CH-11 Ingestive Behavior – Foundations of Behavioral Neuroscience : Exam Guide

Chapter 11: Ingestive Behavior 11.1 Multiple Choice 1) Carrie was underweight as a baby, and in grade school she began to A) engage in self-mutilation. B) overeat and gain weight. C) show depression. D) view herself as underweight. E) show fits of violence. Answer: B Rationale: Carrie was underweight as a baby, and in grade school she began to overeat and gain weight. 2) The process of ________ regulates the fluid that bathes our cells. A) positive feedback B) homeostasis C) hemostasis D) hypovolemia E) osmogenesis Answer: B 3) The optimal value of the system variable in a homeostatic system is termed the A) correctional mechanism. B) thermostat. C) set point. D) detector. E) homeostatic variable. Answer: C 4) Which of the following is an essential element of all regulatory systems? A) satiety mechanisms B) positive feedback C) anticipatory satiety D) negative feedback E) ingestive mechanisms Answer: D 5) Which of the following is the systems variable in a regulatory system such as a cooking oven? A) the timer mechanism B) the thermostat within the oven C) the oven light D) the air temperature in the oven E) the highest temperature achieved by the oven Answer: D Rationale: The systems variable in a regulatory system such as a cooking oven the air temperature in the oven. 6) Because there can be a long delay between ingestion and the digestion/assimilation of a substance into a system, a ________ is needed to help regulate ingestive behavior. A) satiety mechanism B) set point C) positive feedback loop D) negative feedback factor E) correctional mechanism Answer: A Rationale: Satiety mechanisms help to regulate systems in which there is a delay between ingestion and absorption of a needed substance. 7) About two-thirds of the body's water is contained within the ________ fluid. A) intravascular B) intracellular C) extracellular D) interstitial E) trans vascular Answer: B Rationale: About two-thirds of the body's water is contained within the intracelular fluid. 8) The term ______ means “standing between.” A) extracellular B) cerebrospinal. C) interstitial. D) cytoplasmic. E) intravascular Answer: C 9) The ______ and _____ fluid compartments must be regulated within precise limits. A) trans vascular; interstitial B) intracellular; cerebrospinal C) extracellular; intracellular D) intravascular; intracellular E) interstitial; intracellular Answer: D 10) An aqueous solution whose solute concentration is less than that of the intracellular fluid is termed A) cytoplasmic. B) isotonic. C) hypovolemic. D) hypertonic. E) hypotonic. Answer: E 11) The volume of blood in the body must be regulated because A) reduced blood volume causes water to move out of cells. B) reduced blood volume can cause water to move into cells. C) low blood volume can lead to better pumping action of the heart. D) low blood volume can lead to heart failure. E) high blood pressure can lead to better pumping action of the heart. Answer: D Rationale: The volume of blood in the body must be regulated because low blood volume can lead to heart failure. 12) To maintain proper fluid balance, the body contains two sets of receptors: one measures volume of the ________, and the other records the volume of the ________. A) cerebrospinal fluid; cells B) extracellular fluid; cells C) blood; cells D) interstitial fluid; intravascular compartment E) sodium ions; blood Answer: C Rationale: To maintain proper fluid balance, the body contains two sets of receptors: one measures volume of the blood, and the other records the volume of the cells. 13) ________ thirst refers to drinking provoked by loss of blood plasma. A) Osmometric B) Volumetric C) Extravascular D) Intravascular E) Transvascular Answer: B 14) Osmoreceptors are specialized neurons that detect A) changes in solute concentration of the interstitial fluid. B) osmotic pressure within the blood plasma. C) angiotensin concentration in the blood. D) the concentration of renin within the blood. E) blood plasma solute concentration. Answer: A 15) Which of the following is a strong stimulus for producing osmometric thirst? A) evaporation from the lungs during the winter months B) vomiting during illness C) loss of blood after an automobile trauma D) ingestion of a bag of salted potato chips E) infusion of blood into the vascular system Answer: D Rationale: Ingestion of a large bag of salted potato chips is a strong stimulus for producing osmometric thirst 16) Water loss from the body through evaporation would most likely result in A) loss of salt from the plasma. B) a decreased concentration of solute within the interstitial fluid. C) movement of water out of the cells. D) a gain of interstitial fluid. E) hypovolemic thirst but not osmometric thirst. Answer: C Rationale: Water loss from the body through evaporation would most likely result in movement of water out of the cells. 