About this chapter
Digestive System - Chapter Summary and Learning Objectives
The human digestive system is a complex system made up of various organs, each of which have their own distinct function in the process of breaking down and using food. Without a properly working digestive system, your body will fail. If even one part of the process isn't working correctly or if one organ is not doing its job, you could, at the very least, become very sick. Understanding the digestive system is the focus of this chapter. You'll watch lessons relating to the various parts of the system and their functions. Some of the things you will learn include:
- The anatomy of the mouth
- Nervous system controls of the stomach
- The role of gastric juices
- The functions of the small intestine
- Organs that assist the digestive system
- Lipids and proteins in the digestive process
|Anatomy and Physiology of the Mouth||Study the different parts and functions of the mouth, such as the salivary response, salivary glands, bolus, pharynx and esophagus.|
|Anatomy of the Throat and Esophagus||Discover the divisions of the pharynx.|
|Anatomy and Physiology of the Stomach and Autonomic Nervous System Controls||Explore the stomach to discover things like the gastric glands, pylorus and sphincter.|
|Physiology of the Stomach and Gastric Juices||Examine the gastric juices and other physiology of the stomach, including hydrochloric acid, chief cells, pepsin and peptic ulcers.|
|Small Intestine: Anatomy and Functions||Analyze the small intestine, including the duodenum, ileum, jejunum, villa and pendular movement.|
|Accessory Digestive Organs: Pancreas, Gallbladder & Liver||Study the pancreas, gallbladder and the liver, including exocrine secretions, bicarbonate, digestive enzymes, secretin and bile.|
|Carbohydrate Digestion and Absorption: Process & End Products||Learn more about the process of carbohydrate digestion and absorption.|
|Protein Digestion and Absorption Process||Discover the process of protein digestion and absorption.|
|Lipids Digestion and Absorption||Examine lipids in the digestive system to learn about things like bile salts, emulsification and lacteals.|
|Large Intestine and Rectum: Anatomy, Functions & Water Absorption||Explore the jobs of the large intestine and rectum to learn about the colon, rectum, anus and reabsorption of water.|
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.