Homeostasis and Negative/Positive Feedback

00:06:24
https://www.youtube.com/watch?v=Iz0Q9nTZCw4

Zusammenfassung

TLDRThe video explores biological organization and how the body maintains homeostasis—a state of balance for pH, glucose levels, and temperature—using positive and negative feedback systems. Negative feedback involves counteracting responses to stabilize conditions, such as sweating to cool down or shivering to warm up. Positive feedback amplifies changes, like the hormonal increase during childbirth that intensifies uterine contractions. The video also touches on type 1 diabetes to illustrate feedback disruption, where lack of insulin affects glucose uptake and cellular respiration. Examples of feedback systems in actions, such as temperature regulation and glucose balance, explain their critical role in maintaining homeostasis and understanding biological processes.

Mitbringsel

  • 🔄 Homeostasis is a key concept for body balance.
  • ❄️ Negative feedback helps regulate temperature.
  • ➕ Positive feedback amplifies biological processes.
  • 🌡️ The body uses sweating to cool down.
  • 🥶 Shivering warms the body by generating heat.
  • 🍬 Insulin is crucial for glucose uptake.
  • 🚼 Childbirth is a common example of positive feedback.
  • 🔍 Feedback systems help maintain stability.
  • ⚠️ Disruptions can lead to health issues like diabetes.
  • 🧠 Sensors and nerves play a role in feedback.
  • 🦎 Ectotherm vs. Endotherm: Different temperature regulation mechanisms.
  • 🔬 Learning feedback helps understand body disorders.

Zeitleiste

  • 00:00:00 - 00:06:24

    The video introduces the concept of homeostasis, highlighting its importance in maintaining a state of balance within the body through processes like managing blood pH, glucose levels, and internal temperature. Examples are given of how body systems work together through positive and negative feedback to achieve this balance. Negative feedback is exemplified by temperature regulation, where the body responds to heat by sweating and blood vessel dilation, and to cold by shivering and constricting blood vessels. Positive feedback is illustrated with childbirth, where hormone release leads to uterine contractions. The video also touches on the significance of understanding feedback mechanisms, using diabetes as an example of a feedback system malfunction.

Mind Map

Mind Map

Häufig gestellte Fragen

  • What is homeostasis?

    Homeostasis is the state of balance in the body's systems, maintaining variables like pH, glucose level, and body temperature within certain ranges.

  • What is negative feedback?

    Negative feedback is a process where a variable triggers a counteracting response to return to a set point, such as body temperature regulation.

  • What is positive feedback?

    Positive feedback amplifies a response to a variable, as in childbirth, where hormonal signals intensify uterine contractions.

  • Can negative feedback be disrupted?

    Yes, disorders like Type 1 diabetes can disrupt negative feedback, affecting glucose regulation due to the pancreas not producing insulin.

  • What role do sensors play in homeostasis?

    Sensors such as nerves detect changes in the environment, allowing the brain to initiate responses that maintain homeostasis.

  • How does the body respond to high temperatures?

    In high temperatures, the body cools down by sweating and dilating blood vessels to release heat.

  • Why is insulin important?

    Insulin helps cells take in glucose, essential for cellular respiration and energy production.

  • What happens during childbirth in terms of feedback?

    Childbirth is an example of positive feedback, where pressure on the cervix leads to more hormone release, causing more contractions.

  • What is an ectotherm and endotherm?

    An ectotherm, like a bearded dragon, adapts its body temperature to the environment, while an endotherm, like humans, regulates a stable internal temperature.

  • How do glucose levels affect homeostasis?

    Glucose levels are regulated by hormones like insulin and glucagon to maintain homeostasis, ensuring cells have necessary energy.

