Subjects
Maths
Biology
Chemistry
English Language
History
Responding to change (a2 only)
Infection and response
Homeostasis and response
Energy transfers (a2 only)
Cell biology
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)
Ecology
Cells
Show all topics
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
World war one
Britain: 1509 -1745
Show all topics
8
0
izzy
20/11/2025
PE
cardiovascular system
648
•
20 Nov 2025
•
izzy
@izzy_mac
Your cardiovascular system is basically your body's delivery service, constantly... Show more
Ever wondered why your heart pounds during a sprint? Your cardiovascular system has three main parts - the heart, blood, and blood vessels - all working together to keep your muscles supplied with what they need during physical activity.
Your heart works like a double pump with two separate circuits. The pulmonary circuit handles the "dirty" blood - deoxygenated blood flows from your right ventricle through the pulmonary artery to your lungs, gets cleaned up with fresh oxygen, then returns to your left atrium via pulmonary veins.
The systemic circuit delivers the goods to your body. Oxygenated blood shoots out from your left ventricle through the massive aorta, travels to all your muscles and organs, then returns as deoxygenated blood through the vena cava to your right atrium. It's like a perfectly timed relay race that never stops!
Quick Tip: Remember the circuits by thinking "Right = Respiratory" (pulmonary circuit starts from right side) and "Left = Life" (systemic circuit starts from left side to supply your whole body).
Think of blood vessels as a three-tier transport system, each designed for different jobs. Arteries are like motorways - they've got thick, muscular walls and narrow lumens because they handle high-pressure blood rushing away from your heart. Most carry oxygenated blood, except for those sneaky pulmonary arteries heading to your lungs.
Veins are more like country roads - they have thinner walls, wider lumens, and special valves to prevent blood from flowing backwards as it travels back to your heart under much lower pressure. Capillaries are the tiny back streets where all the real action happens - their walls are just one cell thick, allowing oxygen and nutrients to slip through to your tissues.
Each type of vessel is perfectly designed for its job. The thick, elastic artery walls can stretch and bounce back with each heartbeat, whilst the wide vein lumens make it easier for blood to flow back to your heart against gravity.
Your blood is like a busy transport network with different workers doing specific jobs. Red blood cells are the oxygen delivery drivers - they pick up oxygen from your lungs and drop it off at your muscles, then collect carbon dioxide waste for the return journey.
White blood cells act as your personal security team, fighting off infections and diseases that try to invade your body. Platelets are like emergency repair workers - when you get a cut, they rush to the scene and help your blood clot to stop the bleeding.
All these cells float around in plasma, which is basically the liquid motorway that carries everything through your bloodstream. Plasma also transports nutrients, hormones, and waste products around your body, making it essential for keeping everything running smoothly.
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.
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 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
izzy
@izzy_mac
Your cardiovascular system is basically your body's delivery service, constantly moving oxygen, nutrients, and waste products around through an amazing network of tubes and pumps. Understanding how your heart, blood vessels, and blood work together will help you grasp why... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered why your heart pounds during a sprint? Your cardiovascular system has three main parts - the heart, blood, and blood vessels - all working together to keep your muscles supplied with what they need during physical activity.
Your heart works like a double pump with two separate circuits. The pulmonary circuit handles the "dirty" blood - deoxygenated blood flows from your right ventricle through the pulmonary artery to your lungs, gets cleaned up with fresh oxygen, then returns to your left atrium via pulmonary veins.
The systemic circuit delivers the goods to your body. Oxygenated blood shoots out from your left ventricle through the massive aorta, travels to all your muscles and organs, then returns as deoxygenated blood through the vena cava to your right atrium. It's like a perfectly timed relay race that never stops!
Quick Tip: Remember the circuits by thinking "Right = Respiratory" (pulmonary circuit starts from right side) and "Left = Life" (systemic circuit starts from left side to supply your whole body).
Think of blood vessels as a three-tier transport system, each designed for different jobs. Arteries are like motorways - they've got thick, muscular walls and narrow lumens because they handle high-pressure blood rushing away from your heart. Most carry oxygenated blood, except for those sneaky pulmonary arteries heading to your lungs.
Veins are more like country roads - they have thinner walls, wider lumens, and special valves to prevent blood from flowing backwards as it travels back to your heart under much lower pressure. Capillaries are the tiny back streets where all the real action happens - their walls are just one cell thick, allowing oxygen and nutrients to slip through to your tissues.
Each type of vessel is perfectly designed for its job. The thick, elastic artery walls can stretch and bounce back with each heartbeat, whilst the wide vein lumens make it easier for blood to flow back to your heart against gravity.
Your blood is like a busy transport network with different workers doing specific jobs. Red blood cells are the oxygen delivery drivers - they pick up oxygen from your lungs and drop it off at your muscles, then collect carbon dioxide waste for the return journey.
White blood cells act as your personal security team, fighting off infections and diseases that try to invade your body. Platelets are like emergency repair workers - when you get a cut, they rush to the scene and help your blood clot to stop the bleeding.
All these cells float around in plasma, which is basically the liquid motorway that carries everything through your bloodstream. Plasma also transports nutrients, hormones, and waste products around your body, making it essential for keeping everything running smoothly.
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 key functions and components of the cardiovascular and respiratory systems, including blood circulation, gas exchange, and their roles in sports performance. This summary covers essential concepts such as heart anatomy, blood pressure, and the importance of red blood cells, providing a comprehensive understanding for students in human anatomy and physiology.
PEExplore the intricacies of the cardiovascular system, including the structure and function of the heart, blood vessels, and the processes of vasoconstriction and vasodilation. This summary covers key concepts such as the double circulatory system, cardiac output, and the role of hemoglobin in oxygen transport. Ideal for students studying biology and human anatomy.
PEExplore the key differences between aerobic and anaerobic exercise, including their energy systems, training methods, and benefits for cardiovascular health. This summary covers essential concepts in exercise physiology and physical education, highlighting effective training strategies such as HIIT, interval training, and continuous workouts.
PEExplore the essential components and functions of the cardiovascular system, including the heart's structure, the double-circulatory system, and the roles of arteries, veins, and capillaries. This summary is tailored for OCR GCSE PE students, highlighting key concepts such as heart rate, stroke volume, and cardiac output.
PEExplore the key functions of the cardiovascular and respiratory systems, including blood circulation, gas exchange, and the mechanics of breathing. This summary covers arteries, veins, capillaries, cardiac output, and the pathway of air during inspiration, providing essential insights for understanding human physiology.
PEExplore the key components of the skeletal system, including bone types, joint structures, and their functions in movement and protection. This summary covers the roles of bones in blood cell production, mineral storage, and muscle attachment, along with detailed descriptions of various joint types and their movements. Ideal for students studying human anatomy and physiology.
PEApp 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
