In this post, we'll talk about homeostatis in I/GCSE Biology. Let's get started! 😆
Homeostatis
In I/GCSE Biology, it's commonly asked in the exam!
HOMEOSTATIS is the maintenance of a constant internal environment – It is achieved by balancing bodily inputs and outputs, using the NERVOUS SYSTEM and HORMONES to control the process. Examples if things that the body keeps the same are:
- Body temperature at 37˚C
- The amount of water inside our body
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/215328_120540.png)
Automatic control system
Automatic control systems throughout the body maintain a range of factors at steady levels and that this is required for cells to function properly.
For homeostasis to work, these control systems need to have:
- RECEPTORS to detect changes in the environment
- PROCESSING CENTRES to receive information and coordinate responses automatically
- EFFECTORS to produce the response
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/750171_303640.png)
Negative Feedback
In I/GCSE Biology, it's important the remember the following points!
NEGATIVE FEEDBACK ensures that, in any control system, changes are reversed and returned back to the set level.
For EXAMPLE:
- when receptors detect that the temperature in the body has increased above a certain level,
- the processing centre (brain) sends signals to the effectors (in this case sweat glands) to produce sweat to cool down the body.
- This process is where the steady state of the body is adjusted to reverse the change.
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/842929_434251.png)
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/702617_381101.png)
Osmoregulation
- For the cells of our body to work properly, it is important that their water contained is maintained at the correct level.
- This means our body must maintain a balance between the water we take in and water we lose
- Water is INPUT (gained) from drinks, foods and respiration and it is OUTPUT (lost) through sweating, breathing, faeces and the excretion of urine.
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/641936_961582.jpeg)
And we're done with this topic! Well Done!
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/125007_624778.png)
Drafted by Alyssa (Biology)
References:
- "4.4 Quiz Homeostasis", https://quizizz.com/_media/quizzes/e00d4e4f-2d95-477e-8f03-5e941e3ab6ed_900_900
- "Homeostasis", https://nitrocdn.com/BzukxzxIDWSkBjOuXIuFVkjjEriFmqlw/assets/static/optimized/rev-b8fe5f6/wp-content/uploads/2019/10/homeostasis-definition-768x432.jpg
- "Examples of Negative Feedback", https://assets.ltkcontent.com/images/8616/negative-feedback-loop_0066f46bde.jpg
- "Negative Feedback". Photo from the internet.
- "Osmoregulation", https://d20khd7ddkh5ls.cloudfront.net/homeostasis_osmoregulation_isotonic_hypertonic_hypotonic.jpg