HUN 1201 Study Guide for Exam 2 Name Chapter 3 1 What is the difference between hunger and appetite Hunger Appetite Physiological drive for food Non specific can be satisfied by a variety of different foods Psychological desire to consume specific foods Aroused by environmental cues 2 What are the roles of each of the following in digestion a Hypothalamus triggers feelings of hunger or fullness located above the pituitary gland in an area of the brain that regulates involuntary activities integrates signals from nerve cells hormones and the types of foods consumed muscles that control the passage of food from one GI tract organ to the next b Sphincters c Chewing e Epiglottis f Bicarbonate moistens the food and mechanically breaks it into smaller pieces exposes more surface area to digestive juices d Taste and Olfactory Receptors Taste detect distinct tastes bitter sweet salty sour umami Olfactory detect aromas of foods covers the opening to the trachea during swallowing neutralize acids found in saliva the lining of our stomach 3 What is the order of organs in the digestive tract Mouth Pharynx Esophagus Stomach Small Intestine Large Intestine Rectum 4 Define the following and know where they occur a Peristalsis the rhythmic muscle contraction that move food through the GI tract occurs throughout the GI tract Rhythmic contraction of circular muscles in the intestinal wall Mixes chime and enhance its contact with digestive enzymes and enterocytes b Segmentation c Haustration Mass movement that occurs in the colon to move contents contract very sluggishly 5 What are the components of gastric juice What role does each play Hydrochloric Acid denatures proteins and activates pepsin Pepsin enzyme to digest protein Gastric Lipase enzyme that digests fats Intrinsic Factor protein to absorb vitamin B12 6 What is the function of bicarbonate secreted in the stomach and pancreas individually Bicarbonate neutralizes acid in the stomach Bicarbonate neutralizes chyme in the pancreas 7 What is a bolus and what is chyme Bolus the mass of food chewed and moistened in the mouth Chyme liquid product of mechanical and chemical digestion in the stomach 8 What are the 3 sections of the small intestine Duodenum Jejunum Ileum 9 What are the major functions of the large intestine To store undigested food material And absorb Water Short chain fatty acids Electrolytes 10 Review the digestive enzymes and hormones of the gastrointestinal tract GIT and their function a Hormones Gastrin CCK Grehlin Secretin GIP Gastrin Secretin Grehlin CCK Production Site Stomach Target Organ Stomach Actions stimulates secretion of HCl and pepsinogen stimulates gastric motility promotes proliferation of gastric mucosal cells Production Site Small Intestine Duodenum Target Organs Pancreas and Stomach Actions Pancreas stimulates secretion of pancreatic bicarbonate Stomach decreases gastric motility Production Site Stomach Plays a role in stimulating eating promoting the activity and motility of the GI tract regulating carbohydrate metabolism Production Site Small Intestine Duodenum Jejunum Target Organs Pancreas Gallbladder Stomach Actions Pancreas stimulates secretion of pancreatic digestive enzymes Gallbladder stimulates gallbladder contraction signals to release bile Stomach slows gastric emptying GIP Gastric Inhibitory Peptide Production Site Small Intestine Target Organs Stomach and Pancreas Actions Stomach Inhibits gastric acid secretion and slows gastric emptying Pancreas Stimulates insulin release b Digestive Enyzmes Know all enzymes secreted in mouth stomach and small intestine and Salivary Amylase Digests carbohydrates produced in the mouth site of action in the mouth Pepsin Digests proteins Gastric Lipase Digests Fats all produced in the stomach site of action in the stomach Proteases Digests proteins Elastase Digests fiborous proteins Pancreatic Lipase Digests Fats Cholesterol Esterase Digests cholesterol Pancreatic Amylase Digests carbohydrates All produced in the pancreas Site of action Small intestine know what those enzymes digest Mouth Stomach Pancreas Small Intestine Carboxypeptidase Aminopeptidase Dipeptidase Digest Proteins Lipase Digests Lipids Sucrase Maltase Lactase Digests the simple carbohydrates sucrose maltose and lactose 11 What are accessory organs in digestion List 3 accessory organs and their role in digestion All three produce store and secrete enzymes and other chemicals that are involved in digestion Stores Bile Bile A greenish fluid produced by the liver that emulsifies lipids manufactures holds and secretes digestive enzymes stores enzymes in the inactive form which is why as seen in 10 the site of action is not the pancreas but the small intestine produces the hormones insulin and glucagon to regulate blood glucose secretes bicarbonate to neutralize chyme synthesizes chemicals for metabolism such as Bile for the emulsification of fat receives the products of digestion 1 Gallbladder 2 Pancreas 3 Liver releases glucose from glycogen storages stores vitamins manufactures blood proteins filters the blood 12 Describe the anatomy of the small intestine The lining of the small intestine is heavily folded resulting in the increases surface area for the absorption of nutrients The folds are covered with villi finger like projections The cells on the surface of the villi are called enterocytes Enterocytes end in hair like projections called microvilli that together form the brush border through which nutrients are absorbed Each villus contains capillaries and a lacteal for picking up nutrients absorbed through the enterocytes and transporting them throughout the body 13 What are the 4 types of absorption in the small intestine Nutrients just pass through the enterocytes and into the blood stream without the use of a carrier or energy water Requires a carrier protein to pass through Requires energy and a carrier protein to transport nutrients Active transport by which a small amount of intestinal contents is engulfed by the enterocyte s cell membrane and incorporated into the cell 1 Passive Diffusion 2 Facilitated Diffusion 3 Active Transport 4 Endocytosis 1 What is the difference between simple and complex carbohydrates Chapter 4 Study Guide Contain one sugar molecule Ex Glucose Fructose Galactose a Monosaccharides vs disaccharides Monosaccharide Disaccharide Contain two sugar molecules Ex Lactose Maltose and Sucrose Lactose Glucose Galactose Maltose Glucose Glucose Sucrose Glucose Fructose b
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