When you see (or smell) something appetizing, your digestive organs leap into action. Your mouth waters. Your stomach contracts. Intestinal glands begin to secrete the chemicals that turn food into the nutrients that build new tissues and provide the energy you need to keep zipping through the days, months, and years.
This chapter introduces you to your digestive system and explains exactly how your body digests the many different kinds of foods you eat, all the while extracting the nutrients you need to keep on truckin’. Your digestive system may never win a Tony, Oscar, or Emmy, but it certainly deserves your applause for its ability to turn complex food into basic nutrients. Doing this requires not a cast of thousands but a group of digestive organs, each designed specifically to perform one role in the two-part process. Read on.
The digestive organs
Although exceedingly well-organized, your digestive system is basically one long tube that starts at your mouth, continues down through your throat to your stomach, and then goes on to your small and large intestines and past the rectum to end at your anus.
In between, with the help of the liver, pancreas, and gallbladder, the usable (digestible) parts of everything that you eat are converted to simple compounds that your body can easily absorb to burn for energy or to build new tissue. The indigestible residue is bundled off and eliminated as waste.
Digestion: A two-part process
Digestion is a two-part process — half mechanical, half chemical:
This chapter introduces you to your digestive system and explains exactly how your body digests the many different kinds of foods you eat, all the while extracting the nutrients you need to keep on truckin’. Your digestive system may never win a Tony, Oscar, or Emmy, but it certainly deserves your applause for its ability to turn complex food into basic nutrients. Doing this requires not a cast of thousands but a group of digestive organs, each designed specifically to perform one role in the two-part process. Read on.
The digestive organs
Although exceedingly well-organized, your digestive system is basically one long tube that starts at your mouth, continues down through your throat to your stomach, and then goes on to your small and large intestines and past the rectum to end at your anus.
In between, with the help of the liver, pancreas, and gallbladder, the usable (digestible) parts of everything that you eat are converted to simple compounds that your body can easily absorb to burn for energy or to build new tissue. The indigestible residue is bundled off and eliminated as waste.
Digestion: A two-part process
Digestion is a two-part process — half mechanical, half chemical:
- Mechanical digestion takes place in your mouth and your stomach. Your teeth break food into small pieces that you can swallow without choking. In your stomach, a churning action continues to break food into smaller particles.
- Chemical digestion occurs at every point in the digestive tract where enzymes and other substances, such as hydrochloric acid (from stomach glands) and bile (from the liver), dissolve food, releasing the nutrients inside.
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