17) Research by Egan and others has suggested that osmoreceptors are located within the A) amygdala. B) medial hypothalamus. C) cerebral aqueduct. D) medial orbitofrontal cortex. E) anteroventral tip of the third ventricle. Answer: E Rationale: Research by Egan and others has suggested that osmoreceptors are located within the anteroventral tip of the third ventricle. 18) Which of the following is a potent stimulus for producing pure hypovolemia, but not osmometric thirst? A) loss of fluid volume from brain cells B) ingestion of a large meal C) loss of blood after an automobile trauma D) ingestion of a bag of salted potato chips E) evaporation from the skin. Answer: C Rationale: Loss of blood after an automobile trauma is a potent stimulus for producing pure hypovolemia, but not osmometric thirst. 19) Organisms can achieve water balance via consumption of ________ and ________. A) water; sodium chloride B) sodium chloride; carbohydrates C) water; minerals D) fats; carbohydrates E) proteins; water Answer: A 20) A key stimulus that evokes hypovolemic thirst is A) lack of renin in the blood. B) loss of intracellular water. C) increased sodium within the preoptic region. D) reduced blood flow to the kidneys. E) increased blood flow to the kidneys. Answer: D Rationale: A key stimulus that evokes hypovolemic thirst is reduced blood flow to the kidneys. 21) Which of the following is a known physiological effect of angiotensin II? A) consumption of glucose B) release of water and salt into the urine C) decreased blood pressure D) consumption of salt E) increased blood flow within the skin Answer: D Rationale: Administration of angiotensin II results in the consumption of salt. 22) Angiotensin II stimulates drinking by acting on cells within the A) kidney. B) nucleus of the solitary tract. C) lateral hypothalamus. D) subfornical organ. E) atria of the heart. Answer: D 23) The ______ is a neural region in front of the anterior commissure that is sensitive to information from the subfornical organ and that communicates with motor neurons that control drinking. A) lateral hypothalamus B) median preoptic nucleus C) median amygdala D) nucleus accumbens E) fornix Answer: B 24) ________ is secreted by pancreatic cells in response to ________. A) Amylin; the entry of fat into the duodenum B) Glucagon; a rise in blood glucose C) Insulin; a fall in blood glucose D) Glucagon; a fall in blood glucose E) Leptin; a fall in blood glucose Answer: D 25) The carbohydrate reservoir in the liver is primarily reserved for A) the central nervous system. B) the activation of nonshivering thermogenesis. C) the muscles. D) the liver. E) formation of amino acid neurotransmitters. Answer: A Rationale: The carbohydrate reservoir in the liver is primarily reserved for the central nervous system. 26) Our short-term fuel reservoir is contained in cells located within the A) adipose tissue. B) stomach. C) liver and muscles. D) pancreas. E) duodenum. Answer: C 27) Which of the following helps to explain why it is a bad idea to skip breakfast? A) Skipping breakfast releases leptin, which activates hunger neurons in brain. B) Fuel absorption is faster in the morning than in the afternoon. C) The minerals eaten in a typical breakfast are important for energy metabolism. D) The liver carbohydrate reserve can only be refilled during the morning. E) The liver holds a limited amount of glucose for use by the brain, and this supply can be depleted after an overnight fast. Answer: E Rationale: The fact that the liver holds a limited amount of glucose for use by the brain, and this supply can be depleted after an overnight fast is why skipping breakfast is a bad idea. 28) Our long-term fuel reservoir is filled with ________ and is located in ________. A) triglycerides; the liver B) glycogen; the brain C) triglycerides; fat cells D) insulin; the pancreas E) glycogen; the liver Answer: C 29) A unique feature of the _____ is that these cells do NOT require insulin in order to transport glucose across the cell membrane. A) liver cells B) cells of the brain C) muscle cells D) pancreatic cells E) cardiac cells Answer: B Rationale: A unique feature of the cells of the brain is that these cells do NOT require insulin in order to transport glucose across the cell membrane. 30) ________ is the key factor that controls the absorptive phase of metabolism. A) CCK B) Leptin C) Glucagon D) Insulin E) Glycerol Answer: D 31) An example of an environmental stimulus that could trigger eating is A) the smell of dirt. B) the sight of a Home Depot sign.. C) a broken clock.. D) the sight of a plate of food. E) the sound of traffic noise. Answer: D Rationale: An example of an environmental stimulus that could trigger eating is the sight of a plate of food. 32) Eating is initiated by secretion of ________ from the ________. A) insulin; stomach B) ghrelin; stomach C) insulin; hypothalamus D) ghrelin; hypothalamus E) CCK; hypothalamus Answer: B 33) Ghrelin is a neuropeptide secreted from the ________ that functions to ________. A) stomach; initiate eating B) pancreas; inhibit eating C) liver; suppress insulin secretion D) duodenum; control CCK levels in the plasma E) PVN; inhibit eating Answer: A Rationale: Ghrelin is a neuropeptide secreted from the gut that functions to initiate feeding. 