Deck 12: Ingestive Behavior

Question 1

Osmoreceptors are specialized neurons that detect

A) changes in solute concentration of the interstitial fluid around the cell.
B) the concentration of renin within the blood.
C) angiotensin concentration in blood.
D) osmotic pressure within the blood plasma.
E) blood plasma solute concentration.

Answer 1

A

Question 2

A potent stimulus for producing osmometric thirst involves

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) perspiration.

Answer 2

D

Question 3

Which fluid compartments must be precisely regulated within certain limits?

A) interstitial; intracellular
B) intracellular; cerebrospinal
C) extracellular; intracellular
D) intravascular; intracellular
E) transvascular; interstitial

Answer 3

D

Question 4

Nearly two-thirds of the body's water is contained within the ________ fluid.

A) interstitial
B) intracellular
C) extracellular
D) intravascular
E) transvascular

Question 5

Osmoreceptors change their firing rate in response to

A) the angiotensin concentration in blood.
B) the concentration of renin within the blood.
C) movement of water out of the osmoreceptor as the interstitial fluid becomes hypertonic.
D) reduced osmotic pressure within the blood plasma.
E) increased blood plasma volume.

Question 6

________ thirst refers to drinking provoked by the loss of blood plasma.

A) Intravascular
B) Volumetric
C) Extravascular
D) Osmometric
E) Transvascular

Question 7

To maintain proper fluid balance, the body contains two sets of receptors, one that measures the volume of the ________ and the other that records the volume of the ________.

A) cerebrospinal fluid; cells
B) extracellular fluid; cells
C) blood; cells
D) interstitial fluid; intravascular
E) sodium ions; blood

Question 8

If the detector in a physiological system were to fail, one would expect

A) that the regulatory system would work, but more slowly than usual.
B) that positive feedback would spin the system out of control.
C) no change in the system variable.
D) that the set point would increase.
E) that the system variable would not be constant.

Question 9

The term ________ refers to an aqueous solution whose solute concentration is less than that of the intracellular fluid.

A) hypertonic
B) isotonic
C) volumetric
D) cytoplasmic
E) hypotonic

Question 10

The optimal value of the system variable in a homeostatic system is termed the

A) thermostat.
B) detector.
C) set point.
D) correctional mechanism.
E) homeostatic variable.

Question 11

The primary symptom of Prader-Willi syndrome is a disturbance of

A) appetite.
B) sexual motivation.
C) thirst.
D) emotionality.
E) language.

Question 12

The term ________ refers to an aqueous solution whose solute concentration is greater than that of the intracellular fluid.

A) hypertonic
B) isotonic
C) volumetric
D) cytoplasmic
E) hypotonic

Question 13

A key reason why the volume of blood must be regulated within certain limits is that

A) reduced blood volume causes water to move out of cells.
B) reduced blood volume causes water to move into cells.
C) low blood volume leads to better pumping action in the heart.
D) low blood volume leads to heart failure.
E) high blood volume leads to low blood pressure.

Question 14

The opening vignette described the case of Carrie, who suffered from

A) appetite loss.
B) anorexia nervosa.
C) aphasia.
D) Prader-Willi syndrome.
E) aphagia.

Question 15

The process of ________ is involved in the regulation of the fluid that bathes our cells.

A) allostasis
B) homeostasis
C) hemostasis
D) negative feedback
E) hypovolemia

Question 16

The observation that animals will stop drinking long before the ingested water has been absorbed into the body suggests the existence of a(n) ________ that helps to regulate ingestive behavior.

A) satiety mechanism
B) feedback factor
C) positive feedback loop
D) set point
E) correctional mechanism

Question 17

Water loss from the body through evaporation results in

A) a loss of only interstitial fluid.
B) an increased concentration of solute within the interstitial fluid.
C) movement of water into the cells.
D) gain of water into the plasma.
E) loss of sodium from inside the cells.

Question 18

A correctional mechanism for low blood volume involves

A) the movement of urine into the blood through the kidney.
B) movement of water into cells.
C) a fasting pumping action in the heart.
D) a slower pumping action in the heart.
E) contracting the muscles of the arteries and veins.