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Automatisches Blättern:
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    Captions are on! Click CC at bottom right to turn off.
  • 00:00:03
    You can follow the Amoebas on Twitter (@AmoebaSisters) and Facebook.
  • 00:00:06
    Did you know, just sitting here right now, you’re doing something absolutely remarkable?
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    Well you…your cells, tissues, organs, organ systems---yep we just leveled up those biological
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    levels of organization--- they’re all working towards something called homeostasis.
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    It’s a state of balance.
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    Yes, homeostasis means many things in your body: for example, that your blood stays within
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    a certain pH level range.
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    It means your blood glucose remains within a certain range.
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    It means your internal body temperature stays within a certain range.
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    See, we’ve mentioned the major body systems before, and that they work together---and
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    today we’re going to talk about HOW they work together---using something called positive
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    and negative feedback.
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    And, also, how this relates to homeostasis.
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    So many years ago, I had a pet bearded dragon.
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    Her name was Debbie and she was the best lizard ever.
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    Debbie used to sit on our couch with me when I’d watch TV.
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    And she loved to have her chin scratched.
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    I even got her a bearded dragon leash so I could take her outside…yeah, they make those…anyway,
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    Debbie loved her heat lamp.
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    She would sit under the heat lamp on her rock.
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    And when she got too hot, she would get off her rock and out of the heat lamp range and
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    go somewhere else.
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    She had a huge enclosure too because, I wanted Debbie to be a happy lizard, so she could
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    find an ideal temperature.
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    Well why all this talk about Debbie?
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    Well, Debbie is an example of an animal that some people refer to as cold-blooded.
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    Or a fancier term, ectotherm.
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    We actually like the fancier term a bit better though, because her blood isn’t necessarily
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    cold.
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    Her body temperature can fluctuate with the environment
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    But not you.
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    You are warm-blooded, or the fancier term, an endotherm.
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    Your body works hard to keep the internal temperature it keeps.
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    It’s also a beautiful example of something called negative feedback.
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    Before we define it---let us show you this example.
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    Say you are in an environment that is very hot.
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    Like…being outside in the Texas summer heat.
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    That’s typically hot.
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    Thanks to nerves which can act as sensors, the brain notices this.
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    It will send signals to counteract this variable.
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    Sweat glands do what they do best: sweat!
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    Heat is lost as that sweat evaporates off of your skin.
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    You may have some redness too---that’s because of your blood vessels are getting wider (dilating)---in
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    order to help get rid of that heat.
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    The result, whether you realize it or not, helps you lower your body temperature.
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    But wait!
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    What if you now go inside and the AC is blasting.
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    You will stop sweating.
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    You may even shiver.
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    The muscle contractions of shivering can generate heat.
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    And those blood vessels will now decrease in diameter size (constrict) to help you conserve
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    the heat because that makes it harder for heat to escape.
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    Your body temperature can increase then.
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    This is negative feedback.
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    So a simplified definition: negative feedback is when some variable triggers a counteracting
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    response---in order to come back to some set point.
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    If we consider that this whole thing is actually a negative feedback loop, we can see that
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    the negative feedback brings the body back to the set point, which in this case, is a
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    stable temperature. Keeping homeostasis.
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    Negative feedback is also going on in the regulation of your glucose (your blood sugar).
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    Ok we’re really simplifiying this here, as we often do, but when glucose (blood sugar)
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    is too high, one hormone that is released is insulin.
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    I always imagine insulin as this hormone that makes the cells say, “FEED ME!” because
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    it has the ability to make cells take in glucose.
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    On the flip side, if glucose is too low in the blood, a hormone called glucagon can be
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    released.
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    This hormone can have many effects and one of them is that it can cause the liver to
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    release glucose into the blood.
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    There’s more to the regulation of blood sugar than this but you can see how that’s
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    negative feedback---you have counteracting responses here in order to keep homeostasis.
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    So what about positive feedback?
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    Positive feedback is when, instead of getting a counteracting response to some variable,
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    you instead intensify the variable.
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    Positive feedback can be like “more more more” instead of “let’s counteract this.”
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    The example that always stuck with me when I was a student is the example about the human
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    human baby being born.
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    In biology classrooms everywhere, it’s a classic example.
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    When a human baby is ready to be born, there is pressure on the cervix.
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    And that pressure and the hormones involved cause contractions of the uterus---because
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    that’s a big part about how the baby is going to be born.
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    More release of hormones will equal more contractions and pressure which will cause more release
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    of hormones.
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    And more release of hormones will mean more contractions and pressure.
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    Contractions help get the baby out, but it’s also part of a beautiful illustration of what
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    positive feedback can do.
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    So why do we care about feedback?
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    Other then, you know, the importance of negative feedback in maintaining homeostasis and the
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    role of positive feedback in many body processes?
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    Well we also need to understand feedback so we can understand
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    what is happening when there is a problem in the feedback systems.
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    One example: perhaps you’ve heard of Type 1 diabetes.
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    It’s a disorder that can mean that your pancreas, which is an organ that is involved
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    with making some hormones like insulin, is not working correctly.
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    Insulin is not produced and, because of that, one issue is that you are not going to be able to get
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    glucose (the blood sugar) into your cells.
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    Glucose outside of the cells cannot be used in cellular respiration---the cells need to
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    take the glucose IN to make ATP energy in cellular respiration.
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    Therefore, your cells need to be able to take IN the glucose to survive.
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    So, many Type 1 diabetics need to give themselves insulin and monitor their blood sugar because
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    the negative feedback may not work as it should.
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    Well, that’s it for the Amoeba Sisters and we remind you to stay curious!
Tags
  • homeostasis
  • feedback
  • negative feedback
  • positive feedback
  • temperature regulation
  • glucose
  • insulin
  • type 1 diabetes
  • hormones
  • biology