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The Digestive System: A fun engaging overview of what happens when we eat will teach you everything you need to know about your body's digestive system.
Lots happens when you eat so come with us as we learn all about it! You may have recently eaten breakfast or lunch, and had a productive morning in class, or enjoyed recess. Now, you’re either at home reading this or in the classroom.
But the inside of your body is hard at work taking all the food you have eaten and turning it into nutrients and energy. It is the digestive system of your body responsible for breaking down the food you eat. The process of food being broken down is called digestion. Digestion allows the body to receive the nutrients and the energy from the food you eat. During digestion, all of the food you eat is eventually turned into the building blocks and fuel you need to live life each day.
The Digestive System
The Digestive System
The digestive system consists of the parts of the body that work together to turn food and liquids into the building blocks and fuel that the body needs.
What Is the Digestive System?
The digestive system breaks down the food we eat into tiny parts to give us fuel and the nutrients we need to live. As food breaks down, we get amino acids from protein, simple sugars from starches, and fatty acids and glycerol from fats.
What Are the Parts of the Digestive System?
The digestive system is made up of:
the alimentary canal (also called the digestive tract). This long tube of organs makes a pathway for food to travel through the body. It runs from the mouth to the anus (where poop comes out) and includes the esophagus, stomach, and intestines. An adult's digestive tract is about 30 feet (about 9 meters) long.
other organs that help the process by adding enzymes and chemicals to break down the food. Important organs that help with digestion include the salivary glands, liver, gallbladder, and pancreas.
Why is digestion important?
Digestion is important because your body needs nutrients from the food you eat and the liquids you drink in order to stay healthy and function properly. Nutrients include carbohydrates, proteins, fats, vitamins, minerals and water. Your digestive system breaks down and absorbs nutrients from the food and liquids you consume to use for important things like energy, growth and repairing cells.
The mouth:
Digestion begins even before we taste food. When we see, smell, taste, or even imagine a tasty meal, our salivary glands (located in front of the ears, under the tongue, and near the lower jaw) begin making saliva (spit).
Teeth tear and chop the food. Spit moistens it for easy swallowing. A digestive enzyme in saliva called amylase (AH-meh-lace) starts to break down some carbohydrates (starches and sugars) in the food.
Muscles in the tongue and mouth work together to swallow the food and move it into the throat (pharynx). The pharynx (FAIR-inks) is a passageway for food and air. A soft flap of tissue called the epiglottis (ep-ih-GLAH-tus) closes over the windpipe when we swallow to keep food and liquid out of the lungs.
The esophagus:
Food travels down a muscular tube in the chest called the esophagus (ih-SAH-fuh-gus). Waves of muscle contractions called peristalsis (per-uh-STALL-sus) force food down through the esophagus to the stomach. A person usually isn't aware of the muscle movements that push food through the digestive tract.
The stomach:
At the end of the esophagus is a muscular ring or valve called a sphincter (SFINK-ter). The sphincter lets food enter the stomach, then squeezes shut to keep food and liquids from flowing back up into the esophagus. The stomach muscles churn and mix the food with digestive juices that have acids and enzymes. These juices help break up food into much smaller pieces. In other words,Cells in the lining of your stomach secrete a strong acid and powerful enzymes that are responsible for the breakdown process.
By the time food is ready to leave the stomach, it has been turned into a thick liquid called chyme (kime). A small muscular valve called the pylorus (pie-LOR-is) controls when chyme is released into the small intestine.
The small intestine:
The small intestine is where many nutrients (like protein, carbohydrates, and fats) get absorbed into the bloodstream. It has three parts:
The duodenum (due-uh-DEE-num). This C-shaped first part is where enzymes from the pancreas and bile from the liver are added to the chyme.
The jejunum (jih-JU-num). This coiled middle part further digests the chyme and absorbs nutrients.
The ileum (IH-lee-um). The final section that leads into the large intestine absorbs nutrients, vitamin B12, and bile acids.
Millions of microscopic, finger-like projections called villi (VIH-lie) line the inside of the small intestine. The villi make lots of surface area for nutrients to get absorbed into the blood. Then blood brings the nutrients to the rest of the body.
While food works its way through the small intestine, three organs that are not part of the alimentary canal help the digestion process:
The liver makes bile, which helps the body absorb fat. It’s located in the top right of the belly.