Question 19

Which of the following is an example of 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

Question 20

The primary location of osmoreceptors within brain is within the

A) zone incerta.
B) area postrema.
C) amygdala
D) nucleus accumbens.
E) lamina terminalis.

Question 21

Zhang and colleagues report that ________ are mechanoreceptors that induce membrane ______.

A) volumetric receptors; spike discharge
B) osmoreceptors; depolarization
C) volumetric receptors; hyperpolarization
D) osmoreceptors; inhibition
E) osmoreceptors; hyperpolarization

Question 22

It is considered a bad idea to skip breakfast because

A) eating breakfast releases leptin, which activates brain cells.
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 carbohydrate reserve of the liver 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.

Question 23

________ is secreted by pancreatic cells in response to ________.

A) Insulin; a fall in blood glucose
B) Glucagon; a rise in blood glucose
C) Amylin; entry of fat into the duodenum
D) Glucagon; a fall in blood glucose
E) Leptin; a fall in blood glucose

Question 24

A drug that blocks the ________ would be expected to lower blood pressure.

A) synthesis of serotonin
B) formation of angiotensin II from angiotensin I
C) degradation of angiotensin II
D) osmometric system
E) secretion of ghrelin

Question 25

The only bodily cells that do not require insulin in order to transport glucose across the cell membranes are

A) liver cells.
B) cells of the brain.
C) muscle cells.
D) pancreatic cells.
E) adipose cells.

Question 26

The median preoptic nucleus

A) plays a role in feeding regulation in humans.
B) integrates most thirst-related stimuli.
C) is sensitive to neural signals generated by stomach stretch receptors.
D) is sensitive to information from the amygdala.
E) mediates the aversive aspect of intense thirst.

Question 27

The absorptive phase of metabolism is mostly controlled by release of

A) glucagon.
B) leptin.
C) CCK.
D) insulin.
E) glycerol.

Question 28

Brain damage in humans that involves the lamina terminalis

A) produces an intense feeling of thirst that cannot be satisfied.
B) impairs the capacity of a person to experience thirst after injection of hypertonic saline.
C) blocks the neural signals generated by the atrial baroreceptors.
D) leads to increased water consumption.
E) leads to overconsumption of salt.

Question 29

The fact that young Billy (described in the chapter anecdote) craved the ingestion of salt is due to his

A) lack of aldosterone, leading to loss of sodium into the urine.
B) hypothalamic damage.
C) excessive secretion of aldosterone.
D) impaired secretion of angiotensin II.
E) lack of renin, leading to loss of sodium into the urine.

Question 30

Activation of the anterior cingulate cortex would be expected to

A) blunt fluid intake in response to a hypotonic fluid challenge.
B) lower blood pressure.
C) produce overeating to obesity.
D) reflect the thirst state of the subject.
E) result in a hypotonic blood volume.

Question 31

During the fasting phase of metabolism,

A) blood glucose levels are increased.
B) body cells are able to use glucose.
C) the pancreas secretes ghrelin rather than insulin.
D) the liver converts glucose to glycogen.
E) the pancreas secretes glucagon rather than insulin.

Question 32

Imaging studies in humans given a hypertonic thirst suggest that the ________ is involved in the unpleasantness of osmometric thirst, while the ________ detects the tonicity of the blood plasma.

A) anterior cingulate cortex; lamina terminalis
B) insular cortex; medial amygdala
C) lamina terminalis; anterior cingulate cortex
D) subfornical fornical organ; area postrema
E) medial amygdala; insular cortex

Question 33

Which of the following would activate the volumetric thirst system without an action on osmometric thirst?

A) evaporation of water from the lungs.
B) severe constipation.
C) loss of blood after an automobile trauma.
D) ingestion of a bag of salted potato chips.
E) evaporation of water from the skin.

