat
• Carbohydrates, Including Sugars and Starches, Are a Source of Quick Energy
• Proteins, Composed of Amino Acids, Perform a Wide Range of Functions Within the Body
• Minerals Are Elements Required by the Body
• Vitamins Are Required in Small Amounts and Play Many Roles in Metabolism
  Water-Soluble Vitamins
  Fat-Soluble Vitamins
• Nutritional Guidelines Help People Obtain a Balanced Diet

30.2 How Is Digestion Accomplished?

• An Overview of Digestion

Health Watch: Eating Disorders—Betrayal of the Body

• Digestion Within Single Cells Occurs in the Sponges
• A Sac with One Opening Forms the Simplest Digestive System
• Digestion in a Tube Allows Animals to Feed More Frequently
• Digestive Specializations
  Special Adaptations Allow Ruminants to Digest Cellulose
  Intestinal Length Is Correlated with Diet
  Teeth Evolved to Accommodate Different Diets
  Birds Have Gizzards for Grinding Food

30.3 How Do Humans Digest Food?

• The Mechanical and Chemical Breakdown of Food Begins in the Mouth

Health Watch: Ulcers: Digesting the Digestive Tract

• The Esophagus Conducts Food to the Stomach
• Most Digestion Occurs in the Small Intestine
  The Liver and Gallbladder Provide Bile, Important in Fat Breakdown
  The Pancreas Supplies Several Digestive Secretions to the Small Intestine
  The Digestive Process Is Completed by Cells of the Intestinal Wall
• Most Absorption Occurs in the Small Intestine
• Water Is Absorbed and Feces Are Formed in the Large Intestine
• Digestion Is Controlled by the Nervous System and Hormones

Case Study Revisited: Fat in the Family?

Links to Life: Are You Too Heavy?