Thermoregulation in Animals
19 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary source of heat energy for ectotherms?

  • Muscular activity
  • External environment (correct)
  • Internal reactions
  • Metabolic processes

    • What is the definition of thermal acclimatization?

  • A structural or metabolic change in the limits of tolerable temperatures as the environment alternates between warm and cool seasons (correct)
  • A change in body size to adapt to different environmental temperatures
  • The process of generating heat through shivering
  • The ability to maintain a constant body temperature regardless of external conditions

    • Which of the following is a common adaptation used by some organisms to survive freezing temperatures?

  • Production of antifreeze proteins (correct)
  • Migration to warmer climates
  • Increased metabolic rate
  • Hibernation

    • What is the role of the hypothalamus in thermoregulation?

    <p>Acting as the body's thermostat (C)</p> Signup and view all the answers

    How does the hypothalamus respond to a decrease in core body temperature?

    <p>Triggering shivering (C)</p> Signup and view all the answers

    What happens when there is a disruption of the normal negative feedback loop in the hypothalamus?

    <p>A disease like goiter can develop (D)</p> Signup and view all the answers

    Which of the following is NOT a function of the hypothalamus?

    <p>Producing digestive enzymes (A)</p> Signup and view all the answers

    What physiological response occurs when the signals cause vasodilation of arterioles in the skin?

    <p>Increased blood flow and heat loss from the body surface (A)</p> Signup and view all the answers

    Which of the following animals is known for dissipating heat through their large ears?

    <p>Elephant (C)</p> Signup and view all the answers

    During what conditions is the temperature set point typically lowered in many birds and mammals?

    <p>During cooler conditions accompanied by torpor (D)</p> Signup and view all the answers

    What is the primary role of a fever in the body?

    <p>To raise the internal temperature set point for immune response (A)</p> Signup and view all the answers

    Which of the following best describes torpor?

    <p>A state of physical or mental inactivity and lethargy (A)</p> Signup and view all the answers

    What is the main function of the thyroid gland?

    <p>To produce hormones that regulate metabolism (B)</p> Signup and view all the answers

    What is the effect of iodine deficiency on the thyroid gland?

    <p>The thyroid gland enlarges in an attempt to produce more thyroid hormone. (A)</p> Signup and view all the answers

    What is the role of TSH (Thyroid Stimulating Hormone) in thyroid function?

    <p>TSH is produced by the pituitary gland and stimulates the release of T3 and T4. (B)</p> Signup and view all the answers

    Which of the following is a mechanism the body uses to regulate heat loss?

    <p>Dilating or constricting blood vessels in the skin (D)</p> Signup and view all the answers

    Which of the following is an example of a countercurrent heat exchange system?

    <p>The circulatory system of a whale (C)</p> Signup and view all the answers

    How does vasoconstriction help the body maintain a stable core temperature?

    <p>It decreases blood flow to the surface of the skin, reducing heat loss. (A)</p> Signup and view all the answers

    How does an insulating layer of fat beneath the skin help to regulate body temperature?

    <p>It helps to reduce heat loss by trapping heat near the body. (B)</p> Signup and view all the answers

    Flashcards

    Thermoregulation

    The process of maintaining optimal body temperature for physiological performance.

    Ectotherms

    Animals that obtain heat energy from the external environment, like most fish, amphibians, and reptiles.

    Endotherms

    Animals that produce heat internally to maintain body temperature, such as birds and mammals.

    Thermal Acclimatization

    Adaptive changes in an organism to survive varying temperature conditions over seasons.

    Signup and view all the flashcards

    Hypothalamus

    Brain region acting as the body's thermostat, regulating temperature and other homeostatic functions.

    Signup and view all the flashcards

    Negative Feedback

    Mechanism where a change triggers a response that counteracts that change, maintaining stability.

    Signup and view all the flashcards

    Torpor

    A state of decreased physiological activity to conserve energy, often related to thermoregulation.

    Signup and view all the flashcards

    Antifreeze proteins

    Proteins that help some animals survive freezing temperatures by preventing ice formation in their bodies.

    Signup and view all the flashcards

    Vasodilation

    Relaxation of smooth muscles in arterioles, increasing blood flow to the skin.

    Signup and view all the flashcards

    Hibernation

    Extended torpor during winter months in small mammals to conserve energy.

    Signup and view all the flashcards

    Fever

    Temporary increase in body temperature, typically due to infection, signaling the immune response.