Question 34

Angiotensin II within the blood stimulates drinking by acting on cells within the

A) subfornical organ.
B) nucleus of the solitary tract.
C) lateral hypothalamus.
D) kidney.
E) atria of the heart.

Question 35

Our long-term fuel reservoir contains ________ and is located in ________.

A) glycogen; the liver
B) glycogen; the brain
C) triglycerides; fat cells
D) insulin; the pancreas
E) triglycerides; the liver

Question 36

The carbohydrate reservoir in the liver is primarily reserved for use

A) by the central nervous system.
B) by the liver.
C) by the muscles.
D) in the support of nonshivering thermogenesis.
E) in general metabolism.

Question 37

During the absorptive phase of metabolism,

A) blood glucose levels are lowered.
B) it has been some time since the person last ate food.
C) the pancreas secretes glucagon rather than insulin.
D) the liver converts glycogen to glucose.
E) blood glucose levels rise, which triggers the release of insulin by the pancreas.

Question 38

Our short-term fuel reservoir is located in ________ cells.

A) duodenal
B) stomach
C) liver and muscle
D) adipose tissue
E) pancreatic

Question 39

The ________ regions of the lamina terminalis contain osmoreceptors.

A) medial and dorsal
B) OVLT and subfornical organ
C) area postrema and OVLT
D) commissural
E) posterior

Question 40

An important physiological effect of angiotensin II is to

A) end the consumption of water after a thirst episode.
B) release hormones that cause the kidneys to excrete water and sodium.
C) decrease blood pressure.
D) promote the consumption of salt.
E) suppress food intake.

Question 41

Hypoglycemia induced by an injection of ________ results in ????_______.

A) ghrelin; satiety
B) 2-DG ; drinking
C) fenfluramine; conditioned satiety
D) insulin; eating
E) CCK; eating

Question 42

One explanation for why it is hard to maintain a low-calorie diet is that

A) food restriction elevates insulin release, which triggers feeding.
B) we are fundamentally too lazy to exercise.
C) starvation releases dopamine, which makes us happy.
D) food restriction elevates ghrelin release, which triggers hunger.
E) low calorie foods suppress ghrelin secretion.

Question 43

Mice that lack ________ insulin receptors show ________.

A) gut; obesity
B) brain; altered metabolism
C) brain; obesity
D) brain; rejection of a high-fat diet
E) gut; enhanced thermogenesis

Question 44

Plasma levels of ghrelin are highest _______ and lead to ________.

A) at the start of the morning; a craving for caffeine
B) after a meal; a craving for a cigarette
C) at the end of the evening; sleepiness
D) before a meal; eating
E) after a meal; consumption of a snack

Question 45

Which of the following is true of meal-related signals?

A) There are two sources of satiety signals that act to stop a meal.
B) There is only one satiety signal.
C) Ghrelin represents a short-term satiety signal.
D) Long-term satiety signals are generated by secretion of insulin and ghrelin.
E) Short-term satiety signals are secreted into the blood from adipose tissue.

Question 46

Studies of feeding using decerebrate rats indicate that

A) the feeding circuits for chewing are contained within the forebrain.
B) CCK acts on frontal cortex to stimulate eating.
C) the brainstem contains circuits that allow a rat to chew and to swallow.
D) decerebrate rats are unable to chew, swallow, or distinguish tastes.
E) the circuits controlling ingestion lie forward to the brainstem.

Question 47

"Head factors" in satiety

A) are restricted to the taste of food being eaten.
B) permit an animal to learn to adjust the amount consumed of food containing different amounts of calories.
C) produce long-lasting suppression of eating.
D) include activation of stretch receptors within the stomach.
E) are limited to a single class of nutrients.

Question 48

The primary hormone associated with the absorptive phase of metabolism is

A) glucagon.
B) CCK.
C) ghrelin.
D) insulin.
E) cortisol.

Question 49

Cholecystokinin

A) inhibits gastric contractions.
B) acts to stimulate eating via the ventromedial hypothalamus.
C) stimulates contraction of the gallbladder and pylorus.
D) inhibits eating.
E) blood levels are related to the sugar content of a meal.

