Biol 224.3 - Animal Body Systems - Lecture 4: Homeostasis
26 Questions
1 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 role of a negative feedback mechanism?

  • To maintain a steady state by counteracting changes in a variable (correct)
  • To amplify a change in a variable and move it further away from the set point
  • To predict future needs and adjust physiological responses accordingly
  • To initiate a change in a variable by adjusting the set point

    • What is a key difference between homeotherms and heterotherms?

  • Homeotherms are generally more active at night, while heterotherms are more active during the day
  • Homeotherms obtain heat primarily from external sources, while heterotherms rely on internal sources
  • Homeotherms are typically found in warmer climates, while heterotherms are adapted to colder environments
  • Homeotherms maintain a relatively constant internal temperature, while heterotherms have fluctuating body temperatures (correct)

    • What type of feedback mechanism is involved in the rising phase of a nerve action potential?

  • Negative feedback
  • Positive feedback (correct)
  • Feedforward
  • None of the above

    • Which of the following organisms would be classified as an ectotherm?

    <p>Lizard (A)</p> Signup and view all the answers

    Which of the following is NOT a characteristic of feedforward mechanisms?

    <p>They directly counteract deviations from a set point (D)</p> Signup and view all the answers

    What is the role of oxytocin in childbirth?

    <p>To initiate contractions of the uterus (A)</p> Signup and view all the answers

    Which of the following processes exemplifies positive feedback?

    <p>Blood clotting (D)</p> Signup and view all the answers

    What is the primary source of heat for endotherms?

    <p>Internal metabolic processes (C)</p> Signup and view all the answers

    What is the primary regulatory mechanism used by endotherms to maintain body temperature?

    <p>Negative feedback loops (A)</p> Signup and view all the answers

    Which physiological response is primarily involved when body temperature rises above the set point?

    <p>Increased blood flow to skin (C)</p> Signup and view all the answers

    How do terrestrial reptiles primarily regulate their temperature compared to endotherms?

    <p>By migrating to different environments (D)</p> Signup and view all the answers

    What role does the hypothalamus play in thermoregulation for endotherms?

    <p>It integrates responses to temperature changes. (B)</p> Signup and view all the answers

    What triggers the cooling physiology when body temperature exceeds the set point?

    <p>Activation of sweating and panting (B)</p> Signup and view all the answers

    What characterizes ectothermic animals in relation to their body temperature?

    <p>Their body temperature is influenced directly by the surrounding environmental temperature. (A)</p> Signup and view all the answers

    Which of the following is an example of an endotherm?

    <p>A mouse (D)</p> Signup and view all the answers

    What physiological response occurs in endotherms as environmental temperature decreases?

    <p>Increased metabolic rate and higher body temperature (C)</p> Signup and view all the answers

    Which among the following statements about heterothermic animals is true?

    <p>They can adjust their body temperature based on environmental influences. (A)</p> Signup and view all the answers

    What is a common characteristic of aquatic invertebrates regarding temperature regulation?

    <p>They show little ability to regulate their body temperature. (D)</p> Signup and view all the answers

    What is the primary method used to regulate physiological variables within a narrow homeostatic range?

    <p>Negative Feedback (B)</p> Signup and view all the answers

    Which of the following is NOT a factor that is regulated by homeostasis?

    <p>External environment (B)</p> Signup and view all the answers

    How does negative feedback help maintain homeostasis?

    <p>It opposes the change in the variable, bringing it back towards the set point. (B)</p> Signup and view all the answers

    If the body's temperature rises above the set point, what is the likely response of the homeostatic mechanisms?

    <p>Dilate blood vessels to increase heat loss. (B)</p> Signup and view all the answers

    Which of the following is an example of a homeostatic mechanism in action?

    <p>A runner's heart rate increasing during a race. (B)</p> Signup and view all the answers

    What is the difference between homeostasis and stability?

    <p>Homeostasis refers to a state of stable internal environment, while stability refers to a state of constant change within a tolerable range. (B)</p> Signup and view all the answers

    Which of the following is true about the set point of a homeostatic variable?

    <p>The set point can fluctuate within a narrow range. (D)</p> Signup and view all the answers

    Which of the following is NOT a strategy used to maintain homeostasis?

    <p>Genetic regulation (D)</p> Signup and view all the answers

    Flashcards

    Homeostasis

    Regulation of the body’s internal environment at stable levels despite external changes.

    Why is Homeostasis Necessary?

    To maintain optimal physiological performance by regulating temperature, nutrient levels, and waste concentration.

    Homeostatic Methods

    Mechanisms that regulate a physiological variable around a set point using feedback systems.

    Negative Feedback

    A process where a change in a variable triggers mechanisms to reverse that change.

    Signup and view all the flashcards

    Positive Feedback

    A process that amplifies changes by moving the variable further away from the set point.

    Signup and view all the flashcards

    Feedforward

    A mechanism that anticipates changes and initiates responses before the change occurs.

    Signup and view all the flashcards

    Set Point

    The ideal value for a physiological variable that the homeostatic system aims to maintain.

    Signup and view all the flashcards

    Physiological Variables

    Conditions such as temperature, pH, and ion concentrations that must be regulated for homeostasis.

    Signup and view all the flashcards

    Negative Feedback Mechanism

    A process that reduces differences between current state and set point to maintain homeostasis.

    Signup and view all the flashcards

    Endotherm

    An organism that generates heat from internal physiological processes.

    Signup and view all the flashcards

    Ectotherm

    An organism that relies on external sources to regulate body temperature.

    Signup and view all the flashcards

    Homeotherm

    An organism that maintains a constant body temperature regardless of the environment.

