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**Major Functions of the Digestive System**

﻿1. __Ingestion__- take food into the digestive tract. This usually happens through the mouth. 2. __Propulsion-__ The proces where food movesfrom mouth to anus. Peristatisis (propelling food through the digestive tract) invovles waves of contraction of the muscles in the organ wall. 3. __Mechanical Digestion__- physically prepares food for chemical digestion by enzymes. This includes chewing, mixing food with salvia, churning and mexing food in the stomach. 4. __Chemical Digestion-__ when large food molecules are broken down to their monomers, which are small enough to be absorbed by the GI tract lining. 5.__Absorpton__- absorb nutrients into blood from small intestines. 6. __Defecation__- Removing indigestable things from the body through the anus in the form of feces (pooping)

__Structure & Function of the Microvilli__ The main function of the small intestines is to absorb all the food that goes through it. The small intestines contains these microscopic hairs calling microvilli. Its like a mop cleaning a water spill; it absorbs not just water but food that enter the small intestines. The microvilli is an advantage for the small intestines because there are thousands maybe even millions of microscopic microvilli's in the small intestines which is good because they can help absorb the food faster.

__**Structure & Function** __

**Salivary Glands**: The glands found in and around your mouth and throat are the major saliva glands calling the parotid. Submandibular and sublingual glands. They all secrete salvia into your mouth, through your teeth and the ducts on the bottom of your mouth. Besides the major glands there are minor glands in your lips, cheeks and other linings of your mouth and throat. Salvia glands produce the salvia used to moisten your mouth, initiate digestion, and help prevent your teeth from decay.


 * Mouth: **food is broken down by chewing and the chemical action of salivary enzymes.


 * Esophagus: **long tube that runs from the mouth to stomach. Uses "rythemic" or wave-like muscle movements called peristalsis and it forces food down the throat into the stomach. The movement of our muscles gives us the ability to eat or drink upside down.


 * Stomach: **A large sack like organ that churns the chewed up food and bathes it in a very strong acid called gastric acid. When the food is partly digested and mixed with stomach acids it called chyme.


 * <span style="font-family: Arial,Helvetica,sans-serif;">Small Intestine: **<span style="font-family: Arial,Helvetica,sans-serif;">After the food is digested in the stomach it enters the duodenum, the first part of the small intestine. After it goes through that the food enters the jejunum and the ileum (the tube and final parts of the intestine). While in the small intestine bile (a digestive chemical that is produced in the liver, stored in the bladder and secreted into the small intestine) pancreatic enzymes and other digestive enzymes produced by the small intestine help to break down food even more.


 * <span style="font-family: Arial,Helvetica,sans-serif;">Appendix: **<span style="font-family: Arial,Helvetica,sans-serif;"> A small sac located near the start of the large intestine.


 * <span style="font-family: Arial,Helvetica,sans-serif;">Large Intestine: **<span style="font-family: Arial,Helvetica,sans-serif;">After going through the small intestine food passes into the large intestine. In the large intestine some of the water and electrolights are removed from the food. The first part of the large intestine is called the cecum (first part of the large intestine, connected to appendix). Food then travels upward in the ascending colon and the food travels across the abdomen in the tranverse colon, and then goes back down the other side of the body in the descending colon and then through the sigmoid colon (the part of the large intestine between the descending colon and rectum)


 * <span style="font-family: Arial,Helvetica,sans-serif;">Gallbladder: **<span style="font-family: Arial,Helvetica,sans-serif;">The gallbladder is like an active storage cell that absorbs mineral salts and water from the liver and then it converts the salts and water into a thick mucus substance (bile) which is to be released when food is in the stomach. Bile is released from the gallbladder to the duodenum (first part of the small intestine). A secreation in the gallbladder to contract and expel its content into the duodenum. It is a help to more and break down food in digestion.


 * <span style="font-family: Arial,Helvetica,sans-serif;">Liver: **<span style="font-family: Arial,Helvetica,sans-serif;">Blood is passed through the heart to be cleansed and process nutritional molecules that are distributed to the tissues. When we eat more, blood is diverted into the intestines to deal with the digestive process. When we don't eat 3/4 of blood comes from the intestines. The liver detoxifies blood cells by mixing them with bile by chemical alterations to less toxic substances. Many chemical compounds are alos deactivated by the liver. The liver converts glucose, synthesises triglycerides and cholestrol, breaks down fatty acids and produces proteins needed to clot blood.


 * <span style="font-family: Arial,Helvetica,sans-serif;">Pancreas: **<span style="font-family: Arial,Helvetica,sans-serif;">Long, flat gland in your belly. It sits behind the stomach and produces enzymes that help in digestion. Insulin and glucagon, which help control the level of gluclose in the blood, are mand in the pancreas.


 * <span style="font-family: Arial,Helvetica,sans-serif;">Rectum: **<span style="font-family: Arial,Helvetica,sans-serif;">Lower part of the large intestine where feces are stored before they are excreted.

What is gas? Where does it come from? Gas is made of odorless carbon dioxide with hydrogen sulphide(causes the bad smell). It is made in your stomach when you breakdown food or when you swallow air during meals.

What is GERD? Why does it happen? Gastroesophageal reflux disease. It affects the lower esophageal sphincter muscle connecting the esophagus with the stomach. It happens by hiatal hernia. The lower esophageal sphincter is weaken and allows the stomach contents to go into the esophagus causes heart burn.

Where is the food broken down? The mouth, stomach, and small intestine. Where is food absorbed? Most food is absorbed in the small intestine Carbs-Starch and sugar are broken into simple molecules by enzymes in saliva, juice produced by the pancreas and the lining of the small intestine. Starch is broken down by enzyme in saliva and pancreatic juice and turned into maltose. The lining in the small intestine then turns maltose into glucose. Glucose then goes into the bloodstream then to the liver. There it is stored or used as energy for the body. Sucrose (sugar) is digested by enzymes lining in the small intestine and turned into glucose and fructose. Then they are absorbed through the intestine into the blood. Milk has lactose which changes into absorbable molecules by another type of enzyme in the lining. Proteins are broken down by the juice in the stomach. Then the small intestine completes the breakdown of proteins and turns them into amino acids. Amino acids are then absorbed through the small intestine and into the blood stream to be transported. Lipids dissolve into the watery content of the intestine. Acids from the liver dissolve fat and turn it into small drops. Pancreatic and intestinal enzymes break down large fat molecules. Bile acids, fatty acids, and cholesterol combine to move into cells in the mucosa then transported to the veins in the chest area to be stored. media type="youtube" key="08VyJOEcDos" height="531" width="645"