Question 50

The ob mouse is obese because it lacks the gene that normally produces

A) CCK.
B) leptin.
C) insulin.
D) peptide YY.
E) glucagon.

Question 51

Match the correct behavior with the condition that precedes it:

A) meracaptoacetate; drinking
B) insulin; drinking
C) insulin; sexual behavior
D) ghrelin; eating
E) 2-DG; drinking

Question 52

Match up the correct behavior with the condition that precedes it:

A) mercaptoacetate; drinking
B) insulin; drinking
C) insulin; sexual behavior
D) mercaptoacetate; eating
E) 2-DG; drinking

Question 53

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.

Question 54

Which of the following is correct regarding the role of the liver in the regulation of eating?

A) Lipoprivation within the kidney after 2-DG infusion leads to eating.
B) Cutting the inputs of the liver abolished the effects of 2-DG on eating.
C) Deprivation of lipid metabolism within the liver after mercaptoacetate treatment leads to eating.
D) Infusion of sodium chloride into the hepatic portal vein increases the activity of the afferent fibers arising from the liver.
E) The liver senses the level of ghrelin in the blood and acts to reduce eating.

Question 55

We know that nutrient receptors are located within the intestines because

A) injection of nutrients into the duodenum will induce eating.
B) infusion of fatty acids into the duodenum increases the firing rate of afferent axons from the gut.
C) infusion of amino acids into the stomach increases the firing rate of afferent axons from the gut.
D) infusion of glucose into the duodenum increases the firing rate of afferent axons from the gut.
E) eating is not altered by surgery that cuts the gut afferents.

Question 56

The overeating noted in Prader-Willi syndrome is most likely to reflect

A) the inhibition of growth hormone.
B) chronically elevated levels of plasma ghrelin.
C) release of glucagon and insulin from the pancreas.
D) inhibition of gastric emptying.
E) chronically elevated levels of plasma cholecystokinin.

Question 57

Detectors for glucose are located within the

A) liver.
B) duodenum.
C) gut.
D) forebrain.
E) kidney.

Question 58

Ghrelin is a neuropeptide secreted from the ________ which functions to ________.

A) stomach; initiate eating
B) pancreas; inhibit eating
C) liver; alter insulin secretion
D) duodenum; control CCK levels in the plasma
E) PVN; inhibit eating

Question 59

The end of a meal may be signaled by a(n)

A) decrease in plasma leptin.
B) increase in plasma leptin.
C) decrease in plasma CCK
D) decrease in plasma ghrelin levels.
E) decrease in plasma peptide YY levels.

Question 60

The greatest degree of satiety would be expected for the situation involving

A) placing an amount 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.

Question 61

Which behavioral capacity below is retained in the decerebrate rat?

A) The capacity to approach food
B) The capacity to seek out and eat solid food.
C) The capacity to respond to hunger and satiety signals
D) The capacity to swallow large bits of solid food.
E) The ability to reject sweet tasting foods.

Question 62

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

Question 63

Administration of endocannabinoids, substances related to THC, stimulates eating by

A) inactivating ghrelin receptors.
B) blocking cholinergic receptors in the brain stem.
C) increasing the release of MCH and orexin.
D) activating MC4-receptors.
E) decreasing the release of MCH and orexin.

Question 64

Which of the following is true of MC4 receptors?

A) MC4-receptor activation stimulates eating.
B) A targeted mutation against the MC4-receptor leads to aphagia and death.
C) MC4-receptors are highly concentrated in the stomach and duodenum.
D) AGRP stimulates eating by blocking MC4-receptors.
E) NPY stimulates eating by stimulating MC4-receptors.

Question 65

Which terms below are synonymous?

A) orexins; hypocretins
B) insulin; glucagon
C) adrenaline; noradrenaline
D) NPY; CCK
E) satiety; hunger

Question 66

The peptides ________ and ________ act in the hypothalamus to increase eating in the rat.

