bio short essay

Dana Deuel
Prof. Sullivan Deuel 1
BIO 106
May 4th, 2015

Digestion is important for breaking down food into nutrients which the body uses for energy, growth and cell repair. When I am chowing down my steak and potatoes, my digestive system is doing that exact thing. Our digestive system breaks down food into smaller molecules and into nutrients for the body. These nutrients include carbohydrates, protein, fat and vitamins.
The digestive system is made up of the GI tract, also known as the digestive tract. The GI tract is a series of hallow organs going from the mouth to the anus. The organs that make up this tract are the mouth, esophagus, stomach, small intestine and large intestine which includes the rectum and anus. There are also organs of the digestive system that are solid and help the body digest the food. These include the liver, pancreas and gallbladder.
Once I have taken a bite out of my delicious favorite meal, the digestive system gets to work. It all begins in the mouth, chewing the food small enough to swallow. Salvia is squirted into the food to moisten and soften the food. Salvia contains enzymes, which break down the starches in food. Once the tongue forms the food into a ball to be swallowed, it is sent down the pharynx. The pharynx contains sphincters that help keep your food down once you swallow. Next, it makes its way to the esophagus, which is simply a transportation tube from the mouth to the stomach. It then reaches the stomach, which uses chemicals to make the food particles tinier. These chemicals are called gastric juices and include hydrochloric acid and enzymes. Once the stomach mixes with the chemicals, it is formed into a cream-like liquid called chyme. The gallbladder takes over from here hitting the food with more chemicals, one of them called bile. Bile is mixed with our food breaking down the fat into droplets, which will supply us with energy later on. From there, the pancreas uses digestive juice to break down carbohydrates, which would include the potatoes I had for dinner and proteins including the steak. One of the last processes are in the small intestine as the food passes through and is mixed with even more new chemicals. Along the walls of the intestine are villi. Blood vessels in the villi can absorb the tiny food molecules and send them to the rest of your body through the blood. Last but not least is the large intestine. Whatever the body cannot use is sent to the large intestine where the water is removed and sent through the blood stream. Food spends about 12 hours in the large intestine as undigested food is stored in the rectum until it leaves the body, this is called solid waste feces.