9. Internal Regulation Flashcards
What does negative feedback do?
a. It establishes a set point.
b. It changes the set point.
c. It eliminates the set point.
d. It reduces discrepancies from a set point.
d. It reduces discrepancies from a set point.
How do poikilothermic (ectothermic) animals regulate their body temperature, if at all?
a. They move to a location with a more favorable temperature.
b. They use physiological mechanisms such as shivering and sweating.
c. They increase their metabolic rate.
d. They do not regulate their body temperature at all.
a. They move to a location with a more favorable temperature.
What is the primary advantage of maintaining a constant high body temperature?
a. It saves us the energy from having to look for a comfortable temperature.
b. It enables us to survive in warmer climates.
c. It keeps the muscles ready for rapid, prolonged activity even in cold weather.
d. Other things being equal, animals with a higher body temperature live longer than those with a lower temperature.
c. It keeps the muscles ready for rapid, prolonged activity even in cold weather.
If we inserted a probe into the POA/AH and directly heated that area, what if anything would happen?
a. The animal would shiver.
b. The animal would sweat or pant.
c. The animal would not react physiologically, but it would seek a cooler location.
d. The animal would not react in any way that affects body temperature.
b. The animal would sweat or pant.
When you have an infection, what causes the fever?
a. The infective agent directly stimulates the heart to beat faster.
b. The infective agent directly stimulates the muscles to shiver.
c. The immune system increases delivery of prostaglandins and histamine to the POA/AH.
d. The immune system decreases blood flow to the brain.
c. The immune system increases delivery of prostaglandins and histamine to the POA/AH.
Which of the following is the most correct description of a fever?
a. Fever is one way by which the body fights against bacteria.
b. Fever is one way in which bacteria cause damage to the body.
c. Fever is an indication that the POA/AH is not functioning properly.
d. Fever occurs only in homeothermic animals.
a. Fever is one way by which the body fights against bacteria.
If you lacked vasopressin, how would your drinking change, if at all?
a. Your drinking would not change.
b. You would drink less.
c. You would drink more.
c. You would drink more.
What would happen as a result of adding salt to the body’s extracellular fluids?
a. Increased osmotic thirst
b. Decreased osmotic thirst
c. Increased hypovolemic thirst
d. Decreased hypovolemic thirst
a. Increased osmotic thirst
How does hypovolemic thirst differ from osmotic thirst?
a. Hypovolemic thirst is stronger.
b. Osmotic thirst is stronger.
c. Someone with hypovolemic thirst prefers slightly salty water.
d. Someone with hypovolemic thirst prefers pure water.
c. Someone with hypovolemic thirst prefers slightly salty water.
People differ in their likelihood of consuming milk products in adulthood because of what type of genetic difference?
a. Genetic variants in taste buds
b. Genetic variants in neurotransmitters of the hypothalamus
c. Genetic variants in ability to metabolize lactose
d. Genetic variants in mechanisms of hypovolemic thirst
c. Genetic variants in ability to metabolize lactose
Which of the following describes the relationship between taste and eating?
a. Taste is sufficient to control eating.
b. Taste is necessary for eating.
c. Taste is both necessary and sufficient for eating.
d. Taste is neither necessary nor sufficient for eating, although it contributes
d. Taste is neither necessary nor sufficient for eating, although it contributes
After surgical removal of someone’s stomach, what mechanism if any can produce satiety?
a. Distension of the duodenum
b. Entry of nutrients into the muscles and organs
c. None. The person stops eating altogether.
d. None. The person starts eating constantly.
a. Distension of the duodenum
When food distends the duodenum, the duodenum releases the hormone CCK. By what peripheral (non-CNS) mechanism does it increase satiety?
a. CCK increases stomach contractions.
b. CCK tightens the sphincter muscle between the stomach and the duodenum.
c. CCK increases the ability of nutrients to enter cells.
d. Cells in the hypothalamus release CCK as a neurotransmitter.
b. CCK tightens the sphincter muscle between the stomach and the duodenum.
Increased blood glucose causes increased release of ___, which ___ the ability of glucose to enter the cells.
a. insulin . . . increases
b. insulin . . . decreases
c. glucagon . . . increases
d. glucagon . . . decreases
a. insulin . . . increases
People with untreated type 1 diabetes have ___ levels of insulin, ___ levels of blood glucose, and ___ levels of hunger.
a. high . . . high . . . high
b. low . . . high. . . . high
c. low . . . low . . . high
d. low . . . low . . . low
e. low . . . high . . . low
b. low . . . high. . . . high
Leptin is produced by the ___ cells. In most cases it tends to ___ appetite.
a. fat . . . decrease
b. hypothalamic . . . decrease
c. pancreas . . . increase
d. intestinal . . . increase
a. fat . . . decrease
Which is the only neuropeptide that increases hunger?
a. Ghrelin
b. Melanocortin
c. Leptin
d. Insulin
a. Ghrelin
How do taste and ghrelin promote eating and arousal?
a. They increase excitation from the paraventricular nucleus to the arcuate nucleus, an area that excites the lateral hypothalamus.
b. They increase inhibition from the paraventricular nucleus to the arcuate nucleus, an area that inhibits the lateral hypothalamus.
c. They increase excitation from the arcuate nucleus to the paraventricular nucleus, an area that excites the lateral hypothalamus.
d. They increase inhibition from the arcuate nucleus to the paraventricular nucleus, an area that inhibits the lateral hypothalamus.
d. They increase inhibition from the arcuate nucleus to the paraventricular nucleus, an area that inhibits the lateral hypothalamus.
