Podcast
Questions and Answers
Which physiological changes are characteristic of animals undergoing hibernation?
Which physiological changes are characteristic of animals undergoing hibernation?
- Significant reduction in heart rate and slowed respiration. (correct)
- Increased blood flow to extremities to prevent freezing.
- Rapid shifts between periods of activity and rest.
- Increased metabolic rate and elevated body temperature.
How does winter dormancy in bears differ from true hibernation observed in smaller mammals?
How does winter dormancy in bears differ from true hibernation observed in smaller mammals?
- Bears enter a comatose state, while smaller mammals remain active.
- Bears maintain a significantly higher metabolic rate during dormancy compared to hibernating mammals.
- Bears lower their body temperature by approximately 5°C and reduce metabolism by about 50%, whereas true hibernators can experience more extreme changes. (correct)
- Bears experience a drastic drop in body temperature to below freezing, unlike smaller mammals.
What is the primary purpose of countercurrent exchange in the head for animals in hot environments?
What is the primary purpose of countercurrent exchange in the head for animals in hot environments?
- To increase the rate of blood flow to the brain, allowing for heightened cognitive function.
- To equalize the temperature between arterial and venous blood, which will help in thermoregulation.
- To cool the blood traveling to the brain by utilizing evaporative heat loss in the nasal passages. (correct)
- To increase blood temperature, which will help prevent heat stroke.
Which adaptation allows camels to conserve water in hot environments?
Which adaptation allows camels to conserve water in hot environments?
How do small and large mammals differ in their adaptations to heat regarding homeostasis?
How do small and large mammals differ in their adaptations to heat regarding homeostasis?
Which physiological process is NOT a primary mechanism by which endotherms maintain a stable body temperature?
Which physiological process is NOT a primary mechanism by which endotherms maintain a stable body temperature?
What is the key trade-off for endotherms in maintaining a high body temperature, compared to ectotherms?
What is the key trade-off for endotherms in maintaining a high body temperature, compared to ectotherms?
How does insulation primarily assist endotherms in cold environments?
How does insulation primarily assist endotherms in cold environments?
Why do smaller mammals and birds typically exhibit facultative hypothermia more often than larger animals?
Why do smaller mammals and birds typically exhibit facultative hypothermia more often than larger animals?
Which of the following is an example of seasonal hypothermia?
Which of the following is an example of seasonal hypothermia?
During migratory stopovers, some birds exhibit rest-phase hypothermia. What is the primary benefit of this behavior?
During migratory stopovers, some birds exhibit rest-phase hypothermia. What is the primary benefit of this behavior?
How does molting in birds and mammals relate to thermoregulation?
How does molting in birds and mammals relate to thermoregulation?
What is the lower critical temperature (LCT) in the context of endothermy?
What is the lower critical temperature (LCT) in the context of endothermy?
How does the thermoneutral zone relate to the metabolic rate of an endotherm?
How does the thermoneutral zone relate to the metabolic rate of an endotherm?
In the context of endothermy, what is the significance of the lower critical temperature (LCT)?
In the context of endothermy, what is the significance of the lower critical temperature (LCT)?
How does increased insulation affect the lower critical temperature (LCT) in endotherms?
How does increased insulation affect the lower critical temperature (LCT) in endotherms?
What physiological challenge do thermoregulation adaptations, such as sweating or panting, primarily address for endotherms?
What physiological challenge do thermoregulation adaptations, such as sweating or panting, primarily address for endotherms?
How does the shedding or molting of insulation in mammals and birds relate to thermoregulation?
How does the shedding or molting of insulation in mammals and birds relate to thermoregulation?
What is the key advantage of an endotherm's ability to maintain a high body temperature, particularly in the context of ecological niche?
What is the key advantage of an endotherm's ability to maintain a high body temperature, particularly in the context of ecological niche?
What physiological process underlies the ability of camels to conserve water using countercurrent exchange in the nasal passages?
What physiological process underlies the ability of camels to conserve water using countercurrent exchange in the nasal passages?
How do camels use thermal inertia to cope with desert environments?
How do camels use thermal inertia to cope with desert environments?
Why might some mammals and birds create nests and huddle together in cold environments?
Why might some mammals and birds create nests and huddle together in cold environments?
What is the primary reason that endotherms require a higher metabolic rate compared to ectotherms of similar size?
What is the primary reason that endotherms require a higher metabolic rate compared to ectotherms of similar size?
What is NOT a primary function of 'winter dormancy' in animals such as bears?
What is NOT a primary function of 'winter dormancy' in animals such as bears?
What is the relationship between surface area-to-volume ratio and heat loss in the endotherms?
What is the relationship between surface area-to-volume ratio and heat loss in the endotherms?
In relation to thermoregulation, what advantage do small mammals gain from limiting their exposure to the sun and cooling down quickly?
In relation to thermoregulation, what advantage do small mammals gain from limiting their exposure to the sun and cooling down quickly?
What is the primary physiological trade-off associated with endothermy?
What is the primary physiological trade-off associated with endothermy?
