NN+Chapter+8+Questions


 * Chapter 8 Digestive System**
 * 8.1 Overview of Digestion**
 * 1) Describe in you words the processes that occur in the digestive system (ingestion, digestion, movement, absorption, elimination) **The digestion process starts with ingestion. Ingestion is the process of putting the food into the mouth, chewing, and swallowing. So the digestion begins. Once the food reaches the stomach, it is digested, or broken down to be absorbed in the intestines. The food is moved into the intestines and absorption begins. In the small intestine, the food is further refined and nutrients are absorbed into the blood stream to go where they are needed. The food then moves to the large intestine to have the last useful nutrients, such as water, absorbed into the blood stream. From there the food waits to be eliminated, or released, from the human body back into the world/toilet.**


 * 8.2 First Part of the Digestive Tract**
 * 1) Describe the MECHANICAL and CHEMICAL digestion that occurs in the mouth. **The mechanical process that occurs in the mouth is chewing. When a person chews, they are breaking their food down by force. Chemical digestion is when a chemical breaks down the food, and in the mouth, the saliva performs this function.**
 * 2) What is heartburn? **Heartburn occurs when acid from the stomach goes into the esophagus, causing the lining of the esophagus to erode, and it causes a burning sensation in the part of the esophagus that runs behind the heart, thus it gets its name.**
 * 3) What is a dental cavity? (What causes it?) **A dental cavity appears when the saliva and sugars a person eats secrete an acid that erodes the tooth enamel. If the erosion goes to the pulp of the tooth and reaches the nerves, the pain can be intense. Cavities are caused by eating sweets and other foods that are high in sugar. Cavities can be prevented by limiting sugary foods, and by brushing your teeth, especially when the toothpaste has flouride.**


 * 8.3 Stomach and Small Intestine**
 * 1) What are the functions of the stomach and how is the wall of the stomach modifeied to perform these functions? **The stomach breaks the food down even further so that the food may be absorbed in the intestines. The stomach performs this task with chemical digestion and mechanical digestion. The stomach contracts and uses acids found inside the stomach to break down the food. The food is still chuncky after it leaves the stomach however. The stomach has an especially thick wall so that the acid used to break down the food doesn't erode the stomach wall and go into the rest of the body.**
 * 2) What is lactose intolerance? What causes it and what are the symptoms? **Lactose intolerance is when the person's body doesn't make the enzyme lactase, which breaks down the sugar lactose for digestion. Symptoms include diarrhea, gas, bloating, and cramps.**


 * 8.4 Three accessory organs.**
 * 1) What are the three main accessory organs and how do they assist the digestive process? **The three main accessory organs are the pancreas, the liver, and the gallbladder. The pancreas produces the enzymes necessary for digestion. The liver is like a filter, which filters the blood of all the toxic chemicals that a person intakes, such as alcohol.**
 * 2) What is a gallstone? **A gallstone is liquid from the gallbladder that hardens and becomes like a stone.**
 * 3) What is hepatitis? **Hepatitis is inflammation of the liver. Jaundice is a disease that can occur when a person has had hepatitis.**
 * 4) What is cirrhosis? **When a person has cirrhosis, the liver becomes fatty and is replaced with scar tissues. This disease is particularly common in alcoholics, people with malnutrition, and the obese.**


 * 8.5 Large Intestine**
 * 1) What is the function of the large intestine? **The large intestine absorbs some of the left over nutrients that were not absorbed by the rest of the digestive system; one such nutrient is water. The large intestine absorbs the water taken into the body.** **The large intestine is also home to friendly bacteria that eat some of the left over nutrients such as fiber.**
 * 2) Briefly describe the disorders of the large intestine: diarrhea, constipation, diverticulosis, hemorrhoids, IBS, IBD, polyps, cancer. **Diarrhea occurs when the large intestine does not absorb enough water. In constipation, the feces is hard and dry, usually caused by not defecating when a person needs to. Chronic constipation is associated with hemorrhoids, which are overly large blood vessels in the anus region. Diverticulosis is when pouches of mucosa push through the muscularis. IBS is irritable bowel syndrome, or a spastic colon, and occurs when the muscularis contracts irregularly/spasms. IBD is inflammatory bowel disease, it causes diarrhe, cramps in the abdominal, and rectal bleeding. Polyps are small growths in the rectum. Cancer is a growth of mutated cells that continue to divide indefinately, and do not die.**