Deck 13: Homeostasis: Active Regulation of the Internal Environment

Question 1

The range of set points for body temperature for most mammals is

A) 20°‒30°C.
B) 35°‒50°C.
C) 36°‒38°C.
D) 25°‒30°C.

Answer 1

C

Question 2

Which of the following does not represent an obligatory loss for a female endotherm?

A) Breathing
B) Urinating
C) Copulating
D) Maintaining temperature

Answer 2

C

Question 3

Some animals such as certain beetles and fish can withstand body temperatures below 0°C because of

A) an "antifreeze" in their body fluids.
B) increased activity.
C) chemical reactions within cells.
D) super-strong cell walls that resist ice crystals.

Answer 3

A

Question 4

Specialized temperature receptors are found in the

A) hypothalamus.
B) body core.
C) skin.
D) All of the above

Question 5

The lowest level of the nervous system that is capable of producing thermoregulatory responses is the

A) spinal cord.
B) brainstem.
C) midbrain.
D) hypothalamus.

Question 6

The allostatic load is

A) the ability to predict the necessity of physiological changes.
B) a coordinated set of behavioral changes.
C) the cost of responses to avoid homeostatic deviation.
D) the energy used by an animal during 24-hour period.

Question 7

The difference between endotherms and ectotherms is that

A) ectotherms do not have set zones.
B) endotherms do not use negative feedback systems.
C) endotherms do not use behavioral mechanisms to regulate temperature.
D) ectotherms do not rely on metabolism or muscular activity to generate heat.

Question 8

The main selective advantage of endothermy appears to be the

A) relative instability of body temperature in endothermic species.
B) ability to sustain high levels of muscular activity.
C) lower energy requirements.
D) greater differential between metabolism during rest and during activity.

Question 9

Animals whose body temperature is regulated mainly by internal bodily processes are called

A) homeotherms.
B) poikilotherms.
C) endotherms.
D) ectotherms.

Question 10

The main weakness of the previously accepted distinction between "warm-blooded" and "cold-blooded" is that even cold-blooded animals

A) feel warm.
B) maintain body temperature.
C) eat.
D) detect temperature.

Question 11

A general feature of homeostatic mechanisms is

A) simplicity.
B) redundancy.
C) invariability.
D) All of the above

Question 12

Behavioral regulation of temperature, such as moving from a cool to a warm spot, is mediated by the

A) lateral hypothalamus.
B) preoptic area.
C) ventromedial hypothalamus.
D) amygdala.

Question 13

Behavioral regulation of body temperature, such as pressing a lever to turn on a heater, is

A) mediated by multiple brain regions.
B) eliminated by lesions of the preoptic area.
C) triggered by stimulation of the ventromedial hypothalamus.
D) eliminated by lesions of the lateral hypothalamus.

Question 14

Which of the following does not belong with the others?

A) Increased thyroid activity
B) Perspiration
C) Shivering
D) Constriction of cutaneous blood vessels

Question 15

Which behavior has not been identified as one of the general categories of behavior employed by animals for regulating body temperature?

A) Moving to a different location
B) Fanning themselves
C) Sticking out or retracting appendages
D) Altering insulation around the body

Question 16

Which statement regarding fluid in the body is true?

A) Most of the water in our body is in the extracellular compartment.
B) The interstitial fluid is classified as extracellular fluid.
C) Aquaporins continually move proteins in and out of cells.
D) The intracellular fluid of most animals is saltier than sea water.

Question 17

Which of the following species has the highest salt concentration in its extracellular fluid?

A) Clam
B) Whale
C) Lizard
D) Desert frog

Question 18

When water is lost by the body during perspiration or respiration, the intracellular fluid changes

A) with increased osmotic pressure and increased plasma volume.
B) with decreased osmotic pressure and no change in plasma volume.
C) with increased osmotic pressure and decreased plasma volume.
D) very little.

Question 19

Physiological saline is described as

A) hypotonic.
B) hypertonic.
C) isotonic.
D) infratonic.

