The Human Digestive System

The Digestive System

View more presentations from arzbmad16.

Madeline Arzbecker

January 25, 2011

The Human Digestive System

Though many try to understand this vast process of turning food to useful minerals, it is simply an involuntary work of the body. Just as the heart beats every second without a person consciously doing it, food naturally flows through this rollercoaster of organs. Measuring at about thirty feet in length (“Digestive System”), the digestive system leeches the nutrients from food and turns it into something useful. Today, the digestive system still awes people because of the complexity of something that is at first glance perceived to be so simple.

Before we even swallow, the digestive process starts. Saliva starts to form in the mouth as the very thought of food appears our heads (“Your Digestive System.”). Enzymes in the saliva help break down chemicals in the food and make it easier for food to slip down the throat. Located at key spots in the body, enzymes break down large molecules of food into smaller ones (“Digestive System”). Once food enters the mouth, the teeth and the tongue are used to press the food into a soft substance ("Human Digestive System -EnchantedLearning.com."). First the incisors, chiseled teeth in the front of the mouth, are used to bite into the food. With the tongue pushing the food back, canines then begin to tear the food to even more miniscule pieces. Once the chunks of food have reached the back of the mouth, molars are used to turn the bit size pieces of food into a mushy substance that can fit down the throat (“Biblogy: Human Digestive System.”). After the food is swallowed, the rest of the process is involuntary.

Reaching about ten inches long (“Your Digestive System.”), the esophagus is located in the throat and is the next step in the digestive system. Its main job is to carry food to the stomach, which is done in about three to eight seconds (“Esophagus & Stomach.”). Food is transported through the esophagus by using wave like muscles called peristalsis. Peristalsis allows you to drink even when you are upside down because it slowly squeezes food down the esophagus ("Human Digestive System - EnchantedLearning.com.").

Located in the back of your throat, along with your esophagus, is the wind pipe. To make sure that air goes down the wind pipe and food goes down the esophagus, a flap called the epiglottis covers the wind pipe while we eat. Sometimes when we drink or eat something really fast we begin to involuntarily cough. This is because the epiglottis didn't have enough time to close, so the food went into the wind pipe (“Your Digestive System.”).

When food leaves the esophagus it ends up in the stomach; there it has three main jobs. The stomach stores food, breaks down food into a liquid, and slowly enters the mixture into the small intestine. It is like a giant mixer that breaks down food with help from the muscles on the walls of the stomach. Helping the digestive process, gastric juices flow from the walls of the stomach (“Your Digestive System.”). These include enzymes pepsin, which targets proteins, lipase, which works on fats, and hydrochloric acid that dissolves the stomachs contents while killing harmful bacteria. As the stomach churns the food, all these juices combine to make a liquid substance call chyme. Chyme is then sealed in the stomach between two ring-like pinchers for several hours. When the mixer is finally ready to enter the small intestine, the muscles release it in small bursts (“Digestive System”).

As chyme travels through the small intestine, it is broken down even more. Fitting in about a two inch long space, the small intestine helps the body absorb vitamins, minerals, proteins, carbohydrates, and fats. Connected to the small intestine, are three main organs -- pancreas, gallbladder, and liver --- that help the small intestine digest different food. The pancreas creates juices that help the body absorb fats and proteins. Meanwhile, the liver juice, referred to as bile, sucks fats into the bloodstream. Working with the liver, the gallbladder stores the liver's bile until it is ready to be used (“Your Digestive System.”).

The small intestine is divided into three parts, the duodenum, the jejunum, and the ileum. As chyme enters the dudenum, it processes mucus to protect the inner lining of the small intestine from the harmful chemicals in the chyme. Once the chyme has traveled through all three layers it is turned into a very thin watery mixture. It can take up to four hours to go through this vast, 22 foot long organ. When the final nutrients are taken out of the food, it is entered into the large intestine (“Digestive System”).

Joining the small intestine in the lower right abdomen of the body (“Bibliogy: Human Digestive System.”), the large intestine is the final organ in the digestive system. Before food leaves the body, it has to travel through the colon in the large intestine. There is three main parts to it, the ascending, transverse, and descending colon. As the final water and minerals are sucked out of the food, it turns into a solid by being mixed with dead skin cells. This solid is then moved to the rectum until it is ready to depart the body through the anus (“Your Digestive System.”).

This delicate process of intricate organs is so beneficial to our health that we need to do the best we can to take care of it. Malfunction or just poor dieting can result in anything from heartburn (Gilson) to more serious diseases that can result in heart failure. That is why proper nutrition is a keen aspect to living a healthy and long life. We need to do the best we can to maintain a healthy digestive system because we only get one; one digestive system, one body, and one life is all we get. Continuing to awe people across the nation, it is very important to have knowledge of how this system runs in order to achieve a healthy body.

Works Cited

"Biology: Human Digestive System ." Get Homework Help with CliffsNotes Study Guides . N.p.,     n.d. Web. 5 Jan. 2012. <http://www.cliffsnotes.com/study_guide/Human-Digestive-System.topicArticleId-8741,articleId-8705.html>.

"Digestive System, Digestion Information, Digestive System Facts, News, Photos -National Geographic." Science and Space Facts, Science and Space, Human Body, Health, Earth, Human Disease - National Geographic. N.p., n.d. Web. 4 Jan. 2012. <http://science.nationalgeographic.com/science/health-and-human-body/human-body/digestive-system-article/#>.

"Esophagus & Stomach." Bodyteen. N.p., n.d. Web. 9 Jan. 2012. <http://www.bodyteen.com/andist.html>.

Gillson,  Sharon. "Heartburn 101 - What Causes Heartburn - Heartburn Causes - Acid Reflux Causes - Mechanisms of Acid Reflux - Heartburn Triggers - GERD." Heartburn - Heartburn Causes - Heartburn Prevention - Heartburn Treatment - GERD - GERD Causes - GERD Prevention - GERD Treatment. N.p., n.d. Web. 25 Jan. 2012. <http://heartburn.about.com/cs/emailcourses/qt/heartburn10101.htm>.

"Human Digestive System - EnchantedLearning.com." ENCHANTED LEARNING HOME PAGE. N.p., n.d. Web. 4 Jan. 2012. <http://www.enchantedlearning.com/subjects/anatomy/digestive/>.

"Your Digestive System ." KidsHealth - the Web's most visited site about children's health. N.p., n.d. Web. 3 Jan. 2012. <http://kidshealth.org/kid/htbw/digestive_system.html#>.