14.1 The Digestive Tract

• The human digestive system is an extended tube with specialized parts between two openings, the mouth and the anus.
• Food is ingested and then digested to small molecules that are absorbed. Indigestible materials are eliminated.

1. What stimulates the gallbladder to release bile to the small intestine?
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2. What are some of the ways the small intestine is adapted for increased absorption?
   Answer
   
   

Essential Study Partner
    Introduction
    Human Digestion
    Histology
    Mouth and Esophagus
    Stomach
    Small Intestine
    Large Intestine

Art Quizzes
    Specialization of Digestive Tract
    Stomach and Duodenum
    Stomach Mucosa – Gastric Glands
    Action of Gastrin
    Digestive System Variations (1)
    Digestive System Variations (2)

Animation Quizzes
    Digestion
    Digestion Mouth to Stomach
    Digestion Stomach
    Stomach Digestion
    Digestion Stomach to Small Intestine
    Small Intestine Digestion
    Endoscopy
    Ulcers

General Biology Weblinks
    Anatomy & Physiology

Labeling Exercises
Digestive System (1) (30.0K)
Digestive System (2) (43.0K)
Digestive System (3) (46.0K)
Mouth (41.0K)
Teeth (47.0K)
Swallowing (49.0K)
Wall of the Digestive Tract (32.0K)
Anatomy of Small Intestine (46.0K)

14.2 Three Accessory Organs

• The pancreas, the liver, and the gallbladder are accessory organs of digestion because their activities assist the digestive process.

1. How does the pancreas assist digestion?
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2. How does the liver act as "gatekeeper" to the blood?
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Essential Study Partner
    Accessory Organs
    Liver & Pancreas

Art Quizzes
    Actions of Insulin and Glucagon

Animation Quizzes
    Formation of Gallstones

Labeling Exercise
Hepatic Lobules (47.0K)

14.3 Digestive Enzymes

• The products of digestion are small molecules, such as amino acids, fatty acids, and glucose, that can cross plasma membranes.
• The digestive enzymes are specific and have an optimum temperature and pH at which they function.

1. Where does the digestion of carbohydrates begin in the body?
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2. Why is hydrochloric acid needed for digestion to occur in the stomach?
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Essential Study Partner
    Enzymes and Hormones

Art Quizzes
    Absorption of Protein and Carbohydrate
    Absorption of Fats

14.4 Nutrition

• Proper nutrition supplies the body with energy, nutrients, and all vitamins and minerals.

1. Why are whole grains a healthier dietary choice than refined and milled flours?
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2. What is the main difference between the modern diet of native Hawaiians compared with the ancient diet of the same people?
   Answer
   
   

Essential Study Partner
    Nutrition
    Carbohydrates
    Lipids
    Proteins
    Vitamins & Minerals
    Food Needs
    Food Production
    Food Quality

Case Studies
    Power Lunch of the Future
    Bulimia