Question 20

Refer to the figure.
The two chambers in the figure are separated by a semipermeable membrane. What will happen to the fluid levels if salt is added to the left chamber?

A) The solute concentration of the left chamber will increase, but the liquid levels will not change.
B) The difference in solute concentration will push salt and water molecules through the membrane until the concentrations are equivalent, which will overcome gravity and result in a higher level of fluid in the right chamber.
C) If enough salt is added, the difference in solute concentration will push salt molecules through the membrane until the osmotic pressure is less extreme, but the liquid levels will not change.
D) Water molecules from the right chamber will pass through the membrane until the ratio of water to salt is the same in both chambers, resulting in a higher level of fluid in the left chamber, despite gravity.

Question 21

When a cell comes into contact with hypotonic saline, it

A) immediately dies.
B) shrinks.
C) does not change.
D) swells.

Question 22

The response to an increase in cellular solute concentration is called _______ thirst.

A) hypovolemic
B) hypotonic
C) osmotic
D) osmoreceptive

Question 23

Which condition will trigger osmotic thirst?

A) Blood loss
B) Diarrhea
C) A salty meal
D) Drinking distilled water

Question 24

Hypovolemia is detected by specialized

A) osmoreceptors.
B) baroreceptors.
C) voleceptors.
D) hydroceptors.

Question 25

The receptors that detect hypovolemia are located in the

A) hypothalamus.
B) kidneys.
C) ventricular system.
D) vascular system.

Question 26

Osmotic thirst is triggered when

A) ion channels in stretchy neurons in the preoptic area, anterior hypothalamus, and supraoptic nucleus open.
B) baroreceptors in the hypothalamus sense increased concentrations in the extracellular fluid.
C) the organum vasculosum of the lamina terminalis and the subfornical organ sense a change in the volume of the extracellular fluid.
D) hypovolemia triggers the circumventricular organs via the fenestrated capillaries.

Question 27

Some seabirds, including gulls and petrels, can drink seawater because they get rid of excess salt by

A) producing concentrated urine.
B) producing concentrated feces.
C) excreting salt from salt glands.
D) laying eggs.

Question 28

Angiotensinogen in the blood is converted to angiotensin I by

A) the lungs.
B) renin.
C) aminopeptidase.
D) the circumventricular organs.

Question 29

The hormone _______, which induces drinking, is vital to the homeostasis of water balance due to hypovolemia.

A) corticosterone
B) vasopressin
C) angiotensin II
D) renin

Question 30

Which hormone causes blood vessels to constrict?

A) Neuropeptide Y
B) CCK
C) Oxytocin
D) Angiotensin II

Question 31

Which change is related to hypovolemia?

A) Decrease in vasopressin secretion
B) Decrease in atrial natriuretic peptide secretion
C) Stimulation of osmosensory neurons
D) Increased saltiness of the extracellular fluid

Question 32

Angiotensin II is produced in a reaction involving renin, which is secreted by the

A) adrenal glands.
B) kidneys.
C) pituitary gland.
D) subfornical organs.

Question 33

Angiotensin II acts on the _______ to provoke the release of _______.

A) hypothalamus; aldosterone
B) kidney; renin
C) adrenals; aldosterone
D) adrenals; vasopressin

Question 34

Which pancreatic hormone promotes the conversion of glycogen to glucose?

A) Glycogenolysis
B) Insulin
C) Glucagon
D) CCK

Question 35

Which form of diabetes results from the cessation of insulin production?

A) Diabetes insipidus
B) Type I diabetes
C) Type II diabetes
D) Congenital diabetes

Question 36

One of the reasons we know that insulin is not the only cue for satiety is that

A) insulin does not rise after a meal.
B) low doses of insulin do not stop eating.
C) high doses of insulin initiate eating.
D) untreated diabetic patients are not hungry.

Question 37

Refer to the figure.
Which choice correctly labels the figure?