    Signup and view all the flashcards

    Adaptations for cooling

    Structural or behavioral traits to dissipate heat, like elefants' large ears or penguins' exposed skin.

    Signup and view all the flashcards

    Thyroid Function

    The thyroid produces hormones affecting metabolism and growth.

    Signup and view all the flashcards

    Thyroid Hormones

    Includes T3 (triiodothyronine) and T4 (thyroxine) produced by the thyroid.

    Signup and view all the flashcards

    Iodine's Role

    Iodine is essential for the thyroid to produce T3 and T4.

    Signup and view all the flashcards

    Hypothyroidism

    Condition due to low levels of T3 and T4, often from iodine deficiency.

    Signup and view all the flashcards

    Negative Feedback in Endocrine System

    Regulatory mechanism that maintains hormone levels within a range.

    Signup and view all the flashcards

    Vasoconstriction

    Blood vessels tighten to reduce blood flow and heat loss.

    Signup and view all the flashcards

    Study Notes

    Thermoregulation in Animals

    • Animals maintain body temperature for optimal physiological performance.

    • Organismal performance depends on the rate and efficiency of biochemical, physiological, and whole-body processes.

    • Ectotherms obtain heat from the external environment (most fish, amphibians, and reptiles).

    • Endotherms generate heat internally (birds and mammals).

    Thermoregulation

    • Thermoregulation in Ectotherms

      • Thermal Acclimatization: Structural or metabolic changes to adjust to varying temperatures (warm/cool seasons). This helps animals perform well in different temperatures
      • Allows animals to perform well in winter and summer
      • May involve enzyme changes or phospholipid/cholesterol level adjustments

    • Thermoregulation in Endotherms

      • Maintaining a narrow body temperature range.
      • Balancing internal heat production and heat loss through the body surface

    Negative Feedback: Endocrine System

    • Hypothalamus: acts as a body's thermostat controlling homeostatic functions.

      • Thyroid regulates a wide variety of functions in the body.
      • Thyroid Releasing Hormone (TRH)
      • Thyroid Stimulating Hormone (TSH)
      • Triiodothyronine (T3)
      • Thyroxine (T4)
      • Iodine is crucial for thyroid hormone production.

    • Low iodine intake leads to hypothyroidism

      • Thyroid cannot make T3 and T4
      • Low T3 and T4 levels despite TSH stimulation.
      • The thyroid enlarges as a response, causing goiter.

    • Calcium regulation, Sodium regulation

    • Negative feedback control systems.

    • Examples are blood calcium level and sodium levels.

    The Skin and Endothermy

    • Skin is a vital organ of heat transfer.
    • Blood vessels regulate heat loss by constricting or dilating (vasoconstriction/vasodilation).
    • Impermeable to water, reducing heat loss from evaporation of body fluids.

    Keeping Warm

    • When core temperature falls below set point, hypothalamus triggers responses through the autonomic nervous system
    • Immediate responses: vasoconstriction (constriction of arterioles in the skin) to reduce blood flow to the skin's capillary networks.

    Examples of Keeping Warm

    • Many mammals: uneven distribution of fur.
    • Birds and mammals: veins and arteries positioned in legs.
    • Whales and seals: adjustments in blood flow for warmth.

    Keeping Cool

    • When core temperature rises above set point, hypothalamus signals the autonomic system to lower body temperature
    • Immediate response: vasodilation (relaxation of arterioles in skin) increases blood flow and heat loss from the body's surface.

    Examples of Keeping Cool

    • Birds: fly with extended legs.
    • Penguins: expose featherless patches of skin.
    • Elephants: dissipate heat from large ears

    Structural and Behavioral Adaptations

    • Adaptations for keeping warm and/or cool.
    • Examples include animals shown in images.

    Temperature Variations

    • Temperature set point varies daily and seasonally in many birds and mammals.
    • Torpor occurs during cooler conditions (lowered set point)
    • Daily torpor, Seasonal torpor, Hibernation

    What Happens if Core Temperature Gets Too High?

    • Temporary increase in body temperature (fever), usually due to infection.
    • Foreign bodies increase hypothalamus internal temperature set point
    • Immune system is activated.
    • Mild fever is manageable but high fever can be critical.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Lecture 5: Thermoregulation PDF

    Description

    Explore the fascinating principles of thermoregulation in animals, focusing on how ectotherms and endotherms maintain their body temperature. Learn about the physiological adaptations that enable these organisms to thrive in varying environmental conditions, including thermal acclimatization and the role of the hypothalamus as the body's thermostat.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser