Feedback mechanism | Negative feedback | Positive feedback examples (Biology class 12)

#Feedback_mechanism_negative_feedback
#positive_feedback_examples
#Jiyas_Biology_Tutorials
Feedback mechanism
Feedback is defined as the information gained about a reaction to a product, which will allow the modification of the product. Feedback loops are therefore the process whereby a change to the system results in an alarm which will trigger a certain result. This result will either increase the change to the system or reduce it to bring the system back to normal.
Negative Feedback
A negative feedback loop occurs in biology when the product of a reaction leads to a decrease in that reaction. In this way, a negative feedback loop brings a system closer to a target of stability or homeostasis. Negative feedback loops are responsible for the stabilization of a system, and ensure the maintenance of a steady, stable state. The response of the regulating mechanism is opposite to the output of the event.
Example: Temperature Regulation
Temperature regulation in humans occurs constantly. Normal human body temperature is approximately 37°C. When body temperature rises above this, two mechanisms kick in the body begins to sweat, and vasodilation occurs to allow more of the blood surface area to be exposed to the cooler external environment. As the sweat cools, it causes evaporative cooling, while the blood vessels cause convective cooling. Normal temperature is regained. Should these cooling mechanisms continue, the body will become cold. The mechanisms which then kick in are the formation of goose bumps, and vasoconstriction. Goosebumps in other mammals raise the hair or fur, allowing more heat to be retained. In humans, they tighten the surrounding skin, reducing (slightly) the surface area from which to lose heat. Vasoconstriction ensures that only a small surface area of the veins is exposed to the cooler outside temperature, retaining heat. Normal temperature is regained.
Positive Feedback Loops
A positive feedback loop occurs in nature when the product of a reaction leads to an increase in that reaction. If we look at a system in homeostasis, a positive feedback loop moves a system further away from the target of equilibrium. It does this by amplifying the effects of a product or event and occurs when something needs to happen quickly.
Example: Childbirth (Labour pain)
When labor begins, the baby’s head is pushed downwards and results in increased pressure on the cervix. This stimulates receptor cells to send a chemical signal to the brain, allowing the release of oxytocin. This oxytocin diffuses to the cervix via the blood, where it stimulated further contractions. These contractions stimulate further oxytocin release until the baby is born.

[@meherkhan7316]

I never seen such a teacher who is teaching really in a amazing way. Thank you so much sir for clear my doubt.

[@ishmaltariq2651]

Mam there is mistake , Receptors cells receive stimulus not effectors..... Effectors are muscle cells where shivering non shivering procedure startup 😊

[@KhanOffecial-w9g]

Mam effecter cell doesn't receive stimulus but recepter done this job effecter make the change when recepter receive stimuli according to the body requirements 🙏🙏

[@KaitlynMassey]

Such a mesmerizing lecture 🌷🥰👌

[@THECODGHOSTYT]

Mam you made a mistake that receptors sense the change not effectors bcz effectors are the one which are responsible for action

[@JiyasBiologyTutorials]

Yes there is a mistsk i will make s new one on this topic

[@THECODGHOSTYT]

@@JiyasBiologyTutorials no problem its ok

[@junaidahmed9297]

Mam effector cells don't receive the stimuli but the receptors do this job😊

[@TakreemKhattak-r3o]

Very nice lecture thanks mam but mera 1 question hai ky positive feedback machanism mai destruction ata hai to per baby birth mai to ye destruction nahe howa ye tho faeda howa

[@JiyasBiologyTutorials]

It's a destruction because it gives pain to mother & hormones are released in positive feedback

[@SyedaZaidi-p3s]

​@@JiyasBiologyTutorials Dear not all the time positive feedback is destructive in our body some where is positive feed back is necessary for maintain homeostasis like blood clotting,during lactation and delivery It give pain at that time it is good for women due to that baby come out here it is not destructive . But mostly postive feed back not occur in ur body because it accelerate the function and it is not good for our body.

[@pkspatil2522]

👌👌

[@muhammadauranzaib7974]

so amazing teaching method

[@contactmeher6373]

love this channel and i really appreciate everything that you do.i

[@hafizshahkakar]

Thanks mam

[@adarshborkar2746]

Thankyou mam ❤️✨ 🤝 nyc ❤️🍫 lecture

[@muhammadmaaz6839]

🎉❤

[@sanaullahokz1639]

Nice

[@simranbajaj2234]

❤️❤️

[@SyedaZaidi-p3s]

There is big mistake my dear effector cells are muscle or gland that generate response and maintain homeostasis for receiving stimulus there is cells that are receptor that send info to the control center Good way of teaching but need some hard work too

[@syedaneesjan2388]

Help me ?

[@Gamiologist]

Starting change kr dijiye video jyada achi ho jaayegi yaa to kuch mat bolo ya to jai shree ram hi bol do

[@Jagruti556]

Sahi pakda!!