The gallbladder stores bile until it is needed. It’s hidden just below the liver.
The pancreas makes enzymes that help digest proteins, fats, and carbs. It’s found below the stomach.
Enzymes and bile travel through small pathways (called ducts) into the small intestine, where they help to break down food.
Undigested food and some water travels to the large intestine through a muscular ring called the ileocecal (ill-ee-oh-SEE-kul) valve. This valve prevents food from returning to the small intestine. By the time food reaches the large intestine, the work of absorbing nutrients is nearly finished.
The large intestine:
The large intestine's main job is to remove water from the undigested matter and form solid waste (poop) to be excreted. The large intestine includes three parts:
The cecum (SEE-kum) is the beginning of the large intestine. The appendix is a small, hollow, finger-like pouch that hangs off the end of the cecum. Doctors believe the appendix is left over from an earlier time in human evolution. Today it’s no longer needed to help with digestion.
The colon extends from the cecum up the right side of the abdomen (the ascending colon), across the upper abdomen (transverse colon), and down the left side of the abdomen (descending colon). Then it connects to the rectum.
The rectum is where poop is stored until it leaves the digestive system through the anus as a bowel movement.
It can take days for food to fully pass through the digestive system.
Your hormones and nerves work together to help control the digestive process. Signals flow within your GI tract and back and forth from your GI tract to your brain.
Hormones
Cells lining your stomach and small intestine make and release hormones that control how your digestive system works. These hormones tell your body when to make digestive juices and send signals to your brain that you are hungry or full. Your pancreas also makes hormones that are important to digestion.
Nerves
You have nerves that connect your central nervous system—your brain and spinal cord—to your digestive system and control some digestive functions. For example, when you see or smell food, your brain sends a signal that causes your salivary glands to "make your mouth water" to prepare you to eat.
You also have an enteric nervous system (ENS)—nerves within the walls of your GI tract. When food stretches the walls of your GI tract, the nerves of your ENS release many different substances that speed up or delay the movement of food and the production of digestive juices. The nerves send signals to control the actions of your gut muscles to contract and relax to push food through your intestines.
Believe it or not,
Believe it or not,
Your digestive system is entirely linked to your nervous system, and your nervous system has complete control over various aspects of your digestive function. When the spine is aligned improperly, stress and strain are put on the nerves, leaving them incapable of sending out the necessary signals to your digestive organs that trigger them to work properly.
How can I keep my digestive system healthy?
How can I keep my digestive system healthy?
If you have a medical condition, always ask your healthcare provider what you should do and eat to stay healthy and manage your condition. In general, the following are ways to keep your digestive system healthy:
Drink water often: Water helps the food you eat flow more easily through your digestive system. Low amounts of water in your body (dehydration) is a common cause of constipation.
Include fiber in your diet: Fiber is beneficial to digestion and helps your body have regular bowel movements. Be sure to incorporate both soluble and insoluble fiber into your diet.
Eat a balanced diet: Be sure to eat several servings of fruit and vegetables every day. Choose whole grains over processed grains and try to avoid processed foods in general. Choose poultry and fish more often than red meat and limit all deli (processed) meats. Limit the amount of sugar you consume.
Eat foods with probiotics or take probiotic supplements: Probiotics are good bacteria that help fight off the bad bacteria in your gut. They also make healthy substances that nourish your gut. It can be especially helpful to consume probiotics after you have taken an antibiotic because antibiotics often kill both bad and good bacteria in your gut.
Eat mindfully and chew your food: Eating slowly gives your body time to digest your food properly. It also allows your body to send you cues that it is full. It is important to chew your food thoroughly because it helps to ensure your body has enough saliva (spit) for digestion. Chewing your food fully also makes it easier for your digestive system to absorb the nutrients in the food.
Exercise: Physical activity and gravity help move food through your digestive system. Taking a walk, for example, after you eat a meal can help your body digest the food more easily.
Avoid alcohol and smoking: Alcohol can increase the amount of acid in your stomach and can cause heartburn, acid reflux and stomach ulcers. Smoking almost doubles your risk of having acid reflux. Research has shown that people who have digestive issues that quit smoking have improved symptoms.
Manage your stress: Stress is associated with digestive issues such as constipation, diarrhea and IBS.
Summary
Click through this slideshow to learn more about the digestive system.
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