    Signup and view all the flashcards

    Heterotherm

    An organism whose body temperature varies with the environment.

    Signup and view all the flashcards

    Negative Feedback Loops

    Processes that reverse changes in body temperature to maintain homeostasis, such as sweating or panting.

    Signup and view all the flashcards

    Hypothalamus Role

    The brain region that integrates information to control body temperature through feedback mechanisms.

    Signup and view all the flashcards

    Physiological Responses

    Actions like blood flow changes and sweating that help regulate body temperature in response to environmental changes.

    Signup and view all the flashcards

    Thermoregulation

    The process by which animals maintain their body temperature within specific limits, despite external changes.

    Signup and view all the flashcards

    Study Notes

    Biol 224.3 - Animal Body Systems - Lecture 4: Homeostasis

    • Homeostasis is the regulation of the body's internal environment at a stable level, despite external changes.
    • Homeostatic mechanisms maintain a narrow range around a set point.
    • Internal environments (e.g., body temperature, nutrient concentration) are constantly being monitored and adjusted to maintain stable levels, even when external environments change significantly.
    • The goal of homeostasis is optimal physiological performance.
    • Homeostasis is necessary for all organisms to properly function.

    Road Map for Today

    • The lecture will cover:
      • What is homeostasis?
      • Why is homeostasis necessary?
      • Homeostatic methods
      • Thermoregulation

    Homeostasis

    • Definition: Regulation of the body's internal environment at or near a stable level, in response to external (large) changes.
    • External environment constantly changes, but homeostasis keeps internal environment relatively stable.

    Stability NOT Constancy

    • Homeostasis is about maintaining stability, not constancy.
    • For example, body temperature fluctuates during the day (diurnal rhythm).
    • This means that homeostasis operates within a range, adjusting to changes within that range.

    Why is Homeostasis Necessary?

    • Homeostasis is crucial for optimal physiological performance.
    • Maintaining specific concentrations of key substances (e.g., oxygen, CO2, nutrients, wastes, water, salts, pH) is essential.
    • Maintaining a stable temperature is required for enzyme function and cell structure/integrity.

    Homeostatic Methods

    • Homeostasis uses negative feedback loops as the primary method.
    • Sometimes positive feedback is needed for a short time in order to bring about a significant change (e.g., childbirth).
    • Feedforward mechanisms anticipate future changes in order to quickly react to them without waiting for a change to occur.

    Negative Feedback

    • A variable rises above the set point.
    • Negative feedback mechanisms return the variable towards the set point, minimizing any difference between the actual level and the set point.
    • This is the primary method of homeostasis.

    Positive Feedback

    • Used to quickly increase or decrease something.
    • Moves variable away from the set point.
    • An example is childbirth: strong uterine contractions result in increasing pain signals which result in greater contractions. The positive feedback is eventually shut off by a negative feedback loop.
    • Another example is the membrane potential (nerve action potential) in which a change in electrical potential causes a rapid change in potential.

    Positive Feedback Example: Childbirth

    • The brain triggers the release of oxytocin.
    • The strong uterine contractions stimulate the brain to release more oxytocin.
    • This cycle continues until the baby is born.

    Positive Feedback. Membrane Potentials

    • The rising phase of the nerve action potential is an example of positive feedback.
    • When a membrane reaches a certain potential, it greatly increases the rate at which it changes.

    Feedforward

    • Future needs are anticipated.
    • Physiological adjustments are made in advance.
    • Complex behaviours are often involved (e.g., a racehorse adjusting its breathing rate before starting a race).
    • Monarch butterflies (migration) is another example.

    Thermoregulation

    • Key terms include:
      • Endotherm vs Ectotherm
      • Homeotherm vs Heterotherm
    • Examples:
      • Endotherms
      • Ectotherms
    • Using negative feedback loops.

    Endotherm vs Ectotherm

    • Endotherm: Regulates internal body heat (e.g., mammals, birds).
    • Ectotherm: Gets heat from the external environment (e.g., reptiles, amphibians).

    Homeotherm vs Heterotherm

    • Homeotherm: Maintains a relatively constant internal temperature.
    • Heterotherm: Body temperature varies based on the environment.

    Endotherms vs Ectotherms:

    • Endotherms increase metabolic rate to maintain their temperature when external temperatures decrease.
    • Ectotherms often slow down bodily processes when external temperatures decrease.

    Questions

    • Advantages and disadvantages of being an endotherm.
    • Advantages and disadvantages of being an ectotherm.
    • Which is "superior"?
    • Are all endotherms homeotherms?
    • Examples of ectotherms in various invertebrate groups.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Lecture 4: Homeostasis - Biol 224.3 Animal Body Systems PDF

    Description

    This quiz covers Lecture 4 of Biol 224.3, focusing on the concept of homeostasis in animal body systems. Learn how organisms regulate their internal environments amidst external changes and explore methods of thermoregulation. Test your knowledge on the mechanisms that maintain physiological stability.

    More Like This

    Animal Coordination and Homeostasis Quiz
    5 questions

    Animal Coordination and Homeostasis Quiz

    EnergyEfficientMoose avatar
    EnergyEfficientMoose
    Homeostasis and Animal Body Organization
    29 questions

    Homeostasis and Animal Body Organization

    IntriguingGhost1564 avatar
    IntriguingGhost1564
    Homeostasis and Animal Body Organization
    29 questions

    Homeostasis and Animal Body Organization

    PeacefulRoseQuartz1513 avatar
    PeacefulRoseQuartz1513
    Homeostasis in Animal Physiology
    29 questions

    Homeostasis in Animal Physiology

    PeacefulRoseQuartz1513 avatar
    PeacefulRoseQuartz1513
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser