Your body has two main communication systems - the nervous... Show more
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Responding to change (a2 only)
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0
Francesca๐ง
10/12/2025
Biology
the endocrine system
305
โข
10 Dec 2025
โข
Francesca๐ง
@francescastevens_pgeb
Your body has two main communication systems - the nervous... Show more

Think of hormones as your body's postal service - they're chemical messengers that travel through your blood to deliver important instructions to specific organs. Unlike the nervous system's lightning-fast signals, hormones work more slowly but have long-lasting effects on things like growth, mood, and metabolism.
Endocrine glands are the hormone factories scattered throughout your body. The pituitary gland acts like the boss, earning its nickname as the 'master gland' because it controls other glands and tells them when to release their hormones.
Some key players include the thyroid (which produces thyroxine to control your metabolism and heart rate), adrenal glands (which pump out adrenaline during stressful situations), and the pancreas (which makes insulin to manage blood sugar). In males, the testes produce testosterone, whilst in females, the ovaries create oestrogen for the menstrual cycle.
Quick Tip: Remember that hormones are like slow, steady controllers whilst nerves are like quick, precise switches - both are essential for keeping your body running smoothly!

Here's a simple way to work out whether your body is using nerves or hormones for a response. If something happens very quickly - like pulling your hand away from something hot - that's your nervous system in action because hormones are simply too slow for emergency situations.
However, if a response lasts for ages, you can bet it's hormonal. When you get a proper fright, adrenaline floods your system and activates 'fight or flight' mode - that's why you feel shaky and your heart pounds for ages afterwards.
The key differences are straightforward: nerves work incredibly fast, act for short periods, and target very specific areas. Hormones are slower to kick in, stick around much longer, and affect your body in a more general way. Both systems work together perfectly to keep you functioning properly.
Remember: Quick and precise = nerves; slow and long-lasting = hormones. This will help you ace any exam question about body responses!
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ all at your fingertips.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Francesca๐ง
@francescastevens_pgeb
Your body has two main communication systems - the nervous system and the endocrine system. The endocrine system uses chemical messengers called hormones to control processes that need constant adjustment throughout your body.

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Think of hormones as your body's postal service - they're chemical messengers that travel through your blood to deliver important instructions to specific organs. Unlike the nervous system's lightning-fast signals, hormones work more slowly but have long-lasting effects on things like growth, mood, and metabolism.
Endocrine glands are the hormone factories scattered throughout your body. The pituitary gland acts like the boss, earning its nickname as the 'master gland' because it controls other glands and tells them when to release their hormones.
Some key players include the thyroid (which produces thyroxine to control your metabolism and heart rate), adrenal glands (which pump out adrenaline during stressful situations), and the pancreas (which makes insulin to manage blood sugar). In males, the testes produce testosterone, whilst in females, the ovaries create oestrogen for the menstrual cycle.
Quick Tip: Remember that hormones are like slow, steady controllers whilst nerves are like quick, precise switches - both are essential for keeping your body running smoothly!

Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Here's a simple way to work out whether your body is using nerves or hormones for a response. If something happens very quickly - like pulling your hand away from something hot - that's your nervous system in action because hormones are simply too slow for emergency situations.
However, if a response lasts for ages, you can bet it's hormonal. When you get a proper fright, adrenaline floods your system and activates 'fight or flight' mode - that's why you feel shaky and your heart pounds for ages afterwards.
The key differences are straightforward: nerves work incredibly fast, act for short periods, and target very specific areas. Hormones are slower to kick in, stick around much longer, and affect your body in a more general way. Both systems work together perfectly to keep you functioning properly.
Remember: Quick and precise = nerves; slow and long-lasting = hormones. This will help you ace any exam question about body responses!
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ all at your fingertips.
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Smart Tools NEW
Transform this note into: โ 50+ Practice Questions โ Interactive Flashcards โ Full Mock Exam โ Essay Outlines
Explore the intricate workings of the Nervous and Endocrine Systems in this comprehensive summary. Understand key concepts such as homeostasis, reflex arcs, synaptic transmission, and hormonal control. This resource covers the roles of the Central Nervous System, the importance of blood glucose regulation, and the fight or flight response, making it essential for biology students preparing for exams.
Explore the mechanisms of homeostasis and hormonal regulation in the human body. This study note covers key concepts such as blood glucose control, the menstrual cycle, hormonal contraception, and the roles of the nervous and endocrine systems. Ideal for GCSE Combined Science students preparing for Biology Paper 2.
Explore the intricate systems of coordination and control in biology, including the nervous system, hormonal regulation, and the processes of aerobic and anaerobic respiration. This comprehensive study note covers key concepts such as the structure and function of the eye, synapses, neurons, and the role of the kidneys in homeostasis. Ideal for AQA and CCEA students preparing for exams.
Explore key concepts in biology focusing on homeostasis, hormonal coordination, and the structure and function of the eye. This comprehensive summary covers essential topics such as the nervous and endocrine systems, blood glucose regulation, and plant responses. Ideal for higher-tier students preparing for exams.
Explore the intricate systems of homeostasis and hormonal control in this comprehensive study note. Covering key concepts such as the menstrual cycle, nervous and endocrine systems, negative feedback mechanisms, and blood glucose regulation, this resource is essential for GCSE AQA Biology students. Understand how the body maintains stability through hormonal coordination and reflex actions.
Explore the essential mechanisms of homeostasis, including the regulation of internal conditions, enzyme functioning, and the role of negative feedback loops. This summary covers how control systems and receptors work together to maintain optimal body conditions, ensuring metabolic reactions function effectively. Ideal for students studying biology and physiology.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user