34) Which of the following is true of ghrelin? A) Fasting reduces blood levels of ghrelin. B) Blood levels of ghrelin are increased after a meal. C) Infusion of ghrelin into the brain stimulates food intake. D) Infusion of ghrelin into the gut suppresses the secretion of glucagon. E) Ghrelin knockout mice are anorexic and lose body weight. Answer: C 35) Injection of insulin into the body results in A) eating. B) the secretion of glucagon. C) conditioned satiety. D) lipoprivation. E) nausea and vomiting. Answer: A 36) Match up the correct behavior with its antecedent condition. A) insulin; sexual behavior B) insulin; drinking C) methyl palmoxirate; drinking D) insulin; eating E) 2-DG; drinking Answer: D 37) Which of the following is correct regarding the role of the liver in the regulation of eating? A) Activation of lipid metabolism within the liver leads to eating. B) Cutting the vagal afferent outputs of the liver does not alter the effects of hepatic portal 2-DG on eating. C) Glucoprivation within the liver after 2-DG leads to eating. D) The brain receives hunger signals from the liver via the pudendal nerve. E) The liver receives signals from the brain to release insulin after a meal. Answer: C Rationale: Glucoprivation within the liver after 2-DG leads to eating. 38) Detectors for glucose are located within the A) liver. B) duodenum. C) gut. D) cerebellum. E) stomach. Answer: A 39) The detectors for fatty acids are located within the A) liver. B) duodenum. C) gut. D) brain tissue surrounding the fourth ventricle. E) pancreas. Answer: A 40) Which of the following is true of the signals that stop a meal? A) There are at least two sources of satiety signals that act to stop a meal. B) Short-term satiety signals are generated from adipose tissue. C) Leptin represents a short-term satiety signal. D) Long-term satiety signals are generated by the consequences of eating a meal. E) There is one satiety signal. Answer: A Rationale: Short-term satiety signals are generated from adipose tissue. 41) Experiments by Deutsch and colleagues allowed rats to eat until they were satiated and then withdrew a few milliliters of diet from their stomach using an implanted catheter. After the withdrawal, the rats A) ate until they became obese. B) reported no hunger pangs. C) showed evidence of continued short-term satiety. D) experienced periodic feelings of hunger. E) ate enough food to replace that withdrawn from the stomach. Answer: E Rationale: Experiments by Deutsch and colleagues allowed rats to eat until they were satiated and then withdrew a few milliliters of diet from their stomach using an implanted catheter. After the withdrawal, the rats ate enough food to replace that withdrawn from the stomach. 42) Which situation below would be expected to produce the largest degree of stomach fullness? A) placing a small volume of food directly into the stomach B) swallowing a mouthful of food that then exits via the esophagus C) swallowing a mouthful of food that is restricted to the stomach D) chewing a bite of food and then spitting it out E) distension of the stomach by an inflatable bag, in combination with infusion of nutrients directly into the duodenum Answer: E Rationale: The largest degree of stomach fullness would be produced by distension of the stomach by an inflatable bag, in combination with infusion of nutrients directly into the duodenum. 43) All of the following statements about cholecystokinin (CCK) are true EXCEPT that A) it inhibits gastric contractions. B) the site of action for CCK is directly on neurons of the ventromedial hypothalamus. C) it stimulates contraction of the gallbladder and pylorus. D) it inhibits eating. E) the blood level of CCK is related to the fat content of a meal. Answer: B Rationale: CCK does not act directly on neurons of the ventromedial hypothalamus to inhibit eating. 44) Which of the following indicates the importance of peripheral nutrient receptors, located in the liver, in satiety? A) Glucose infusions into the hepatic portal vein inhibit eating. B) Insulin can initiate or inhibit eating. C) Fructose infusions into the hepatic portal vein inhibit eating. D) Nutrient receptors are located in the brain tissue surrounding the lateral ventricle. E) Infusion of 2-DG into the lateral ventricle stimulates eating. Answer: C Rationale: The fact that fructose infusions into the hepatic portal vein inhibit eating indicates the importance of peripheral nutrient receptors, located in the liver, in satiety. 