Emma+Digestive+HW

SCI Human Biology - 1Assigned: 10/9 Due: 10/10**Chapter 8 Digestive System** 1. Describe in your words the processes that occur in the digestive system (ingestion, digestion, movement, absorption, elimination) -Indigestion is when you eat and digestion is the process that breaks down the food particles. Digestion can be either mechanical (mouth and stomach) or chemical ( small intestine). Food moves through each organ to separate the digestible food from the indigestible food. When molecules are small enough and are deemed worthy to be absorbed they cross the wall of the GI tract and enter the blood. The molecules that can not be absorbed are eliminated. They are removed through the process of defecation. 1. Describe the MECHANICAL and CHEMICAL digestion that occurs in the mouth. - mechanical digestion occurs when our teeth chew food into pieces convenient for swallowing. Chemical digestion is the addition of chemicals ( to break down complex molecules into simple structures, 2. What is heartburn? -some of the stomach's contents escape into the esophagus 3. What is a dental cavity? (What causes it?) - Dental cavity is otherwise known as tooth decay. It occurs when bacteria within the mouth metabolize sugar and give off acids, which erode teeth 1. What are the functions of the stomach and how is the wall of the stomach modified to perform these functions? -the stomach stores food, initiates the digestion of protein, and controls the movement of chyme into the small intestine. The oblique layer of the stomach allows the stomach to stretch and to mechanically break down food into smalled fragments that are mixed with gastric juice. 2. What are the functions of the small intestine and how is the wall of the small intestine modified to perform these functions? -small intestine contains enzymes to digest all types of foods, primarily carbohydrates, proteins and fats. The wall of the small intestine absorbs the molecules, namely sugars, amino acids, fatty acids, and glycerol, which are the products of the digestive process. 3. What is lactose intolerance? What causes it and what are the symptoms? -Lactose intolerance is a condition that is for people who do not have the brush border enzyme called lactase and cannot digest lactose. Lactose intolerance is characterized by diarrhea, gas, bloating, and abdominal cramps after drinking milk and other dairy products. 1. What are the three main accessory organs and how do they assist the digestive process? -Pancreas, Liver and gallbladder. Pancreas produce pancreatic juice that break down food. The liver removes poisonous substances from the blood and detoxifies them. The liver is also a storage organ. It removes iron and the vitamins A,K,E,D and B12 from blood and stores them. Liver creates bile which helps regulate the quantity of cholesterol in the blood. Gallbladder stores bile. 2. What is a gallstone? -when liquids stored in the gallbladder harden and turn into stone like material. 3. What is hepatitis? -inflammation of the liver 4. What is cirrhosis? -chronic disease of the liver. First the organ becomes fatty, and then the liver tissue is replaced by inactive fibrous scar tissue. 1. What is the function of the large intestine? -large intestine absorbs water which prevents dehydration of the body. Large intestine also forms feces and is responsible for defecation. 2. Briefly describe the disorders of the large intestine: diarrhea, constipation, diverticulosis, hemorrhoids, IBS, IBD, polyps, cancer. -Diarrhea- infection of the lower intestinal tract and nervous stimulation. -constipation-feces are dry and hard -diverticulosis-little pouches of muscoa that have pushed out through
 * Digestive System**
 * 8.1 Overview of Digestion**
 * 8.2 First Part of the Digestive Tract**
 * 8.3 Stomach and Small Intestine**
 * 8.4 Three accessory organs.**
 * 8.5 Large Intestine**