digestive+system+questions+EAT

1. Describe in you words the processes that occur in the digestive system (ingestion, digestion, movement, absorption, elimination) 1. Describe the MECHANICAL and CHEMICAL digestion that occurs in the mouth. 2. What is heartburn? 3. What is a dental cavity? (What causes it?) 1. What are the functions of the stomach and how is the wall of the stomach modified to perform these functions? 2. What are the functions of the small intestine and how is the wall of the small intestine modified to perform these functions? 3. What is lactose intolerance? What causes it and what are the symptoms? 1. What are the three main accessory organs and how do they assist the digestive process?
 * Chapter 8 Digestive System**
 * 8.1 Overview of Digestion**
 * ingestion is when the body consumes food and can be associated with our diet.
 * digestion is either mechanical or chemical.
 * mechanical digestion is when the food is broken up so that it can move on and be digested by the digestive enzymes (when we cut up our food we are helping this process) mechanical digestion is mainly in the mouth and stomach.
 * chemical digestion starts in the mouth but isnt dont until the food is in the small intestine. the thick liquid-like food that goes into the small intestine is called "chyme"
 * movement is when the food moves through the digestive tract. it is important that the food moves so that it can fulfill its other functions.
 * absorption is when the molecules made by digestion (nutrients) move across the wall of the "GI" tract and enters the cells that are lining the GI tract. the nutrients then go into the blood streem for delivery of nutrients to the cells.
 * elimination is when molecules that cannot be digested exit the body through the anus in the form of feces.
 * 8.2 First Part of the Digestive Tract**
 * mechanical digestion is done by the teeth in the mouth. the teeth break the food up into pieces so that they body is able to swallow the food.
 * chemical digestion is when chemicals are added to break down the food into smaller molecules. the salivary glands in the mouth break down the starches that are in food.
 * is caused by acid reflus and is when some of the contents in the stomach move into the esophagus.
 * they are when bacteria in the mouth create sugar and give off acids that then erode the teeth.
 * 8.3 Stomach and Small Intestine**
 * the stomach is a thick J-shaped organ that is on the left side of the body under the diaphragm. the stomach stores food, starts the digestion of protien, and controls the movement of chyme to the small intestine. the stomach does not absorb nutrients but it does absorb alcohol because it is a fat soluble. the wall has four later but two of them are changed for specific functions. the muscularis has three layers of smooth muscle- along with the circular and longitudinal layer the stomach has a layer of smooth muscle that runs obliquely to the other two. the oblique layer lets the stomach stretch and mechanically digest the food into smaller parts that are then mixed with gastric juices.
 * the small intestien hs enzymes that allows it to digest food mostly carbohydrates, proteins and fats. the wall absorbs the molecules sugar, amino acids, fatty actings, and glycerol (which are the products of the digestive process). the mucosa of the small intestine changes for absorption. the mucosa has fingerlike projections called "villi" which give the wall a soft, velvety appearance.
 * when a person cannot digest lactose. it comes when people lack the enzyme lactase. they symptoms are diarrhea, gas, bloating, and abdominal cramps after having dairy products.
 * 8.4 Three accessory organs.**
 * pancreas
 * the pancreas makes pancreatic juices that contain sodium bicarbonate and digestive enzymes for all foods. the pancrease also releases insulin into the blood stream.
 * the liver
 * is a major metabolic gland. it is in the upper-rightsection of the abdomine... unde