45) In the experiment by Tordoff and Friedman (1988), reduced eating in a hungry rat was noted after A) infusions of glucose or fructose into the hepatic portal vein. B) removal of nutrients from the stomach. C) the investigators cut the hepatic branch of the vagus nerve. D) placement of nutrients directly into the stomach. E) 2-DG was injected into the hepatic portal vein. Answer: A Rationale: In the experiment by Tordoff and Friedman (1988), reduced eating in a hungry rat was noted after infusions of glucose or fructose into the hepatic portal vein. 46) Insulin in the blood appears to be interpreted by the brain as A) a hunger signal. B) an indicator of the entry of fat into the duodenum. C) an indicator that the body is in the absorptive phase of metabolism. D) a satiety signal. E) a signal that the body requires food. Answer: D Rationale: Insulin in the blood appears to be interpreted by the brain as a satiety signal. 47) Mice that lack insulin receptors in the ________ are prone to ________. A) brain; enhanced thermogenesis B) brain; altered metabolism C) brain; develop obesity D) gut; reject a high-fat diet E) gut; develop obesity Answer: C Rationale: Mice that lack insulin receptors in the brain are prone to develop obesity. 48) The ob mouse becomes obese because it lacks the gene that normally produces A) CCK. B) leptin. C) insulin. D) NPY. E) glutamate. Answer: B 49) Which of the following is true of the ob mouse? A) The ob mouse develops obesity at weaning. B) The ob mouse has a fast metabolism. C) Fat cells in the ob mouse fail to produce leptin. D) The obesity of the ob mouse can be reversed by daily injections of insulin.. E) The ob mouse fails to secrete ghrelin. Answer: C 50) Which of the following is correct regarding leptin? A) Ob mice lack the gene that codes for ghrelin. B) Leptin produces a decrease in metabolic rate. C) Leptin stimulates eating. D) Leptin levels in the blood are proportional to the fat stores of the body. E) leptin release is stimulated by the entry of food into the duodenum. Answer: D Rationale: Leptin levels in the blood are proportional to the fat stores of the body. 51) Damage to the ________ abolishes glucoprovic and lipoprivic eating. A) preoptic hypothalamus B) nucleus accumbens C) nucleus of the solitary tract D) ventromedial hypothalamus E) fornix Answer: C Rationale: Damage to the nucleus of the solitary tract abolishes glucoprovic and lipoprivic eating. 52) Studies using decerebrate rats indicate that A) the circuits controlling ingestion lie forward to the brain stem. B) CCK acts within the frontal cortex to stimulate eating. C) the brain stem contains circuits that allow a rat to chew and to swallow. D) decerebrate rats are unable to chew, to swallow, or to distinguish tastes. E) feeding circuits are contained within the forebrain. Answer: C 53) Electrolytic lesions of the ventromedial hypothalamus ________ whereas electrical stimulation ________. A) impair sexual behavior; elicits repetitive bouts of copulation B) inhibit eating; produces overeating C) elicit repetitive bouts of copulation; impairs sexual behavior D) produce overeating to obesity; inhibits eating E) activate thermogenesis; induces shivering Answer: D 54) Electrical stimulation of the lateral hypothalamus A) produces eating and drinking. B) inhibits food intake. C) produces sham feeding. D) elicits repetitive chewing movements. E) is an intensely aversive stimulus. Answer: A 55) Which of the following is correct regarding the lateral hypothalamus? A) Electrical stimulation of the lateral hypothalamus stimulates eating. B) Reduced eating is noted after injection of lipid into the lateral hypothalamus. C) Substance P containing neurons from the arcuate nucleus synapse onto orexin neurons within the lateral hypothalamus. D) The lateral hypothalamus can alter sexual motivation. E) Obesity is the result of damage to the lateral hypothalamus. Answer: A 56) Which terms are synonymous? A) orexins; hypocretins B) NPY; CCK C) adrenaline; noradrenaline D) insulin; glucagon E) satiety; hunger Answer: A Rationale: The term orexin is synonymous with the term hypocretin 57) Which pair of peptides contained within the lateral hypothalamus is thought to increase eating? A) insulin and CCK B) serotonin and CCK C) NPY and orexin D) orexin and melanin-concentrating hormone E) CCK and ghrelin Answer: D 58) The effects of NPY on eating are due to activation of ________ localized within the ________. A) MCH neurons; lateral hypothalamus B) glutamate receptors; lateral hypothalamus C) NMDA receptors; amygdala D) alpha-adrenergic receptors; paraventricular hypothalamus E) leptin; liver Answer: A 59) Which of the following strongly suggests that the actions of ghrelin on food intake involve NPY? A) Ghrelin released from the stomach strongly inhibits NPY release in the hypothalamus. B) Ghrelin cells in the stomach contain NPY receptors. C) NPY levels are constant across the day-night cycle. D) Ghrelin