Editing Classroom Digestion (section)

== Why This Works ==

The ''Digestive Tract'' is the path through our bodies that our food takes when we eat. There are several steps to the digestion process, and this is a simplified way to look at that process. Below is a list of the steps and what part of the digestive tract they represent.
# The first volunteers are the saliva in our mouths. Saliva helps to break down the outside of food, and provides lubrication so it slides more easily down our throat. Saliva is produced in a gland underneath the tongue, and is secreted from the cheeks and tongue.
# The second volunteers are the chewing process. When we chew our food, we make it easier for the later processes to get to the nutrients inside the food. Our mouths have different kinds of teeth to help break down different kinds of food, and we have strong jaw muscles so we can thoroughly chew up and break down our food.
# The third volunteers are the stomach. In our stomach the outer layers of the food are broken down further, exposing the inner layers where the nutrients are kept. The stomach produces hydrochloric acid, and the stomach lining is replaced every few weeks because our stomach acid is strong enough to break it down!
# The fourth volunteers are the first step in our small intestines. Our small intestines break open the final layers of the food, revealing the nutrients that are inside. This happens because of various compounds that the body produces to help neutralize the acid from the stomach as well as the gut flora working to break the food down further.
# The fifth volunteers are the second step in our small intestines. The small intestines extract the nutrients from food that our bodies can use and need, and works to extract as many nutrients as possible from it. Our gut flora also help with this, and some are able to produce vitamins for us while breaking the food down.
# The sixth volunteers are the large intestine. The large intestine compresses the food waste (the bags) down, making it easier to remove it from our bodies. By this point, 60% of the waste is from old and dead bacteria cells from our small intestine, and the rest of it is food waste that our bodies cannot use.
# The seventh volunteers are the rectum. The rectum expels the food waste from our bodies, which keeps out anything in the food that could be harmful if not removed. This also shows us an important fact about the digestive tract: the digestive tract is, essentially, a giant tube through the body! With the mouth as one opening and the rectum as the other, this tube allows us to take in food, extract the good parts, and remove the bad parts without the bad parts getting inside our cells or other organs!