Digestive System


Functions



The digestive system includes the digestive tract and its accessory organs, which process food into molecules that can be absorbed and utilized by the cells of the body. Food is broken down, little by little, until the molecules are
small enough to be soaked up and the waste products are gone.The digestive system prepares nutrients for utilization by body cells through six activities, or functions.

Major Organs




Teeth

There are several different type of teeth. Each tooth has a different purpose.
Incisors: 8 front teeth 4 on the top and 4 on the bottom. Shaped for biting and cutting.
Cuspids: 4 teeth located on either side of the incisors. 2 on the top and 2 on the bottom. Shaped for tearing food.
Bicuspids:8 located behind cuspids. 4 on the top and 4 on the bottom. Shaped for crushing food.
Molars: 8 Double rooted teeth with bumpy chewing surfaces. 4 on the top and 4 on the bottom. Shaped for grinding food.

Stomach
The Stomach plays an important part in the digestive system because it stores the food and breaks it down using digestive fluid. A stomach can change shape depending on what position you are in and it can hold about 1qt of food and fluid. The down food travels from the esophagus, through the stomach and down into the small intestine. Your stomach is attached to the end of the esophagus. It's a stretchy sack shaped like the letter J. It has three important jobs. Your stomach has three important jobs. 1. To store the food that you have eaten. 2.To break down the food into a liquidy mixture. 3.To slowly empty that liquidy mixture into the small intestine. The stomach plays an imporant role because it is the one to make acids to break down the food and let it be digested.






How it works


Your digestive system starts working even before you start eating. If you think about food, smell it or even see it your digestion begins. It begins by saliva forming. When you eat your saliva breaks down the chemicals in food. It makes it easier to swallow and later digest. Your tongue helps by moving the food around while your teeth chew it. When you are ready to swallow it your tongue pushes a tiny bit of food called the bolus toward the back of your throat. Then it goes to your esophagus. To start Phase 2 of your digestive system. At the back of your throat is a windpipe. When you swallow food, the epiglottis flaps down over the windpipe and it doesn’t allow food to get in the windpipe. Once your throat enters the esophagus it doesn’t just go straight to the stomach, muscles in the esophagus push it down to the stomach. This takes about 2 to 3 seconds. Your stomach is connected to the end of your esophagus. Your stomach does three important things:
1. It stores the food you’ve eaten.
2. Break down food into a liquid mixture.
3. To empty the liquid into the small intestines.
Your stomach is like a mixer that mashes all your food together in smaller and smaller pieces. It does that with help from the gastric juices that come from the walls. The gastric juices also kill bacteria. Then the food goes to the small intestine. The small intestine is about 22 feet long and 2 inches around. It’s packed beneath the stomach. The small intestine breaks down the food mixture even more so your body can absorb all the vitamins, minerals, proteins, carbohydrates, and fats. The small intestine does that with thepancreas, liver and gallbladder. These organs send different juices to the small intestine and help digest it even more. Pancreas juices help digest fats and protein, the liver juice brings the fats to the bloodstream, and the gallbladder stores the juices for when the body needs it. Your food may spend up to 4 hours in the small intestine making a thin watery mixture. It does that because it may go in your blood. The next step is for the food that you cannot use and it goes to the large intestine. First it goes through the liver which filters out harmful bacteria and waste. 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. Now it's in the large intestine. It is 3 or 4 inches around which fatter than the small intestine. And if you spread it, it would be 5 feet long! Before it goes, it passes through the part of the large intestine called the colon, 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, "poop". The large intestine pushes the poop into the rectum, the very last stop on the digestive tract. You are getting rid of this solid waste by pushing it through the anus.

How it works with other systems (at least 3 different systems)


The digestive system works closely with the circulatory system to get the nutrients to your body.The digestive system also works with your excretory system.The main organ involved in digestion is the liver witch is 2.5 percent of your body wait. The pancreas also helps your digestive system that has chemicals that break down the things you eat.The digestive systems works with integumentary system. The Integumentary system takes in vitamin D from the sunlight. The vitamin D helps absorb calcium in food.

Sources

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