Ch.+8+Questions+SLS

Shelby Smith September 3, 2008 Science-Human Bio

Ingestion is where the mouth takes in food, digestion is when food is divided into pieces that can be acted on by digestive enzymes. Movement of the GI tract is crucial to move the food throughout the body. Absorption occurs when unit molecules produced by digestion cross the wall of the GI tract and enter the cells lining the tract. Lastly, elimination is where molecules that cannot be digested need to be eliminated from the body.
 * 8.1 Overview of Digestion**
 * 1. Name and describe the three processes that occur during the digestive process.**

The first layer of the GI tract is the mucosa, this protects the wall from digestive enzymes. Diverticulosis is a condition in which portions of the mucosa layer literally have pushed through other layers and formed pouches, where food can collect. The pouches become inflamed and this is called diverticultis. The second layer of the GI tract is called the submucosa. The illness associated with the submucosa is IBD, inflammatory bowel disease, which is chronic diarrhea, abdominal pain, fever and weight loss. Next layer of the GI tract is the muscularis, and a disease associated with it is IBS, irritable bowel syndrome, which causes the same effects as IBD. Lastly, the final layer of the GI tract is the serosa and an illness associated with this is appendicitis, which is an inflammation of the appendix.
 * 2. What are the four layers of the GI tract? Associate an illness with each of the layers. Describe the illness.**


 * 8.2 The First Part of the Digestive Tract**


 * Define the following vocab...**

Palate: roof of the mouth separating it from the nasal cavities. salivary glands: Produces an enzyme packed mucous water, into the mouth. dental carries: Tooth decay (Cavities.) periodontitis: Bone loss and loosening of the teeth. Pharynx: Where the food and air passages cross. Esophagus: A long narrow tube that takes food to the stomach. Glottis: Opening to the larynx. Epiglottis: trachea moves underneath the epiglottis to cover the glottis. Peristalsis: rhythmic contraction that pushes food through the esophagus. Sphincters: are muscles that encircled the tube and act as valves. Diaphragm: a muscle that separates that thoracic and abdominal cavities.

The mechanical digestion that occurs in the mouth is when the mouth uses the teeth and tongue to break down the food making it easier to digest. The chemical digestion that occurs inside of the mouth starts with the enzyme packed salvia.
 * 3. Describe the mecahnical and chemical digestion that occurs in the mouth.**

The soft palate moves to block of the nasal passage and the epiglottis moves over the trachea.
 * 4. What ordinarily prevents food from entering the nose or entering the trachea when you swallow?**


 * Health Focus Heartburn (p148)**

Heartburn is caused by acid reflux, when some of the stomach’s contects escape into the esophagus.
 * 5. What causes the burning sensation associated with heartburn?**

When heartburn becomes chronic, it turns into GERD, where the acid reflux is more severe and frequent.
 * 6. What is GERD? How is it different from heartburn?**

Two ways that drugs treat GERD is that they neutralize stomach acid, and some take medicine that shut down and reduce acid production.
 * 7. Describe two ways drugs treat GERD.**

Light exercise, avoid high fat meals, eat smaller meals and don’t over eat.
 * 8. Describe ways to avoid heartburn that do not involve drugs.**