receptors are located on NPY neurons. E) NPY strongly inhibits the capacity of ghrelin to suppress drinking. Answer: D Rationale: The fact that ghrelin receptors are located on NPY neurons suggests that the actions of ghrelin on food intake involve NPY. 60) A key effect of ghrelin that results in the stimulation of eating is to A) cause the stomach to release less ghrelin. B) activate CCK receptors in the brain. C) activate NPY neurons within the hypothalamus. D) decrease the release of NPY in the hypothalamus. E) increase the entry of insulin into the brain. Answer: C 61) Electrical stimulation of the LH is to electrical stimulation of the VMH as A) insulin is to glucagon. B) α-MSH is to agouti-related protein. C) CART is to NPY. D) agouti-related protein is to α-MSH. E) CCK is to ghrelin. Answer: D Rationale: Electrical stimulation of the LH is to electrical stimulation of the VMH as agouti-related protein is to α-MSH. 62) Which of the following would be useful for the treatment of poor appetite in a cancer patient? A) a serotonergic agonist B) an endocannabinoid agonist C) a drug that activates CART receptors D) an NPY antagonist E) an endocannabinoid antagonist Answer: B 63) A key effect of leptin that results in the inhibition of eating is to A) increase the entry of insulin into the brain. B) activate CCK receptors in the brain. C) inactivate receptors that control the release of hypothalamic NPY and AGRP. D) decrease the release of NPY in the hypothalamus. E) cause the stomach to release more ghrelin. Answer: C Rationale: A key effect of leptin that results in the inhibition of eating is to inactivate receptors that control the release of hypothalamic NPY and AGRP. 64) The MC-4R receptor is activated by ________ and inhibited by ________. A) insulin; glucagon B) agouti-related protein; NPY C) α-MSH; agouti-related protein D) nicotine; amphetamine E) α-MSH; CCK Answer: C 65) Which of the following is true regarding CART? A) Infusion of an antibody to CART decreases feeding. B) CART is a peptide localized within the area postrema. C) CART inhibits eating. D) CART is excitatory for MCH/orexin neurons. E) CART is the precursor molecule for the synthesis of CCK. Answer: C 66) Which pair below are classed as anorexigens? A) NPY and insulin B) ghrelin and CART C) CCK and ghrelin D) CART and α-MSH E) NPY and AGRP Answer: D Rationale: CART and α-MSH are classified as anorexigens. 67) Which pair below represents orexigens? A) CCK and ghrelin B) ghrelin and CART C) NPY and insulin D) CART and α-MSH E) NPY and AGRP Answer: E Rationale: NPY and AGRP are classified as orexigens. 68) The ability of leptin to inhibit eating can be viewed as a dual action in the brain that involves the activation of ________ and the inhibition of ________. A) CART/α-MSH neurons; NPY/AGRP neurons B) CCK receptors; serotonin neurons C) ghrelin cells in the stomach; CART/α-MSH neurons D) insulin receptors; CCK receptors E) GABA neurons; MCH/orexin neurons Answer: A Rationale: The ability of leptin to inhibit eating can be viewed as a dual action in the brain that involves the activation of CART/α-MSH neurons and the inhibition of NPY/AGRP neurons. 69) A serious health hazard that accompanies obesity is A) dizziness due to low blood pressure B) acne. C) cardiovascular disease. D) most forms of cancer. E) arthritis. Answer: C 70) Which of the following is not considered to be a key factor that contributes to obesity? A) the generous portions provided by fast-food restaurants B) learning to eat all that is placed on your plate C) the fact that we require more calories as we get older D) innate aberrations of metabolism E) the fact that we require fewer calories as we get older Answer: C Rationale: Humans do not require more calories as they grow older. 71) Which of the following is considered to be a key factor that contributes to obesity? A) too much physical work in our daily lives B) learning to eat all that is placed on your plate C) some persons are inefficient at storing ingested calories as fat D) the increasingly smaller portions provided by fast-food restaurants E) rapid genetic mutations. Answer: B Rationale: A key factor that contributes to obesity is eating everything that is provided to us on a plate. 72) Which of the following supports the notion that heredity contributes to differences in body weight? A) Pima Indians in the US and Mexico share the same genes, but only those persons who live in a particular environment develop obesity. B) Several forms of human obesity involve a deficit in ghrelin production, which can be treated by ghrelin injection. C) Twin studies indicate that genes account for 25 percent of the variability in body fat accumulated when people are fed a high-fat diet. D) Twin studies indicate that genes account for little of the variability in body fat accumulated when people are fed a high-fat diet. E) Adoption studies fail to show a role for heredity in obesity. Answer: A Rationale: The fact that Pima Indians in the US and Mexico share the same genes, but only those persons who live in a particular environment develop obesity supports the notion that heredity contributes to differences in body weight. 