About This Chapter
Functions of the Human Digestive System - Chapter Summary
In this chapter, you'll complete a thorough overview of the digestive organs, fluids and processes. You can explore how food is broken down, absorbed and eliminated. Each lesson presents important term definitions and examples to help clarify the material being discussed. Once you have completed your review of this chapter, you should be able to do the following:
- Relate the physiology of the mouth, throat, esophagus and stomach
- Describe the anatomy of the small and large intestines
- Discuss facts about gastric juices and pancreatic, liver and gallbladder functions
- Define terms relevant to the small intestine, such as peristalsis and pendular movement
- Detail how nutrients are absorbed in the small intestine
- Understand the process of carbohydrate digestion and absorption
- Explain the processes by which lipids and proteins are digested and absorbed
Our experienced science instructors deliver each lesson using simple language and detailed examples and illustrations to make sure you easily develop a full understanding of these topics. You can check what you know or have learned by taking self-assessment quizzes with each lesson. Access the videos on any device, at any time, and track your progress on your Dashboard as you move through this chapter.
1. Anatomy and Physiology of the Mouth
The digestive system is a long tube that breaks food down both mechanically and chemically. In this lesson, you will learn about the mouth and how it begins the digestive process - with the help of the teeth and the enzyme called salivary amylase.
2. Anatomy of the Throat and Esophagus
After food has been partially broken down in the mouth, it moves through the pharynx, or throat, and the esophagus. In this lesson, you will learn how food is swallowed and how it is propelled by peristalsis through the esophagus.
3. Anatomy and Physiology of the Stomach and Autonomic Nervous System Controls
In this lesson, you will learn how the unique anatomy of the stomach - including rugae, gastric pits and gastric glands - makes it a perfect organ for digestion. You will also learn how the autonomic nervous system controls digestion.
4. Physiology of the Stomach and Gastric Juices
When food enters your stomach, it is mechanically broken down by a process called churning. In this lesson you will learn about this process and the chemical break down of proteins within the stomach by the enzyme pepsin.
5. What is the Small Intestine? - Anatomy and Functions
In this lesson, you will learn about the three divisions of the small intestine - the duodenum, jejunum, and ileum. You will also gain an understanding of the basic functions of each of these sections, including their role in removing bacteria.
6. What Is the Pancreas? - Function, Enzymes & Role in Digestion
Your pancreas plays an important role in the digestion of food. In this lesson, you will learn about the enzymes found in pancreatic juice that allow your body to break down carbohydrates, proteins and fats.
7. The Gallbladder & Liver: Function & Role in Digestion
Bile is produced by the liver and stored in the gallbladder. In this lesson, you will learn about bile and its role in the breakdown of dietary fats. You will also learn how the hormones secretin and cholecystokinin help regulate these organs.
8. Movement Through the Small Intestine: Peristalsis, Segmentation & Pendular Movement
The small intestine is an important organ for digestion and absorption of nutrients. In this lesson, you will learn about the enterogastric reflex. You will also learn how intestinal movements, such as peristalsis, segmentation, and pendular movement, improve digestion and absorption.
9. Small Intestine: Nutrient Absorption and Role In Digestion
The majority of digestion and absorption of nutrients takes place in the small intestine. In this lesson, you will learn about unique modifications within the walls of the small intestine, such as microvilli, villi, and circular folds. These structures increase absorption of nutrients.
10. Anatomy and Physiology of the Large Intestine
The large intestine is the made up of the cecum, colon, rectum and anal canal. In this lesson, you will learn about the anatomical features and basic functions of these large intestine segments.
11. Rectum, Functions of the Large Intestine & Water Absorption
The large intestine is the final processing area for digested food. In this lesson, you will learn how the large intestine removes water from undigested food and prepares for the elimination of feces through the anus.
12. Chemical Digestion of Carbohydrates: Definition & Process
Carbohydrates are an important energy source, but must be broken down to be absorbed out of the digestive tract. In this lesson, you will learn how disaccharides and polysaccharides are broken down to monosaccharides through a process called hydrolysis.
13. Carbohydrate Digestion and Absorption: Process & End Products
Carbohydrates that you eat are broken down to monosaccharides by enzymes in your digestive tract. In this lesson, you will learn about these digestive enzymes and how monosaccharides are absorbed out of the digestive tract.
14. Protein Digestion and Absorption Process
Protein is one of the primary nutrients your body uses to build cellular structures. In this lesson, you will learn how protein is broken down into amino acids within your digestive tract and how amino acids are absorbed out of the intestines and into the hepatic portal system.
15. Lipids Digestion and Absorption
Lipids, or fats, are digested and absorbed in the small intestine. In this lesson, you will learn how bile salts emulsify fat so pancreatic lipase can digest it. You will also learn how fats first enter lymphatic capillaries, called lacteals, before entering your blood circulation.
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