Module 7 Intro

Module 7—The Digestive and Respiratory Systems

Explore

Before you begin this lesson, you may find it useful to look over a list of vocabulary and definitions that you will be required to know as you work through this lesson. You can print off or save the following vocabulary chart to your course folder.

The chart is incomplete and requires you to fill in a definition or a corresponding vocabulary word. The chart is long, but you likely are already familiar with some of the words on the list. As you encounter unfamiliar words, refer to this chart to record definitions and words as a tool to help you organize what happens in the digestive system.

Structures of the Digestive System

How much thought or planning do you put into what you will be eating for breakfast, lunch, and supper? Nutritious meals take a great deal of planning to provide the optimal quantities of nutrients, vitamins, and minerals necessary to keep people’s bodies at the peak of health.

Despite the effort involved in preparing food, there is little conscious thought once the food begins its journey through the gastrointestinal tract. People really only think about two stages—the decision to swallow the masticated bolus (chewed food ball) and the purposeful decision to eliminate the fecal material after processing the food.

Everything in between is part of a complex and automatic response. It ensures that the food taken in ends up being converted to either usable molecules, which are absorbed, or to unusable waste products, which are eliminated.

You can find many animations and videos on the Internet that will show you the path of food through your digestive system. Perform the following two web searches:

• keywords: tv demonstrating biology demonstrations

• keywords: how stuff works digestive system

The first web search could result in a video that explains demonstrations to use in the classroom. The first demonstration in the video may show how you can simulate the path of food through the body.

Perhaps the second animation traces the pathway of food as it passes from the mouth to the anus. Pay particular attention to the structures that make up the pathway and their location. If this information is available, note the discussion of the breakdown of the milk sugar lactose, and check the repercussions of not being able to break down this sugar.

The diagram on page 217 of your text outlines all of the structures of the digestive system.

Self-Check

SC 1. Do the following Self-Check activity about structures of the digestive system.