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1l the quest for political stability: germany, 1871-1991
Britain & the wider world: 1745 -1901
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
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Psychology
30 Nov 2025
466
2 pages
Ever wondered how your brain sends messages to the rest of your body in milliseconds? Neuronsare the... Show more
Your nervous system has three main types of neurons, each with a specific job. Sensory neurons carry messages from your body (like when you touch something hot) to your brain and spinal cord. Relay neurons act as connectors, linking sensory neurons to motor neurons or other relay neurons. Motor neurons then carry commands from your brain to muscles and glands, making you pull your hand away from that hot surface.
Each neuron has several key parts that work together brilliantly. The cell body contains the nucleus with all the genetic material, whilst dendrites branch out like tree limbs to receive signals from other neurons. The axon is like a highway that carries electrical impulses away from the cell body - it can be tiny or up to a metre long!
The myelin sheath wraps around the axon like insulation on electrical wire, protecting it and speeding up signal transmission. At the end of each axon are terminal buttons that communicate with the next neuron across a gap called a synapse.
Key Point When a neuron gets activated, the inside becomes positively charged, creating an electrical impulse that zooms along the axon - this is called "firing"!
Here's where it gets fascinating - whilst signals travel electrically within neurons, they switch to chemical communication between neurons. When that electrical impulse reaches the end of an axon, it triggers the release of neurotransmitters from tiny storage bags called synaptic vesicles.
These neurotransmitters are chemical messengers that float across the synapse to the next neuron. Each neurotransmitter has a unique shape that fits perfectly into specific receptor sites on the receiving neuron, like a key fitting into a lock. Once attached, they're converted back into electrical signals.
Neurotransmitters can have opposing effects on the receiving neuron. Excitatory neurotransmitters (like adrenaline) make the next neuron more likely to fire by increasing its positive charge. Inhibitory neurotransmitters (like serotonin) do the opposite - they make firing less likely by increasing negative charge.
The brain uses a clever process called summation to decide whether a neuron should fire. It literally adds up all the excitatory and inhibitory signals hitting a neuron - if excitatory signals win, the neuron fires; if inhibitory signals dominate, it stays quiet.
Remember This chemical communication system allows for incredibly precise control over every thought, movement, and emotion you experience!
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.
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Explore the mechanisms of synaptic transmission, including action potentials, neurotransmitter functions, and the roles of excitatory and inhibitory signals. This summary covers key concepts such as synapse structure, neurotransmitter types, and their impact on neuronal communication.
PsychologyThey look into neurotransmitters, what they do in the brain and how they function.
PsychologyBiological unit of ap psychology textbook
AP PsychologyUnit 2 review
PsychologyThese notes talk about neurons, resting vs. action potential, basic parts of the brain (including the lobes), and the nervous system.
PsychologyStudy guide on chapter 2, biopsychology, including the structure of the brain and neurons. Information was from the textbook Introduction to Psychology by Hawkes Learning and supplemented by my professor's resources.
PsychologyApp 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 it’s 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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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 it’s 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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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
Ever wondered how your brain sends messages to the rest of your body in milliseconds? Neuronsare the incredible communication network that makes everything from moving your hand to feeling emotions possible. Understanding how these cells work gives you insight... Show more
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Join milions of students
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Your nervous system has three main types of neurons, each with a specific job. Sensory neurons carry messages from your body (like when you touch something hot) to your brain and spinal cord. Relay neurons act as connectors, linking sensory neurons to motor neurons or other relay neurons. Motor neurons then carry commands from your brain to muscles and glands, making you pull your hand away from that hot surface.
Each neuron has several key parts that work together brilliantly. The cell body contains the nucleus with all the genetic material, whilst dendrites branch out like tree limbs to receive signals from other neurons. The axon is like a highway that carries electrical impulses away from the cell body - it can be tiny or up to a metre long!
The myelin sheath wraps around the axon like insulation on electrical wire, protecting it and speeding up signal transmission. At the end of each axon are terminal buttons that communicate with the next neuron across a gap called a synapse.
Key Point: When a neuron gets activated, the inside becomes positively charged, creating an electrical impulse that zooms along the axon - this is called "firing"!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Here's where it gets fascinating - whilst signals travel electrically within neurons, they switch to chemical communication between neurons. When that electrical impulse reaches the end of an axon, it triggers the release of neurotransmitters from tiny storage bags called synaptic vesicles.
These neurotransmitters are chemical messengers that float across the synapse to the next neuron. Each neurotransmitter has a unique shape that fits perfectly into specific receptor sites on the receiving neuron, like a key fitting into a lock. Once attached, they're converted back into electrical signals.
Neurotransmitters can have opposing effects on the receiving neuron. Excitatory neurotransmitters (like adrenaline) make the next neuron more likely to fire by increasing its positive charge. Inhibitory neurotransmitters (like serotonin) do the opposite - they make firing less likely by increasing negative charge.
The brain uses a clever process called summation to decide whether a neuron should fire. It literally adds up all the excitatory and inhibitory signals hitting a neuron - if excitatory signals win, the neuron fires; if inhibitory signals dominate, it stays quiet.
Remember: This chemical communication system allows for incredibly precise control over every thought, movement, and emotion you experience!
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 – all at your fingertips.
8
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the mechanisms of synaptic transmission, including action potentials, neurotransmitter functions, and the roles of excitatory and inhibitory signals. This summary covers key concepts such as synapse structure, neurotransmitter types, and their impact on neuronal communication.
PsychologyThey look into neurotransmitters, what they do in the brain and how they function.
PsychologyBiological unit of ap psychology textbook
AP PsychologyUnit 2 review
PsychologyThese notes talk about neurons, resting vs. action potential, basic parts of the brain (including the lobes), and the nervous system.
PsychologyStudy guide on chapter 2, biopsychology, including the structure of the brain and neurons. Information was from the textbook Introduction to Psychology by Hawkes Learning and supplemented by my professor's resources.
PsychologyApp 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 it’s 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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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 it’s 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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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