.If researchers could find a safe drug that stimulates melanocortin receptors, what would be the probable benefit?
a. Improving memory
b. Helping people go to sleep
c. Combatting anorexia nervosa
d. Helping people lose weight
d. Helping people lose weight
The lateral hypothalamus facilitates feeding in several ways. Which of the following is not one of them?
a. It alters taste sensations.
b. It enhances responses to food in the cerebral cortex.
c. It increases insulin secretion.
d. It decreases digestive secretions.
d. It decreases digestive secretions.
Damage to the ventromedial hypothalamus produces a steady increase in the release of insulin. Which of the following is a consequence?
a. The animal decreases its appetite for carbohydrates.
b. More of each meal is stored as fat.
c. The animal eats fewer, but larger meals.
d. Body temperature increases.
b. More of each meal is stored as fat.
What evidence suggests that high ghrelin levels lead to weight gain in Prader-Willi syndrome?
a. People with this syndrome continue to have high ghrelin levels regardless of whether they gain or lose weight.
b. A mutated gene for melanocortin causes nearly 5 percent of cases of severe obesity.
c. Ghrelin stimulates hunger-related neurons in the arcuate nucleus.
d. People with Prader-Willi syndrome have other problems in addition to weight gain.
a. People with this syndrome continue to have high ghrelin levels regardless of whether they gain or lose weight.
How has the prevalence of obesity changed since the availability of high-fructose corn syrup and artificially sweetened diet beverages?
a. Each of them helped lower the prevalence of obesity.
b. High-fructose corn syrup helped lower obesity rates, but diet drinks did not.
c. Diet drinks helped lower obesity rates, but high-fructose corn syrup did not.
d. The prevalence of obesity has increased after the availability of both of these.
d.The prevalence of obesity has increased after the availability of both of these.
People with bulimia have elevated ghrelin levels. Is this abnormality a likely cause of bulimia? And what is the evidence?
a. No. It is probably not a cause. The abnormality is common in the ethnic groups who are most likely to develop bulimia.
b. No. It is probably not a cause. As people recover from bulimia, their ghrelin level returns toward normal.
c. Yes. It is probably a cause. People who show high ghrelin early in life are likely to develop bulimia later.
d. Yes. It is probably a cause. Inducing high ghrelin in rats causes the rats to develop bulimia.
b.No. It is probably not a cause. As people recover from bulimia, their ghrelin level returns toward normal.
How does the idea of allostasis differ from homeostasis?
Homeostasis is a set of processes that keep certain body variables within a fixed range. Allostasis is an adjustment of that range, increasing it or decreasing it as circumstances change.
What is the primary advantage of maintaining a constant high body temperature?
A constant high body temperature keeps an animal ready for rapid, prolonged muscle activity even in cold weather.
Why did mammals evolve a temperature of 37°C (98°F) instead of some other temperature?
Animals gain an advantage in being as warm as possible and therefore as fast as possible. However, proteins lose stability at temperatures much above 37°C (98°F).
What are the sources of input to the POA/AH?
The POA/AH receives input from temperatures in the skin, the organs, and the brain including cells in the POA/AH itself. It also receives prostaglandins and histamines when the immune system detects an infection.
How can an animal regulate body temperature after damage to the POA/AH?
It can regulate temperature through behavior, such as by finding a warmer or cooler place.
What evidence indicates that fever is an adaptation to fight illness?
The body will shiver or sweat to maintain its elevated temperature at a nearly constant level. Also, fish, reptiles, and immature mammals with infections use behavioral means to raise their temperature to a feverish level. Furthermore, a moderate fever inhibits bacterial growth and increases the probability of surviving a bacterial infection.
If you lacked vasopressin, would you drink like a beaver or like a gerbil? Why?
If you lacked vasopressin, you would have to drink more like a beaver. You would excrete much fluid, so you would need to drink an equal amount to replace it.
Would adding salt to the body’s extracellular fluids increase or decrease osmotic thirst?
Adding salt to the extracellular fluids would increase osmotic thirst because it would draw water from the cells into the extracellular spaces.
Who would drink more pure water—someone with osmotic thirst or someone with hypovolemic thirst?
Someone with osmotic thirst would drink more water. Someone with hypovolemic thirst would drink more of a solution containing salts.
What genetic difference is most important for variants in likelihood of drinking milk in adulthood?
Likelihood of drinking milk in adulthood depends largely on a gene that controls the ability to digest lactose, the main sugar in milk.
