Exam 2 Study Guide Hunger foods cues Appetite 1 Define hunger and appetite Which organ triggers feelings of hunger and satiation A physiological drive for food Can be satisfied by a variety of nonspecific A psychological desire to consume specific foods Aroused by environmental Hypothalamus Triggers feelings of Hunger or Satiation fullness Located above the pituitary gland and the brain stem in an area of the brain that Integrates signals from nerve cells chemical messengers hormones and the regulates involuntary activities types of food consumed 2 What effect do different macronutrients have on hunger What type of food has the highest satiation value Foods have differing effects on our feelings of Hunger Proteins High fat diets have a higher satiety value than high carbohydrate diets Bulky meals high in fiber and high in water distend the stomach and promote a sense of have the highest satiety value will feel satiated for longer satiety Solid foods are more filling than semisolid foods or Lipids 3 Define the processes of digestion absorption and elimination Large food molecules are broken down to smaller molecules mechanically Digestion chewing mouth and chemically enzymes Absorption Elimination body The process of taking these products through the Intestinal Wall Undigested portions of food and waste products are removed from the 4 Know the difference between peristalsis and segmentation The waves of squeezing and pushing contractions that move food chyme Peristalsis and feces into one direction through the length of the GI tract towards the esophagus to the stomach No digestion occurs Segmentation The rhythmic contraction of the circular muscles of the small intestine which squeezes chyme mixes it and enhances the digestion and absorption of nutrients from the chyme Advantage Peristalsis is smooth muscle of wave contractions move food in one direction along GI tract Segmentation smooth muscle back and forth contractions to mix and break food further down They both only work for mechanical digestion 5 Know the role of gastrin Gastrin glands to produce gastric juice A hormone secreted by stomach lining cells g cells that stimulates the gastric 6 Know the two different types of cells in gastric glands What is gastric juice and what is the role of each component of the gastric juice Gastric Glands Parietal Cells Secretes Lined with two important types of cells Chief Cells Secretes HCl Hydrochloric Acid It helps to keep the stomach interior very acidic low in ph killing any bacteria and or germs that may have entered the body with the food It is also extremely important for digestion because it starts to denature proteins which means it breaks the bonds that maintain their structure important for protein digestion A protein critical to the absorption of vitamin B12 Intrinsic factor Pepsinogen An inactive enzyme which HCl converts into the active enzyme pepsin It then begins the digestion of Proteins It also activates many other GI enzymes that contribute to digesting your food Gastric Lipase An enzyme responsible for lipid digestion breaks down fats An acidic liquid secreted within the stomach it contains hydrochloric Denatures Proteins and Activates Pepsin Gastric Juice acid pepsin and other compounds Hydrochloric Acid HCl Pepsin Gastric Lipase Intrinsic Factor Enzyme to Digest Protein Enzyme to Digest Fat Protein to Cleave Vitamin B12 for absorption in the GI Tract 7 Know the role of bicarbonate in stomach and small intestine Bicarbonate Stomach and Small Intestine released from the pancreas in response to the hormone secretin to neutralize the acidic chyme entering the duodenum from the stomach Neutralizes acidic chyme and decreases gastric mobility Neutralizes the Acid Regulates the pH It is 8 Know the enzymes produced in the gastrointestinal tract mouth stomach and pancreas that facilitate the digestion of carbohydrates fats and lipids Enzymes speed up bodily processes Complex chemicals that induce chemical changes in other substances to Digests Carbohydrates Salivary Amylase Mouth Pepsin Stomach Gastric Lipase Stomach Proteases Pancreas Elastase Pancreas Pancreatic Lipase Pancreas Cholesterol Esterase Pancreas Pancreatic Amylase Pancreas Digests Proteins Digests Lipids Digests Proteins Digests Fibrous proteins Digests Lipids Digests Cholesterol Digests Carbohydrates 9 List the key hormones involved in digestion and their actions Gastrin Stomach Stimulates secretion of HCl and pepsinogen inactive form of pepsin Stimulates gastric motility Promotes proliferation of gastric mucosal cells Targets the Stomach Secretin Small Intestine Duodenum Stimulates secretion of pancreatic bicarbonate which neutralizes acidic chyme Decreases gastric motility Targets the Pancreas and Stomach Cholecystokinin CCK Small Intestine Duodenum and Jejunum Stimulates secretion of pancreatic digestive enzymes Stimulates gallbladder contraction Slows gastric emptying Targets the Pancreas Gallbladder and Stomach gastric emptying Stimulates insulin release Targets the Stomach and Pancreas Gastric Inhibitory Peptide GIP Small Intestine Inhibits gastric acid secretion Slows 10 List the accessory organs that facilitate digestion and their roles Accessory Organs involved in digestion Food never enters the accessory organs directly Produce Store and Secrete enzymes and other chemicals that are Gallbladder Acts as a storage unit It stores Bile a greenish fluid produced by the liver CCK signals the gallbladder to release bile Bile emulsifies the lipids lipids are dispersed into smaller globules and become more accessible to digestive enzymes Manufactures Holds and Secretes Digestive Enzymes Pancreas Liver Stores enzymes in the inactive form Pancreatic Amylase digests carbohydrates Pancreatic Lipase digests fats Protease digests proteins It produces Insulin and Glucagon hormones to regulate blood glucose Bicarbonate is secreted to neutralize chyme It is one of the most important Organs in the body Synthesizes chemicals for metabolism Bile for emulsification of fats Receives the products of digestion via the Portal Vein Releases glucose from glycogen stores Stores Vitamins Manufactures Blood proteins Filters the blood removing wastes and toxins Gastrointestinal discomfort caused by certain foods that is not a result 11 Define food intolerance and food allergy Food Intolerance of an immune system reaction Food Allergy An allergic reaction to food caused by a reaction of the immune system 12 List the most common
View Full Document
Unlocking...