A) I: Insulin required; II: No insulin required; III: Insulin; IV: Glucagon
B) I: Insulin required; II: No insulin required; III: Glucagon; IV: Insulin
C) I: No insulin required; II: Insulin required; III: Glucagon; IV: Insulin
D) I: No insulin required; II: Insulin required; III: Insulin; IV: Glucagon

Question 38

Comparing the basal metabolic rates of two animals, each with a body weight of 100 grams, you discover that species A has a higher metabolic rate than species

A) Species A
B) Species B
C) Neither, nonmammals do not weigh that much.
D) Neither, mammals do not weigh that little.

Question 39

The relationship of basal metabolism to body mass across species is described by _______ equation.

A) Garcia's
B) the dissipation
C) Kelvin's
D) Kleiber's

Question 40

The body tissues of animals generate heat from food as a consequence of

A) fat conversion.
B) intracellular combustion.
C) respiration.
D) the breakdown of chemical bonds.

Question 41

Studies with laboratory rats have shown that most of the energy available from a meal is consumed by

A) processing food.
B) basal metabolism.
C) muscular activity in behavioral processes.
D) brain activity.

Question 42

The relationship of basal metabolism to body mass across species does not hold for

A) very large mammals.
B) microorganisms.
C) an animal that is food-deprived or not at its target weight.
D) None of the above; the relationship holds for all of these groups.

Question 43

A treatment that increases the life span of lab animals is _______, which causes a(n) _______ in basal metabolism.

A) food deprivation; decrease
B) food deprivation; increase
C) ad lib feeding; decrease
D) ad lib feeding; increase

Question 44

Refer to the figure.
A herpetologist discovers a new species of gecko. If this new species' metabolism was evaluated, where would you expect it to appear on the graph?

A) I
B) II
C) III
D) IV

Question 45

One of the reasons we know that glucose is not the only cue for satiety is that

A) some meals have no glucose.
B) glucose is used only by the brain.
C) drinking glucose does not affect hunger.
D) untreated diabetics are hungry.

Question 46

Which pancreatic hormone promotes the conversion of glucose to glycogen?

A) Glycogenolysis
B) Insulin
C) Glucagon
D) CCK

Question 47

Research using fMRI shows that drinking glucose after fasting induces activity in the

A) basal forebrain.
B) medial hypothalamus.
C) medial amygdala.
D) brainstem.

Question 48

VMH-lesioned rats show

A) aphagia.
B) hyperphagia.
C) no change in food intake.
D) a loss of weight.

Question 49

Which animal does not regulate its body weight?

A) A rat with a recent LH lesion
B) A rat recovering from an LH lesion
C) A rat provided with a high-fat diet
D) A rat provided with a low-fat diet

Question 50

Refer to the figure, which shows changes in body weight in rats following hypothalamic lesioning.
Which answer accurately labels the data represented in the figure?

A) I: Recovered VMH-lesion; II: Normal, untreated; III: Recovered lateral hypothalamus-lesion
B) I: Normal, untreated; II: Recovered VMH-lesion; III: Recovered lateral hypothalamus-lesion
C) I: Recovered lateral hypothalamus-lesion; II: Normal, untreated; III: Recovered VMH-lesion
D) I: Recovered VMH-lesion; II: Normal, untreated; III: Normal, untreated

Question 51

Which of the following does not result from lesions of the VMH in rats?

A) An initial increase in weight if the animals are given high caloric, palatable food
B) Hyperphagia
C) Maintenance of high weight even with food deprivation
D) Defense of a new, higher target weight

Question 52

Which of the following is characteristic of rats recovering from large LH lesions?

A) Hyperphagia
B) Weight gain
C) Recovery of spontaneous eating when force-fed
D) Loss of weight with rich diet

Question 53

Which of the following would be a likely result of orexin injections into the lateral hypothalamus of rats?

A) Hyperphagia
B) Inhibition of the nucleus of the solitary tract
C) Stimulation of anorexigenic neurons
D) All of the above

Question 54

Leptin inhibits the secretion of _______, which is an endogenous antagonist of melanocortin receptors.

