HUN 1201 Fall 2011 Exam II Study Guide Chapter 3 1 What is the difference between hunger and appetite Hunger is the physiological drive for food It is nonspecific and can be satisfied by a variety of different foods Appetite is the psychological desire to consume specific foods It is aroused by environmental cues 2 What are the roles of each of the following in digestion a Hypothalamus triggers feelings of hunger of satiation fullness b Sphincters are muscles that control the passage of food material from one GIT organ to the next c Taste and Olfactory Receptors taste receptors detect distinct tastes such as bitter sweet salty sour and umami meaty savory flavor Olfactory receptors detect aromas or smells of foods d Epiglottis covers the opening of the trachea during swallowing 3 What is the order of organs in the digestive tract Mouth esophagus stomach small intestine large intestine accessory organs gallbladder liver pancreas 4 Define the following and know where they occur a Peristalsis Is the muscular contractions that move food through the GI tract Pushes the content from one area to the next b Segmentation Rhythmic contraction of circular muscles in the intestinal wall Mixes the chyme and enhances its contact with digestive enzymes and enterocytes c Haustration Segmentation within the colon that contract sluggishly to move contents 5 What are the components of gastric juice What role does each play Gastric juice contains Hydrochloric Acid HCI Pepsin Gastric lipase and Intrinsic factor HCI denatures proteins and activates pepsin Pepsin is an enzyme used to digest protein Gastric lipase is an enzyme to digest fat And intrinsic factor is the protein to absorb vitamin B12 6 What are the functions of chyme mucus and bicarbonate in the stomach Chyme is a liquid product of mechanical and chemical digestion in the stomach Mucus is the layer that protects the stomach lining from the acid in gastric juices And Bicarbonate neutralizes the acid 7 What are the 3 sections of the small intestine Duodeum Jejunum and Ileum 8 What are the major functions of the large intestine The large intestine is also referred to as the colon In the colon bacteria assist with the final digestion of food Its main function is to store undigested food material and absorb water short chain fatty acids and electrolytes 9 Review the digestive enzymes and hormones of the GIT and their function Table 3 1 10 What are the three accessory organs and their functions The three accessory organs are the gallbladder the pancreas and the live The gallbladder stores bile a greenish fluid produced by the liver CCK signals the gallbladder to release bile and bile emulsifies the lipids The pancreas manufactures holds and secretes digestive enzymes The pancreas stores enzymes in the inactive form In the pancreas insulin and glucagon are hormones that are produced to regulate blood glucose Then bicarbonate is secreted to neutralize chyme The liver is one of the most important organs in the body It synthesizes chemicals for metabolism receives the products of digestion via the portal vein releases glucose stores vitamins manufactures blood proteins and filters the blood to remove wastes and toxins 11 Describe the absorptive surface of the GIT The mucosal membrane is the lining of the GI tract that has specific structures to facilitate absorption Chapter 4 1 What is the difference between simple and complex carbohydrates Know examples and sources of each Simple carbohydrates require little digestion and thus are a quick energy source Fruits fruit juices and milk contain simple sugars carbohydrates that provide valuable nutrients in addition to an energy boost Candies table sugar alcoholic beverages and sweetened soft drinks are simple sugar sources that provide calories but usually no nutrients Complex carbohydrates are found in grains some vegetables and legumes They are starches and require more digestion than simple carbohydrates Rich in B vitamins fiber and iron complex carbohydrates from grains are the body s best source of energy because they are burned in a constant time released manner They provide sustained energy for athletic events and can help manage blood sugar irregularities The fiber found in complex carbohydrates fruits and vegetables can help lower blood cholesterol in some people when eaten as part of a low fat diet a Monosaccharides vs disaccharides Monosaccharides contain one molecule glucose Fructose and galactose Disaccharides contain two molecules lactose maltose and sucrose b Oligosaccharides vs polysaccharides Oligosaccharides contain 3 10 monosaccharides Polysaccharides consist of hundreds to thousands of glucose molecules 2 What is the difference between starch and glycogen Starch is the plant from of storing carbohydrates and glycogen is the animal human form of glucose Starch is found in food sources such as grains legumes fruits and vegetables Glycogen is not found in food and therefore not a source of dietary carbohydrate 3 What is the difference between soluble and insoluble fibers Soluble fibers dissolve in water and are viscous and gel forming They are fermentable digested by intestinal bacteria Insoluble fibers are not soluble in water and nonviscous They cannot be fermented by bacteria in the colon They promote regular bowel movements and include whole grains seeds legumes fruits and veggies 4 Where does carbohydrate digestion occur Which enzymes breakdown carbohydrates and where in the GIT Carbohydrate digestion does NOT occur in the stomach It occurs in the small intestine Pancreatic amylase is the enzyme that is produced in the pancreas and secreted in the small intestine to digest carbohydrates into maltose 5 What happens to excess carbohydrates in the body Excess glucose in the body is stored as glycogen in the liver and muscles 6 Which hormones are involved in blood glucose regulation and how do they affect blood glucose The hormones involved in blood glucose regulation are insulin glucagon ephinephrine norepinephrine cortisol and growth hormone Insulin stimulates the liver to take up glucose and convert it to glycogen Glucagon stimulates the liver to convert glycogen to glucose insulin and glucagon are reverse functions Epinephrine and norepinephrine are secreted by the adrenal glands and nerve endings when blood glucose is low This is like fight or flight Cortisol and growth hormone are secreted by the adrenal glands to act on the liver muscle and adipose or fat tissue 7 Explain
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