3.43 Stomach Facts
The stomach is the body organ where the food goes and gets digested. Discover facts about the stomach and learn about the main jobs and functions of the stomach.
What Is the Stomach?
If someone asked you to point to your stomach, where would you point? Many people think their stomach is in the area by their belly button, which is located in the abdomen (the area of the body between the ribs and hips), but your stomach actually higher up in your abdomen. Your stomach is in the top of your abdomen on the left side of your body.
| The stomach is in the top part of your abdomen on the left side of your body. |
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Shaped like the letter J, your stomach is mostly an empty sack. Even though some people’s abdomens look larger than others, everyone’s stomach is about the same size: 12 inches long and 6 inches wide.
What Does the Stomach Do?
The stomach’s main jobs are to store and break down the food you eat. Let’s explore these two functions in more detail.
1. Main points:
The stomach, located in the upper left side of the abdomen, is a J-shaped empty sack about 12 inches long and 6 inches wide, primarily responsible for storing and breaking down food.
2. Questions:
- Content Analysis: Where is the stomach located in the human body, and what is its shape and size?
- Contextual Analysis: What are the primary functions of the stomach?
- Linguistic Analysis: What words in the text describe the location and role of the stomach?
3. Further Discussion:
Why is the stomach’s position and shape important for its function in digestion?
4. Answers:
- Content Analysis: "Your stomach is in the top of your abdomen on the left side of your body… Shaped like the letter J… about the same size: 12 inches long and 6 inches wide."
- Contextual Analysis: "The stomach’s main jobs are to store and break down the food you eat."
- Linguistic Analysis: Words like "top of your abdomen," "left side," "J-shaped," "empty sack," "store," and "break down" describe the location and role of the stomach.
Storing Food
Just like your backpack is flat when empty and stretches to hold your books, your stomach stretches to hold all the food you eat. Food can be stored in your stomach for up to five hours, but it usually only takes about three hours for your stomach to digest and pass it on to the intestines.
Think about the last time you ate a large meal. Did your stomach feel really big? That is because it stretched to hold all that food. In fact, your stomach is so stretchy that it can expand to hold over a gallon of food!
Digesting Food
Have you ever heard your tummy rumble or growl when you’re hungry? The noise is cause by your stomach muscles contracting and pushing the walls of your stomach together. These muscles, which are very strong, are also what line the stretchy walls of your stomach and help you digest food. They help the stomach churn, or move back and forth. When your stomach moves, it mixes and mashes the food inside, causing it to break into small pieces.
The cells in the walls of your stomach also make a liquid called gastric juice. This special kind of juice isn’t like the juice you drink at lunch–it’s a strong acid that helps break down the food in your stomach into even smaller pieces. Your gastric juices also protect your body from germs by killing bacteria and other harmful things that may be on the food you eat.
| The walls of your stomach make gastric juice, a strong acid that helps break down the food you eat. |
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Food broken down into tiny pieces and mixed with gastric juice in the stomach is called chyme. After it’s made in the stomach, chyme moves into the intestines to be digested further.
An interesting fact: your stomach not only stores and starts to digest your food, but it also knows when you’re embarrassed. When you blush and your cheeks turn red, your stomach lining also turns red!
1. Main points:
The stomach stretches to store food, which it can hold for up to five hours, and aids in digestion by churning food and producing gastric juice, a strong acid. The resulting mixture, chyme, then moves to the intestines for further digestion. Additionally, the stomach lining reacts to emotions like embarrassment.
2. Questions:
- Content Analysis: How does the stomach store and digest food?
- Contextual Analysis: What role does gastric juice play in the digestion process?
- Linguistic Analysis: What words in the text describe the stretching and churning action of the stomach?
3. Further Discussion:
Why is it important for the stomach to be able to stretch and contract?
4. Answers:
- Content Analysis: "Your stomach stretches to hold all the food you eat… The stomach churns, or moves back and forth… mixes and mashes the food."
- Contextual Analysis: "Gastric juice… is a strong acid that helps break down the food in your stomach into even smaller pieces."
- Linguistic Analysis: Words like "stretches," "churn," "mixes," "mashes," and "strong acid" describe the stretching and churning action of the stomach.
Lesson Summary
Your stomach is located in the upper left part of your abdomen. The stomach’s main jobs are to store and break down food. The stomach churns and makes gastric juice to help digest the food we eat and protect us from germs. Food that has been broken down in the stomach is called chyme.
Additional Activities
Discussion Questions Regarding Stomach Anatomy and Functions
Consider the following functions of the stomach and discuss the features which help the stomach achieve those functions.
Storage of Food.
The lesson discussed that one of the functions of the stomach is to store food. The stomach has the ability to expand and accommodate the food which is eaten, while it is being digested. in order to store and digest food, the stomach needs to keep the food in the stomach, without passing immediately into the small intestines or back into the esophagus. Research the anatomy of the stomach and discuss the features at each end of the stomach which keep food contained in the stomach.
Digesting Food
The lesson also described the digestion function of the stomach. Churning of the stomach helps to mix the food and break it down into smaller pieces. Research the layers of the stomach wall. How does the anatomy of the stomach wall function to mix and break up the food?
Answers
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Storage of Food – The stomach has two valves to contain food within the stomach. The valve at the entrance is called the cardiac sphincter. This valve functions to keep food from going back to the esophagus. The valve at the exit to the stomach is called the pyloric sphincter. This valve regulates food being released into the small intestines.
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Digesting Food – The wall of the stomach has a layer called the muscularis. This contains three layers of muscle fibers at different orientations to each other, allowing the churning action of the stomach.