Subjects
Maths
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Biology
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Responding to change (a2 only)
Infection and response
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Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
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
World war one
Britain: 1509 -1745
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Biology
13 Dec 2025
100
2 pages
Kiana Coheh @kianacoheh_fdcp
Your heart is basically a powerful pump that keeps you alive by pushing blood around your entire body... Show more
Think of your heart as a four-room house with a clever traffic system. The four chambers work in pairs two atria at the top (right and left atrium) and two ventricles at the bottom (right and left ventricle).
Here's how the blood journey works deoxygenated blood from your body enters the right atrium through the vena cava, then flows down to the right ventricle. Meanwhile, oxygenated blood from your lungs enters the left atrium via the pulmonary vein, then moves to the left ventricle.
Heart valves are like one-way doors that prevent blood from flowing backwards. The tricuspid valve sits between the right atrium and ventricle, whilst the bicuspid valve does the same job on the left side. Semi-lunar valves guard the exits where blood leaves the heart through the pulmonary artery and aorta.
Key Point The right side of your heart deals with deoxygenated blood going to the lungs, whilst the left side handles oxygenated blood going to the rest of your body.
Coronary heart disease (CHD) happens when fatty deposits called atheroma build up in your coronary arteries - the blood vessels that feed your heart muscle. These deposits form plaques that narrow the artery, reducing blood flow and potentially causing heart attacks.
When heart valves go wrong, you get two main problems stiff valves that won't open properly, or leaky valves that let blood flow backwards. Both make your heart work harder and can cause breathlessness. Doctors can replace damaged valves with biological valves (from animals or donors) or mechanical valves.
Modern medicine offers brilliant solutions for heart problems. Stents are tiny tubes inserted into blocked arteries to keep them open - they're highly successful and last ages. Artificial pacemakers fix irregular heartbeats by sending electrical signals to your heart, taking over from your natural pacemaker (a group of cells in the right atrium).
Remember Your heart has its own built-in electrical system, but sometimes it needs a bit of technological help to keep the rhythm steady!
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential roles of phloem and xylem in plant biology. This summary covers the structure and function of these vascular tissues, the process of translocation and transpiration, and the factors affecting transpiration rates. Ideal for students studying plant physiology and anatomy.
BiologyExplore the organization of plant cells, including vascular tissues like xylem and phloem, and their roles in nutrient transport and photosynthesis. This summary covers key concepts such as transpiration, stomata function, and the impact of environmental factors on plant health. Ideal for GCSE Biology revision.
BiologyExplore the organization of plant cells, including detailed descriptions of various plant tissues such as xylem, phloem, and mesophyll. Understand how these tissues function in leaf anatomy and contribute to plant survival and growth. This summary is ideal for students studying plant biology.
BiologyExplore the intricacies of cell specialisation and the hierarchical organisation of tissues and organs in multicellular organisms. This summary covers key concepts such as tissue types, organ systems, and the role of cell differentiation, tailored for AQA A-level Biology students.
BiologyExplore the concept of diffusion in this concise summary, perfect for Year 9-10 biology students. Learn about high and low concentration areas, concentration gradients, and real-life examples like perfume dispersal. This resource is ideal for revision and understanding key biological processes.
BiologyExplore key concepts in GCSE AQA Biology Paper 1, including cellular structure, functions, photosynthesis, and respiration. This summary provides a clear understanding of essential topics for exam preparation.
BiologyQuotes from every main character
English LiteratureApp 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
Kiana Coheh
@kianacoheh_fdcp
Your heart is basically a powerful pump that keeps you alive by pushing blood around your entire body 24/7. Understanding how this amazing organ works and what can go wrong with it is crucial for your biology studies and for... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Think of your heart as a four-room house with a clever traffic system. The four chambers work in pairs: two atria at the top (right and left atrium) and two ventricles at the bottom (right and left ventricle).
Here's how the blood journey works: deoxygenated blood from your body enters the right atrium through the vena cava, then flows down to the right ventricle. Meanwhile, oxygenated blood from your lungs enters the left atrium via the pulmonary vein, then moves to the left ventricle.
Heart valves are like one-way doors that prevent blood from flowing backwards. The tricuspid valve sits between the right atrium and ventricle, whilst the bicuspid valve does the same job on the left side. Semi-lunar valves guard the exits where blood leaves the heart through the pulmonary artery and aorta.
Key Point: The right side of your heart deals with deoxygenated blood going to the lungs, whilst the left side handles oxygenated blood going to the rest of your body.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Coronary heart disease (CHD) happens when fatty deposits called atheroma build up in your coronary arteries - the blood vessels that feed your heart muscle. These deposits form plaques that narrow the artery, reducing blood flow and potentially causing heart attacks.
When heart valves go wrong, you get two main problems: stiff valves that won't open properly, or leaky valves that let blood flow backwards. Both make your heart work harder and can cause breathlessness. Doctors can replace damaged valves with biological valves (from animals or donors) or mechanical valves.
Modern medicine offers brilliant solutions for heart problems. Stents are tiny tubes inserted into blocked arteries to keep them open - they're highly successful and last ages. Artificial pacemakers fix irregular heartbeats by sending electrical signals to your heart, taking over from your natural pacemaker (a group of cells in the right atrium).
Remember: Your heart has its own built-in electrical system, but sometimes it needs a bit of technological help to keep the rhythm steady!
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential roles of phloem and xylem in plant biology. This summary covers the structure and function of these vascular tissues, the process of translocation and transpiration, and the factors affecting transpiration rates. Ideal for students studying plant physiology and anatomy.
BiologyExplore the organization of plant cells, including vascular tissues like xylem and phloem, and their roles in nutrient transport and photosynthesis. This summary covers key concepts such as transpiration, stomata function, and the impact of environmental factors on plant health. Ideal for GCSE Biology revision.
BiologyExplore the organization of plant cells, including detailed descriptions of various plant tissues such as xylem, phloem, and mesophyll. Understand how these tissues function in leaf anatomy and contribute to plant survival and growth. This summary is ideal for students studying plant biology.
BiologyExplore the intricacies of cell specialisation and the hierarchical organisation of tissues and organs in multicellular organisms. This summary covers key concepts such as tissue types, organ systems, and the role of cell differentiation, tailored for AQA A-level Biology students.
BiologyExplore the concept of diffusion in this concise summary, perfect for Year 9-10 biology students. Learn about high and low concentration areas, concentration gradients, and real-life examples like perfume dispersal. This resource is ideal for revision and understanding key biological processes.
BiologyExplore key concepts in GCSE AQA Biology Paper 1, including cellular structure, functions, photosynthesis, and respiration. This summary provides a clear understanding of essential topics for exam preparation.
BiologyQuotes from every main character
English LiteratureApp 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
Sociology