The digestive system is made up of the gastrointestinal tract—also called the GI tract or digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a . The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion Digestion involves the breakdown of food into smaller. Your digestive system is uniquely designed to turn the food you eat into nutrients, which the body uses for energy, growth and cell repair.
Your large intestine absorbs water, and the waste products of digestion become stool. Nerves and hormones help control the digestive process. Food moves through your GI tract by a process called peristalsis. The large, hollow organs of your GI tract contain a layer of muscle that enables their walls to move. The movement pushes food and liquid through your GI tract and mixes the contents within each organ.
The muscle behind the food contracts and squeezes the food forward, while the muscle in front of the food relaxes to allow the food to move. Food starts to move through your GI tract when you eat. When you swallow, your tongue pushes the food into your throat. A small flap of tissue, called the epiglottis, folds over your windpipe to prevent choking and the food passes into your esophagus. Once you begin swallowing, the process becomes automatic.
Your brain signals the muscles of the esophagus and peristalsis begins. When food reaches the end of your esophagus, a ringlike muscle—called the lower esophageal sphincter —relaxes and lets food pass into your stomach. After food enters your stomach, the stomach muscles mix the food and liquid with digestive juices. The stomach slowly empties its contents, called chyme , into your small intestine. The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine, and push the mixture forward for further digestion.
The walls of the small intestine absorb water and the digested nutrients into your bloodstream. As peristalsis continues, the waste products of the digestive process move into the large intestine. Waste products from the digestive process include undigested parts of food, fluid, and older cells from the lining of your GI tract.
The large intestine absorbs water and changes the waste from liquid into stool. Peristalsis helps move the stool into your rectum. The lower end of your large intestine, the rectum, stores stool until it pushes stool out of your anus during a bowel movement.
Watch this video to see how food moves through your GI tract. As food moves through your GI tract, your digestive organs break the food into smaller parts using:. The digestive process starts in your mouth when you chew. Your salivary glands make saliva , a digestive juice, which moistens food so it moves more easily through your esophagus into your stomach.
Saliva also has an enzyme that begins to break down starches in your food. After you swallow, peristalsis pushes the food down your esophagus into your stomach. Glands in your stomach lining make stomach acid and enzymes that break down food. Muscles of your stomach mix the food with these digestive juices.
Your pancreas makes a digestive juice that has enzymes that break down carbohydrates, fats, and proteins. The pancreas delivers the digestive juice to the small intestine through small tubes called ducts.
Your liver makes a digestive juice called bile that helps digest fats and some vitamins. Bile ducts carry bile from your liver to your gallbladder for storage, or to the small intestine for use. On the inner surface of each cheek, opposite the second upper molar tooth, is a slight elevation that marks the opening of the parotid duct, leading from the parotid salivary gland , which is located in front of the ear. Just behind this gland are four to five mucus-secreting glands, the ducts of which open opposite the last molar tooth.
The roof of the mouth is concave and is formed by the hard and soft palate. The hard palate is formed by the horizontal portions of the two palatine bones and the palatine portions of the maxillae, or upper jaws.
The hard palate is covered by a thick, somewhat pale mucous membrane that is continuous with that of the gums and is bound to the upper jaw and palate bones by firm fibrous tissue.
The soft palate is continuous with the hard palate in front. Posteriorly it is continuous with the mucous membrane covering the floor of the nasal cavity. The soft palate is composed of a strong, thin, fibrous sheet, the palatine aponeurosis, and the glossopalatine and pharyngopalatine muscles. A small projection called the uvula hangs free from the posterior of the soft palate. The floor of the mouth can be seen only when the tongue is raised.
In the midline is a prominent, elevated fold of mucous membrane frenulum linguae that binds each lip to the gums, and on each side of this is a slight fold called a sublingual papilla , from which the ducts of the submandibular salivary glands open. Running outward and backward from each sublingual papilla is a ridge the plica sublingualis that marks the upper edge of the sublingual under the tongue salivary gland and onto which most of the ducts of that gland open.
The gums consist of mucous membranes connected by thick fibrous tissue to the membrane surrounding the bones of the jaw. The gum membrane rises to form a collar around the base of the crown exposed portion of each tooth.
Rich in blood vessels, the gum tissues receive branches from the alveolar arteries; these vessels, called alveolar because of their relationship to the alveoli dentales, or tooth sockets, also supply the teeth and the spongy bone of the upper and lower jaws, in which the teeth are lodged. We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.
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Keeton Nicholas Carr Hightower. Read More on This Topic. Page 1 of Next page The teeth. Learn More in these related Britannica articles: The liver even helps figure out how many nutrients will go to the rest of the body, and how many will stay behind in storage. For example, the liver stores certain vitamins and a type of sugar your body uses for energy.
At 3 or 4 inches around about 7 to 10 centimeters , the large intestine is fatter than the small intestine and it's almost the last stop on the digestive tract. Like the small intestine, it is packed into the body, and would measure 5 feet about 1. The large intestine has a tiny tube with a closed end coming off it called the appendix say: It's part of the digestive tract, but it doesn't seem to do anything, though it can cause big problems because it sometimes gets infected and needs to be removed.
Like we mentioned, after most of the nutrients are removed from the food mixture there is waste left over — stuff your body can't use. This stuff needs to be passed out of the body. Can you guess where it ends up? Well, here's a hint: It goes out with a flush.
Before it goes, it passes through the part of the large intestine called the colon say: CO-lun , which is where the body gets its last chance to absorb the water and some minerals into the blood. As the water leaves the waste product, what's left gets harder and harder as it keeps moving along, until it becomes a solid. Yep, it's poop also called stool or a bowel movement. The large intestine pushes the poop into the rectum say: REK-tum , the very last stop on the digestive tract.
The solid waste stays here until you are ready to go to the bathroom. When you go to the bathroom, you are getting rid of this solid waste by pushing it through the anus say: There's the flush we were talking about! You can help your digestive system by drinking water and eating a healthy diet that includes foods rich in fiber. High-fiber foods, like fruits, vegetables, and whole grains, make it easier for poop to pass through your system. The digestive system is a pretty important part of your body.
Without it, you couldn't get the nutrients you need to grow properly and stay healthy.
Your Digestive System
Learn about the digestive system from Cleveland Clinic, including information on the function of the digestive system, its organs and more. After the first morsel enters your mouth, the many organs of your digestive tract kick into high gear. Here's a look at how your digestive system works, from top to . The digestive system breaks down the food you eat. Learn how in this article for kids.