73) Which of the following is used by the text author to explain why people exhibit differences in metabolic efficiency? A) Metabolic efficiency is advantageous for surviving in an environment where calories are hard to obtain. B) Metabolic efficiency results in obesity but does not result in health disorder. C) The excessive accumulation of fat is a social proxy for wealth. D) Obesity allowed hunter-gatherers to forage for long periods of time. E) Genetic mutations involving metabolic efficiency are quite common. Answer: A Rationale: Metabolic efficiency is advantageous for surviving in an environment where calories are hard to obtain. 74) Which of the following is true of leptin? A) Leptin is a product of protein metabolism. B) Leptin levels are decreased during overeating and obesity. C) Mutations of the leptin gene are the most common cause of obesity. D) Plasma leptin levels are related to body fat content only in obese persons. E) Few cases of human obesity are related to a mutation of the gene for leptin and leptin receptors. Answer: E Rationale: Sadly, few cases of human obesity are related to a mutation of the gene for leptin and leptin receptors. 75) A key factor for the success of the RYGB procedure for the treatment of obesity is that A) the procedure increases the rate of entry of insulin into the brain. B) it disrupts the secretion of CCK. C) it increases the activity of NPY neurons. D) it disrupts the secretion of ghrelin. E) it decreases the secretion of leptin from fat cells. Answer: D Rationale: A key factor for the success of the RYGB procedure for the treatment of obesity is that it disrupts the secretion of ghrelin. 76) A drug that would treat obesity might be expected to A) promote the activity of uncoupling protein in skeletal muscle. B) suppress metabolic rate. C) impair the activity of uncoupling protein in skeletal muscle. D) promote the development of a "thrifty" phenotype. E) block the transport of leptin into the brain. Answer: A Rationale: A drug that would treat obesity might be expected to promote the activity of uncoupling protein in skeletal muscle. 77) Which of the following are important determinants of weight in adult humans? A) the amount of protein consumed each day B) the hours of TV viewed per day C) the amount of physical exercise a person gets during their leisure time D) the amount of CCK in the blood stream of a person E) whether the person has a family history of anorexia. Answer: C Rationale: An important determinants of weight in adult humans is the amount of physical exercise a person gets during their leisure time 78) Drugs such as fenfluramine that were used to treat obesity exerted an inhibition of appetite by A) blocking serotonin receptor activity in the PVN. B) causing the release of NPY from cells in the arcuate. C) activating CART receptors. D) altering serotonin activity in the PVN. E) acting as a serotonin agonist in the brain. Answer: E Rationale: Drugs such as fenfluramine that were used to treat obesity exerted an inhibition of appetite by acting as a serotonin agonist in the brain. 79) Which of the following would be a useful treatment for obesity? A) a drug that activates leptin, CCK, CART, or MC4 receptors B) a drug that activates NPY or ghrelin receptors C) a drug that promotes fat absorption D) fenfluramine E) C and D given in combination. Answer: A Rationale: A drug that activates leptin, CCK, CART, or MC4 receptors would be a useful treatment for obesity. 80) The serotonin agonist fluoxetine may be useful for the treatment of A) schizophrenia. B) bulimia. C) anorexia. D) mania. E) autistic disorder. Answer: B Rationale: The serotonin agonist fluoxetine may be useful for the treatment of bulimia. 81) Administration of the CB1 receptor antagonist ________ may be useful in the treatment of ________. A) nisoxetine; anorexia nervosa B) orlistat; anorexia nervosa C) rimonabant; obesity D) fenfluramine; obesity and bulimia E) rimonabant; anorexia nervosa Answer: C Rationale: Administration of the CB1 receptor antagonist rimonabant may be useful in the treatment of obesity. 82) The distinction between bulimia and anorexia nervosa is that A) anorexia is a metabolic disorder. B) anorexia can be associated with weight gain. C) bulimia reflects an obsession with weight loss. D) anorexia nervosa involves weight loss, while bulimia involves binging. E) bulimia is a metabolic disorder. Answer: D 83) A key aspect of anorexia nervosa is A) an intense fear of obesity. B) the binging and subsequent purging of food. C) a lack of exercise. D) an overstimulation of NPY and ghrelin receptors. E) a defect in insulin metabolism. Answer: A Rationale: A key aspect of anorexia nervosa is an intense fear of obesity. 