By: Cameron Farrell, Alex Phan, Thao Cao Digestive System By: Cameron Farrell, Alex Phan, Thao Cao

Introduction The Digestive system’s purpose is to, of course, digest food and water. It’s the conversion of food/water into stuff for the body to use. Though the digestive system is not as easy as it sounds there are many parts/organs that make up this system. There are many steps that the digestive system follows each time a human eats something.

Parts & Organs Mouth Stomach Esophagus Liver Small intestine Pancreas Large intestine Gall bladder Rectum Enzymes Teeth Anus

How The System Works First the teeth in your mouth grinds up the food you eat. Then the salivary glands in your mouth releases saliva to soften the food. This process of grinding down food is called mechanical digestion. The food then travels down the esophagus. The walls of the esophagus move the food down in a wave-like motion. At the bottom of the esophagus is a lower esophageal sphincter that lets food into the stomach. The pancreas then releases enzymes into the stomach. The release of enzymes starts the process of chemical digestion. The enzymes are juices/acids that break down the food.

How The System Works Once the food is inside the stomach, digestive juices get to work. The digestive juices break down carbohydrates and proteins and sometimes it can kill bad bacteria. What is left is called chyme. This mixture then travels into the small intestine. The small intestine is the main part of digestion because it absorbs nutrients. The nutrients are absorbed by little bristle like things called villi. The small intestine is about 20 to maybe 30 feet long.

How The System Works Other important parts of the digestive system includes the liver, gallbladder, and the pancreas. The liver may not seem very important but it is because the liver produces cholesterol and blood proteins. The liver also gets rid of any toxic materials that could harm your body; like alcohol, drugs, and poisons. The gallbladder is a small storage sac that stores bile from the liver. The pancreas isn’t that big but it is important to digesting because it produces enzymes to digest fats and proteins.

How The System Works The next to last step is for the food to travel through the large intestine. The large intestine is about 4 to 5 feet long.The large intestine has certain bacteria that produce special nutrients like vitamin K. The bacteria also has bacteria that helps boost immunity function and protects against any harmful bacteria that harms the body. There’s a part of the large intestine called the colon; the colon is the part where all the water is absorbed and the important minerals goes into the blood to use.

How The System Works The very last step for the digestive system is to get rid of the unnecessary waste. Since all of the water, important proteins, and nutrients is gone the food is now hard and no longer mushy. So since the remains of the food is no longer needed the body needs to get rid of the waste. So the remains is collected in the rectum and is then extracted from the body through the anus. If the waste is not extracted then the body could get very sick. This is the process of digesting each time you eat something.

Interactions With Other Systems The digestive system certainly cannot work alone it needs help from the other systems. So the digestive system interacts with two other systems; the circulatory system and the excretory system. The circulatory system helps by carrying chemical signs that help control the speed of digestion. The excretory system helps by disposing of the unnecessary waste from the body.

Favorite Website http://www.biology4kids.com/files/systems_main.html This is one of the most used websites in our group because it contains the information needed. The information is also very detailed so that it is very easy to understand.

References The websites used: http://www.healthyme.com/Imagebank/digestive .swf http://www.uen.org/utahlink/tours/tourFrames.cqi?tourid=13125 http://www.kidsbiology.com/humanbiology/index.php http://www.ehc.com/vbody.asp