Notes: Digestive system

OrganFunction Mouth/Salivar y Gland Digestion start with every bite. Chewing breaks the food into pieces that are more easily digested, while saliva mixed with food to begin to break it down into a form your body can use and absorb. Salivary glands produce amylase, an enzyme that speeds up the breakdown of starch and sugars.

OrganFunction Tongue Muscular organ necessary for speech, chewing, and swallowing. In combination with the cheeks, it is able to guide and maintain food between the teeth until chewing and swallowing is complete.

OrganFunction Appendix Beginning of the large intestine in which the small intestine empties into. Scientists don't know whether it has a useful purpose to humans. They speculate it is disappearing from the human species over evolutionary time. Appendix

OrganFunction Esophagus Located in your throat near your trachea. It received food from your mouth when you swallow. By means of a series of muscular contractions called peristalsis, the esophagus delivers food to your stomach. We call this the "food tube."

OrganFunction Stomach Hollow organ that holds food. Cells in the lining of the stomach make a strong acid and more enzymes to continue to break down food. Contents of stomach are released into small intestine.

OrganFunction Pancreas Secretes digestive enzymes into small intestine that breaks down protein, fats, and carbohydrates. Also makes insulin and releases it into the bloodstream, which helps control sugar levels.

OrganFunction Small Intestine Breaks down food using enzymes from pancreas and bile from liver. Food starts out as semi-solid, by the end of the small intestine it is in a semi-liquid form. Nutrients are then absorbed and leftover waste is passed onto large intestine.

OrganFunction Large Intestine Also known as the colon. Responsible for processing waste so emptying bowels is easier. As waste passes through large intestine, water is absorbed. It takes about 36 hours for the waste to move through the entire large intestine until it empties out the anus.

OrganFunction Gallbladder Stores and concentrates bile, releases it into small intestine to help absorb and digest fats.

OrganFunction Liver Process nutrients that have been absorbed from the small intestine. Produces bile that digests fat in small intestine. Is the "chemical factory" that converts the raw materials absorbed into chemicals the body needs to function. Detoxifies harmful chemicals (alcohol).

OrganFunction Spleen Is primarily your blood filter. It destroys old red blood cells and holds back up cells in case you lose some quickly. You can live without your spleen, but you are more likely to get sick as it helps your immune system.

OrganFunction Rectum Connects large intestine to anus. Rectum holds waste/feces until message is sent to the brain telling you to get rid of it.

OrganFunction AnusLast part of the digestive tract. Releases waste.

The Pathway of Food 1. Food enters the mouth where it is cut mechanically by the teeth. 2. Salivary glands contain amylase (enzyme) which begins the chemical digestion of the food. 3. The food is pushed down the pharynx and the epiglottis seals off the airway. 4. The food moves down the esophagus by smooth muscle contractions called peristalsis.

The Pathway of Food 5. As the food drops into the stomach the cardiac sphincter muscle closes behind it (preventing "heart burn" - acid reflux!) 6. The stomach, a large muscular sac organ, contains gastric juices that continue chemical digestion. 7. Bile made in the liver is stored in the gallbladder to prepare fats for better digestion.

The Pathway of Food 8. The broken down food mixture enters the last parts of the small intestine. The walls of the intestine are folded into finger-like projections called microvilli, which maximizes the surface area and allows for fast absorption. 9. Food now passes into the colon or large intestine (1.5m long and 5 cm wide). Here, most water is absorbed as well as vitamins K and B. 10. Undigested material, called feces, exits through the colon, rectum, and anus.