84) The incidence of anorexia nervosa is ________, while that of bulimia is ________. A) 0.1–4.0 percent; 3–6 percent B) 0.5–2.0 percent; 1–3 percent C) 1–3 percent; 0.5–2.0 percent D) 3–6 percent; 0.1–4.0 percent E) 4–6 percent; 8–15 percent Answer: B 85) The obsession with food noted in anorexia may be related to A) elevated levels of CCK in the brain. B) a deficiency of NPY in the brain. C) elevated levels of NPY in the brain. D) excessive consumption of protein, which is highly satiating. E) a failure of menstruation brought on by excessive exercise. Answer: C Rationale: The obsession with food noted in anorexia may be related to elevated levels of NPY in the brain. 86) Which of the following drugs may be useful for the treatment of anorexia nervosa? A) THC B) fluoxetine C) L-DOPA D) insulin E) No drug is available for the treatment of anorexia nervosa. Answer: E Rationale: No drug is currently available for the treatment of anorexia nervosa. 87) The overeating noted in patients such as Carrie reflects A) increased hunger. B) degeneration of the prefrontal cortex. C) defective brain satiety mechanisms. D) a genetic defect on chromosome 2. E) low plasma ghrelin levels. Answer: C Rationale: The overeating noted in patients such as Carrie reflects defective brain satiety mechanism. 11.2 True-False 1) A system variable is a variable that is controlled by a regulatory mechanism. Answer: True 2) Interstitial fluid is normally hypertonic with respect to the intracellular fluid. Answer: False 3) Carlson defines "thirst" as our tendency to seek out water and ingest it. Answer: True 4) Eating a salty meal induces volumetric thirst. Answer: False 5) Osmosis is the movement of water through a semipermeable membrane, from a region of low solute concentration to one of high solute concentration. Answer: True 6) Loss of blood, vomiting, or diarrhea can result in volumetric thirst. Answer: True 7) Injections of hypertonic saline directly into the cerebral aqueduct produce drinking. Answer: False 8) A craving for sodium chloride is called a salt appetite. Answer: True 9) Long-term energy stores consist of triglycerides stored in adipose tissues. Answer: True 10) The primary physiological signal for hunger is likely a decrease in glucose or fatty acid levels in the blood. Answer: True 11) Insulin may serve as a satiety signal in brain. Answer: True 12) Cholecystokinin inhibits food intake, whereas ghrelin stimulates food intake. Answer: True 13) Leptin affects food intake, but not metabolism. Answer: False 14) Lesions of the lateral hypothalamus produce overeating and obesity in laboratory animals. Answer: False 15) NPY stimulates eating. Answer: True 16) Cannabinoid agonists stimulate eating. Answer: True 17) CART and α-MSH are orexigenic peptides. Answer: False 18) Reduced levels of leptin in the brain or fewer brain leptin receptors may contribute to obesity. Answer: True 19) A troubling side effect of the RYGB gastric procedure in the treatment of obesity is an elevated risk for death. Answer: True 20) Individuals with anorexia nervosa lose all interest in food. Answer: False 21) Fluoxetine is useful for the treatment of bulimia, but not anorexia nervosa. Answer: True 11.3 Short-Answer Essay 1) Describe the four essential components of a regulatory system. Answer: The system variable is the characteristic to be regulated; the set point is the optimal value of the system variable; a detector monitors the system value; and a correctional mechanism restores the system variable to the set point value. 2) Describe the intracellular and extracellular fluid compartments of the body. Answer: The fluid contained within the cytoplasm of cells comprises the intracellular compartment. In contrast, the extracellular fluid includes the intravascular fluid (blood plasma), the cerebrospinal fluid, and the interstitial fluid (located between cells). The intracellular compartment comprises two-thirds of the body's water. 3) Describe the stimuli and receptors that induce volumetric thirst. Answer: The detectors are located within the kidney – these are sensitive to blood flow. Upon activation, these cells secrete renin, which starts a sequence of catalytic events relating to angiotensin, which in turn initiates drinking and consumption of salt. Evaporation will reduce the plasma compartment, leading to volumetric thirst. Other hypovolemic stimuli are loss of blood, vomiting, or diarrhea. 4) Compare and contrast the short- and long-term energy stores of the body. Answer: Liver cells convert glucose to glycogen, which is then stored within the liver and the muscles. This short-term store is used to fuel the brain and is rapidly depleted. Glucagon secretion catalyzes the conversion of glycogen to glucose. The long-term energy store is within fat cells and is composed of triglycerides. Glycerol is a major product of triglyceride metabolism and is converted to glucose within the liver. 