A) insulin; CCK
B) serotonin; CCK
C) NPY; leptin
D) orexin; melanin-concentrating hormone
E) CCK; ghrelin

Question 67

Leptin inhibits eating via

A) blockade of the entry of insulin into brain.
B) activation of CCK receptors in brain.
C) inhibition of NPY, AGRP, and orexin neurons within the hypothalamus.
D) increasing the release of NPY in the hypothalamus.
E) inducing the stomach to release more ghrelin.

Question 68

A key pathway through which glucoprivic stimuli such as 2-DG act to stimulate feeding is

A) rostral pons -> reticular formation -> thalamus
B) subfornical organ -> median preoptic nucleus -> zona incerta
C) reticular formation -> lateral hypothalamus -> AGRP neurons in the PVN
D) ventrolateral medulla -> NPY neurons in the arcuate
E) ventrolateral medulla -> ghrelin receptors on hypothalamic neurons

Question 69

The notion that normal food intake is controlled by NPY is supported by the observation that

A) NPY strongly inhibits drinking.
B) NPY antagonists block the capacity of lithium chloride to induce taste aversion.
C) NPY levels are constant across the day-night cycle.
D) intra-hypothalamic injection of an NPY antagonist blocks the capacity of food deprivation to induce eating.
E) food deprivation does not alter the levels of NPY in the brain.

Question 70

The observation that the incidence of obesity has greatly increased over a few decades is unlikely to be due to

A) some innate aberration of metabolism.
B) increased exercise awareness of our citizens.
C) rapid changes in the gene pool.
D) smaller portions provided by fast-food restaurants.
E) the fact that we require fewer calories as we get older.

Question 71

Which pair of peptides below act as anorexigens?

A) CCK; ghrelin
B) ghrelin; CART
C) NPY; insulin
D) CART; alpha-MSH
E) NPY; AGRP

Question 72

Which pair below act as orexigens?

A) NPY; insulin
B) ghrelin; CART
C) CCK; ghrelin
D) CART; alpha-MSH
E) NPY; AGRP

Question 73

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/alpha-MSH neurons; NPY/AGRP neurons
B) insulin receptors; CCK receptors
C) ghrelin cells in the stomach; CART/alpha-MSH neurons
D) CCK-A receptors; serotonin neurons
E) PYY cells; MCH/orexin neurons

Question 74

A serious health hazard that accompanies obesity is

A) reduced cardiovascular disease.
B) diabetes.
C) heartburn.
D) stomach ulcers.
E) carpal tunnel syndrome.

Question 75

Ghrelin acts on ________ neurons to stimulate feeding.

A) NPY
B) angiotensin
C) MC4 receptors
D) leptin
E) agouti-related peptide

Question 76

The MC4 receptor is activated by and inhibited by ________.

A) nicotine; amphetamine
B) agouti-related protein; NPY
C) alpha-MSH; agouti-related protein
D) insulin; glucagon
E) alpha-MSH; CCK

Question 77

The effects of neuropeptide Y on ________ are localized within the ________.

A) eating; lateral hypothalamus
B) metabolism; lateral hypothalamus
C) eating; amygdala
D) eating; paraventricular hypothalamus
E) metabolism; arcuate hypothalamus

Question 78

Electrical stimulation of the lateral hypothalamus

A) elicits eating and drinking.
B) inhibits food intake.
C) produces sham feeding.
D) elicits repetitive chewing movements.
E) is an intensely aversive stimulus.

Question 79

Which of the following is considered to be an important factor that contributes to obesity?

A) overexertion in our jobs and spare time
B) learning to slowly eat your food
C) the fact that some persons are efficient at storing ingested calories as fat
D) the generous portions of low-calorie foods provided by fast-food restaurants
E) oversecretion of leptin

Question 80

Which of the following is true regarding the peptide cocaine- and amphetamine-regulated transcript (CART)?

A) CART activates eating of palatable foods.
B) CART is a peptide localized within the area posterma.
C) Infusion of an antibody to CART increases feeding.
D) CART activates MCH/orexin neurons.
E) Ghrelin stimulates CART neurons.