A) orexin
B) neuropeptide Y
C) -melanocyte stimulating hormone (-MSH)
D) agouti-related peptide (AgRP)

Question 55

Research on the effects of -MSH indicates that activation of melanocortin receptors in the hypothalamus

A) suppresses hunger.
B) induces hunger.
C) promotes leptin biosynthesis.
D) promotes orexin release.

Question 56

Injecting PYY_3-36 into rats causes them to

A) eat more.
B) eat less.
C) maintain their weight.
D) become thirsty.

Question 57

An injection of leptin into the brain would be most effective in altering feeding behavior and body weight if made directly to the

A) pituitary.
B) cortex.
C) choroid plexus.
D) hypothalamus.

Question 58

Which of the following is not an action of endocannabinoids on feeding control?

A) Stimulation of neurons in the PVN
B) Stimulation of POMC neurons
C) Stimulating the mesolimbic dopamine reward system
D) Inhibiting satiety signals from the gut

Question 59

Which of the following is a possible consequence of antibiotic treatments?

A) Obesity
B) Development of an ulcer
C) Weight loss, due to shedding 7-10 pounds of gut microbes
D) Both a and b

Question 60

Which treatment is a promising new approach for restoring a healthy enterotype?

A) Supervised weight gain
B) A high carbohydrate diet
C) Fecal transplantation
D) Antibiotic treatment

Question 61

Appetite control can be achieved via which of the following pharmacological means?

A) Rimonabant, which is a cannabinoid antagonist in widespread use
B) Lorcarserin, a drug that activates the MC4R melanocortin receptor and that produces significant results
C) Drugs that activate serotonin 5-HT2C receptors on POMC neurons and also cause mood problems
D) PYY_?3-36 receptor antagonists via nasal spray

Question 62

When fat deposits were removed from ground squirrels during their annual phase of weight loss, the animals

A) passively accepted the weight loss.
B) regained weight before starting to lose again.
C) continued to lose weight, going to a lower trough than they would have normally.
D) no longer showed their usual circannual cycle.

Question 63

Refer to the figure.
A patient elected to have the surgery illustrated in the figure to treat their type II diabetes. What kind of surgery did the patient choose?

A) Roux-en-Y gastric bypass surgery to reduce nutrient absorption and ghrelin secretion
B) Sleeve gastrectomy to reduce nutrient absorption and ghrelin secretion
C) Colectomy to reduce nutrient absorption.
D) Gastrectomy to improve the gut microbiota

Question 64

People suffering from anorexia nervosa

A) have no appetite.
B) think about food a great deal.
C) have an autoimmune disease.
D) gain weight.

Question 65

_______ is the term referring to the maintenance of consistent states of the body.

Question 66

_______ is the term referring to the maintenance of consistent states of the body.

Question 67

Endotherms may show a significant, endogenously induced departure from their average body temperatures known as _______.

Question 68

Although rat pups regulate body temperature poorly, they do produce some heat from _______ located between the shoulder blades.

Question 69

A(n) _______ solution is a solution with the same concentration as physiological saline.

Question 70

The brain responds to hypovolemia by triggering both thirst and hunger for _______.

Question 71

Two physiological responses to hypovolemia are constriction of blood vessels and the secretion of _______.

Question 72

Another name for vasopressin, which relates to its physiological effects, is _______ hormone.

Question 73

The hormone _______ is generated via a cascade of enzymatic action in response to hypovolemia.

Question 74

The hormone _______ acts to conserve sodium by acting on the kidney.

Question 75

Long-term energy storage is accomplished by storage of fat in _______ tissue.

Question 76

The body stores glucose for later use after first converting it to a more complex form called _______.

Question 77

About 55% of the energy we ingest is used for _______.

Question 78

About 12% of the energy we ingest is used for _______ processes.

Question 79

The stimuli associated with food, such as its smell, provoke the release of insulin during the _______ phase of insulin release.

Question 80

Leptin modulates the release of a variety of peptides after it has reached the _______ nucleus of the hypothalamus.