5) Describe the role of ghrelin in the control of eating. Answer: Ghrelin is released from the stomach when it and the duodenum are empty of food. Injection of ghrelin stimulates eating, while food intake suppresses ghrelin levels. 6) Describe the significance of cholecystokinin (CCK) for the regulation of eating. Answer: CCK is released into blood upon the entry of fats into the duodenum. CCK is thus in a position to provide a satiety cue to the brain. Injection of CCK reduces eating in the short-term. Obesity is noted in rats for which a genetic mutation impairs the production of CCK receptors. 7) Explain why it is believed that the lateral hypothalamus (LH) plays a key role in the control of eating. Answer: Ablation of the LH produces aphagia and adipsia, which reflects cell damage rather than damage to axons of passage. Electrical stimulation of the LH elicits eating. Cells within the LH secrete MCH as well as orexin, two neuropeptides that induce eating. 8) Explain why metabolic efficiency is a key factor in obesity. Answer: Animals vary in their capacity to store ingested energy as fat. Some animals are very efficient in that ingested energy can be stored as fat for later use, e.g., during a famine. Other animals are less efficient and waste some portion of ingested energy (e.g., thermogenesis or activity); these animals are less likely to develop obesity in times of abundant food. 11.4 Essay 1) Describe the stimuli that produce osmometric thirst and cite evidence indicating the location of osmoreceptors in the brain. Answer: Cells must maintain a constant volume within the cell. Changes in solute concentration outside the cell will produce movements of water through the cell membrane. A decrease in solutes outside the cell will result in water moving into the cell, whereas an increase in solutes will draw water from the cell and lead to cell shrinkage. The latter will obtain if water is lost through evaporation or if the organism consumes a salty meal. Osmoreceptors are located in the brain; injection of hypertonic saline into the tissue just anterior to the third ventricle (AV3V) will induce drinking. 2) Compare and contrast the hormonal events that take place during the absorptive and fasting phases of metabolism. Answer: In the absorptive phase, the release of insulin promotes the entry of glucose into cells and into the short-term store as glycogen. As glucose is used for fuel, plasma levels decline and glucagon is secreted, which in turn enhances the conversion of glycogen to glucose. After the glycogen store is depleted, triglycerides are broken down from the long-term fat store forming glycerol, which the liver can use to create glucose. 3) Describe the role of the stomach and ghrelin in food intake and compare its importance in producing hunger and satiety. Answer: The stomach does play a role in satiety in that nutrient sensors are located within the stomach and that removal of a meal from the stomach during a period of satiety will result in the animal consuming sufficient food to replace the withdrawn food. 4) Describe the general neural framework for the control of eating in terms of feeding facilitory and feeding-inhibitory circuits. Answer: No one area is the final controller of eating. Sensory and motor information from the gut is sent to the brain stem, where basic feeding reflexes are controlled. Forebrain circuits arising from the lateral hypothalamus can act via MCH and orexins to facilitate eating, and this region appears to be sensitive to the orexigenic effects of NPY. Cells within the arcuate nucleus secrete both NPY and agouti-related peptide (AGRP), which acts as an antagonist at MC-4R receptors that normally function to inhibit eating. Thus NPY and AGRP stimulate eating. A common finding is that a specific neuropeptide may exert dual actions: namely, facilitating actions in one pathway (e.g., MCH/orexin) and inhibiting activity in the other pathway (e.g., NPY/AGRP). Leptin can inhibit NPY activity and can activate cells that express CART. 5) Cite evidence from the human and rat literature which suggests that obesity is not caused merely by a weak will. Answer: The genetic literature suggests that there is a strong heritability factor for obesity. Although no simple genetic defect has been found for obesity, it is clear that there are important differences in metabolism that result in some persons easily gaining weight during periods of access to high energy diet, while others appear to be resistant to gaining weight. Finally, genetic mutations in feeding relevant pathways (e.g., leptin, MC-4R) in animals are routinely found to produce overeating and weight gain. Animals are not commonly thought of as having a weak will. Test Bank for Foundations of Behavioral Neuroscience Neil R. Carlson 9780205968091, 9780134639796, 9780205947997