During winter dormancy, bears undergo a period of reduced metabolic activity. What is the key physiological adaptation that allows them to survive this period without significant muscle loss?
During winter dormancy, bears undergo a period of reduced metabolic activity. What is the key physiological adaptation that allows them to survive this period without significant muscle loss?
What is the benefit of rest-phase hypothermia for birds during migratory stopovers?
What is the benefit of rest-phase hypothermia for birds during migratory stopovers?
Why do flying animals, such as birds, face unique thermoregulatory challenges compared to terrestrial mammals?
Why do flying animals, such as birds, face unique thermoregulatory challenges compared to terrestrial mammals?
Certain mammals use communal hibernation. What impact does this adaptation have on energy expenditure and thermoregulation?
Certain mammals use communal hibernation. What impact does this adaptation have on energy expenditure and thermoregulation?
How does the regulation of blood flow contribute to thermoregulation in endotherms facing cold stress?
How does the regulation of blood flow contribute to thermoregulation in endotherms facing cold stress?
Flashcards
Hibernation
Hibernation
A state where small mammals become essentially comatose, with body temperature at or below freezing, slow respiration, reduced heart rate, and blood concentrated in the core.
Rest-phase hypothermia
Rest-phase hypothermia
Decreased body temperature and metabolic rate during rest.
Heat Avoidance
Heat Avoidance
Seeking shelter, climbing, or flying to avoid exposure to high temperatures.
Thermal Inertia
Thermal Inertia
Signup and view all the flashcards
Countercurrent Exchange in the Head
Countercurrent Exchange in the Head
Signup and view all the flashcards
Endothermy
Endothermy
Signup and view all the flashcards
Lower Critical Temperature (LCT)
Lower Critical Temperature (LCT)
Signup and view all the flashcards
Benefit of Endothermy
Benefit of Endothermy
Signup and view all the flashcards
Cost of Endothermy
Cost of Endothermy
Signup and view all the flashcards
Insulation and LCT
Insulation and LCT
Signup and view all the flashcards
Facultative Hypothermia
Facultative Hypothermia
Signup and view all the flashcards
Seasonal Hypothermia
Seasonal Hypothermia
Signup and view all the flashcards
Homeostasis Relaxation by Small Mammals
Homeostasis Relaxation by Small Mammals
Signup and view all the flashcards
Seasonal Insulation Change
Seasonal Insulation Change
Signup and view all the flashcards
Study Notes
- Endothermy is the production of heat to maintain a constant, normal body temperature.
- Air temperature is usually lower than body temperature.
- Body temperature can be increased by metabolism, thermogenesis, and insulation.
- Body temperature can be decreased by sweating or panting.
- The lower critical temperature (LCT) is the point where an animal must increase metabolic heat production to balance heat loss.
- Endotherms can maintain stable body temperatures over a range of environmental temperatures.
Benefits of Endothermy
- The ability to maintain a high body temperature when solar radiation is unavailable or insufficient, such as at night or in winter.
- Endothermy allows for living in cold-weather climates due to thermoregulatory capacity.
Costs of Endothermy
- Endothermy is energetically expensive.
- Endothermy requires a higher metabolic rate.
- Gram-for-gram endotherms need more food than ectotherms.
Adaptations to the Cold
- Insulation greatly decreases LCT.
- Most mammals and birds shed or molt their insulation in the autumn and spring because winter insulation is denser than summer coverings.
- Animals avoid going outside as often and create nests to share body heat.
Facultative Hypothermia
- Facultative hypothermia is the intentional lowering of body temperature.
- It is common in small mammals and birds.
- There is a large surface/volume ratio, meaning that heat loss is high.
- There are also large food requirements because the energy consumed per gram of body weight is higher than in larger species.
- Layers of insulation are thinner than those of larger animals.
Seasonal Hypothermia
- Seasonal hypothermia reduces body temperature up to 5°C in the winter, by up to 5 degrees
- Time outside of nests is limited.
Rest-Phase Hypothermia
- Rest-phase hypothermia decreases of body temperature from 5-10°C during normal times of inactivity.
- An example of this is migratory stopovers.
Hibernation
- Hibernation generally occurs only in small mammals where they essentially become comatose.
- Body temperature can be at or below freezing.
- Respiration is slow.
- Heart rate is reduced.
- Blood stays in the core.
- Some animals use communal hibernation.
- Bears do not hibernate, instead enter winter dormancy, which only decreases body temperature about 5°C and metabolism decreases by about 50%.
Adaptations for Heat
- Avoidance: Shelter during the heat of the day, climbing away from the ground, and flying above the heat.
- Relaxation of Homeostasis: Small mammals limit their exposure and can cool down quickly.
- Large mammals use more of their thermal inertia.
- Camels lay on the cool ground in the morning in groups and conserve water by not using evaporative heat loss.
Countercurrent Exchange in the Head
- The blood being carried to the brain passes by the blood coming back from the nasal passages.
- The blood coming back from the nasal passages is cooler because of evaporative heat loss in the nose.
- This cools the blood coming from the heart before it reaches the brain.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
