Your body is like an incredibly complex machine made up... Show more
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Subjects
Classic Dramatic Literature
Modern Lyric Poetry
Influential English-Language Authors
Classic and Contemporary Novels
Literary Character Analysis
Romantic and Love Poetry
Reading Analysis and Interpretation
Evidence Analysis and Integration
Author's Stylistic Elements
Figurative Language and Rhetoric
Show all topics
Human Organ Systems
Cellular Organization and Development
Biomolecular Structure and Organization
Enzyme Structure and Regulation
Cellular Organization Types
Biological Homeostatic Processes
Cellular Membrane Structure
Autotrophic Energy Processes
Environmental Sustainability and Impact
Neural Communication Systems
Show all topics
Social Sciences Research & Practice
Social Structure and Mobility
Classic Social Influence Experiments
Social Systems Theories
Family and Relationship Dynamics
Memory Systems and Processes
Neural Bases of Behavior
Social Influence and Attraction
Psychotherapeutic Approaches
Human Agency and Responsibility
Show all topics
Chemical Sciences and Applications
Chemical Bond Types and Properties
Organic Functional Groups
Atomic Structure and Composition
Chromatographic Separation Principles
Chemical Compound Classifications
Electrochemical Cell Systems
Periodic Table Organization
Chemical Reaction Kinetics
Chemical Equation Conservation
Show all topics
Nazi Germany and Holocaust 1933-1945
World Wars and Peace Treaties
European Monarchs and Statesmen
Cold War Global Tensions
Medieval Institutions and Systems
European Renaissance and Enlightenment
Modern Global Environmental-Health Challenges
Modern Military Conflicts
Medieval Migration and Invasions
World Wars Era and Impact
Show all topics
292
•
30 Dec 2025
•
mia grace
@miagrace222
Your body is like an incredibly complex machine made up... Show more





Ever wondered what stops bacteria from invading your body every second of the day? The integumentary system is your personal bodyguard - it's made up of your skin, hair, nails, and all those tiny glands and nerves. This amazing barrier doesn't just keep nasties out; it also controls your body temperature when you're sweating in PE or shivering in winter.
Your skeletal system is basically your body's scaffolding. Without your 206 bones, cartilage, ligaments, and tendons, you'd be a wobbly mess on the floor! But bones do way more than just hold you up - they're actually factories that make your blood cells and storage units for important minerals.
The muscular system is what gets you moving, whether you're sprinting for the bus or just blinking your eyes. Your muscles attach to bones to create movement, but they're also working invisibly to keep your heart beating and your blood flowing around your body.
Quick Fact: Your heart is actually a muscle that never gets tired - it beats about 100,000 times every single day!

Think of your nervous system as your body's internet - it's constantly sending messages between your brain and every part of your body at lightning speed. Your brain and spinal cord act like the main control centre, receiving information from your senses and sending out commands to make you breathe, move, and think.
The endocrine system is your body's chemical messenger service, using hormones instead of electrical signals. These powerful chemicals, produced by glands like your thyroid, control everything from your growth spurts to your mood swings. They travel through your bloodstream, telling different parts of your body what to do and when to do it.
Your cardiovascular system is basically a massive delivery service running 24/7. Your heart pumps blood through thousands of miles of blood vessels, dropping off oxygen and nutrients to every cell whilst picking up waste products like carbon dioxide for disposal.
Did You Know? Your heart pumps about 5 litres of blood every minute - that's roughly 7,200 litres every day!

The lymphatic system is like having your own personal army fighting infections. This network of thin tubes and lymph nodes carries lymph fluid and white blood cells around your body, hunting down bacteria and other nasties whilst keeping your body's fluid levels balanced.
Every breath you take involves your respiratory system - a brilliant network that includes your airways, lungs, and blood vessels. This system's main job is swapping fresh oxygen for waste carbon dioxide, but it happens so automatically that you probably don't even think about the roughly 20,000 breaths you take each day.
Your digestive system is like a food processing factory that never stops working. Starting from your mouth and ending at your anus, this system includes your stomach, intestines, and helpful organs like your liver and pancreas. Together, they break down everything you eat into tiny particles your body can actually use for energy and growth.
Amazing Fact: Your small intestine is about 6 metres long but coiled up to fit inside you - if stretched out, it would be taller than a giraffe!

Your urinary system is basically your body's filtration plant, working non-stop to clean your blood and get rid of waste through urine. Your kidneys, ureters, bladder, and urethra work together to control your blood pressure, balance important chemicals, and maintain the right pH levels in your blood.
The reproductive system is designed for one ultimate purpose - creating the next generation of humans. In females, this includes the ovaries, fallopian tubes, uterus, cervix, and vagina, whilst males have the testes, prostate, and penis. These systems don't just make reproduction possible; they also produce hormones that affect everything from your voice changing to your growth patterns.
Understanding how these systems work together helps you appreciate just how amazing your body really is. Every system depends on the others - your muscles need oxygen from your respiratory system, your brain needs nutrients from your digestive system, and your immune system protects them all.
Mind-Blowing Truth: All 11 of these systems are working perfectly together right now as you read this, without you having to think about any of it!
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
mia grace
@miagrace222
Your body is like an incredibly complex machine made up of 11 different systems working together 24/7 to keep you alive and functioning. Each system has its own special job, from protecting you against germs to helping you move, think,... 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 what stops bacteria from invading your body every second of the day? The integumentary system is your personal bodyguard - it's made up of your skin, hair, nails, and all those tiny glands and nerves. This amazing barrier doesn't just keep nasties out; it also controls your body temperature when you're sweating in PE or shivering in winter.
Your skeletal system is basically your body's scaffolding. Without your 206 bones, cartilage, ligaments, and tendons, you'd be a wobbly mess on the floor! But bones do way more than just hold you up - they're actually factories that make your blood cells and storage units for important minerals.
The muscular system is what gets you moving, whether you're sprinting for the bus or just blinking your eyes. Your muscles attach to bones to create movement, but they're also working invisibly to keep your heart beating and your blood flowing around your body.
Quick Fact: Your heart is actually a muscle that never gets tired - it beats about 100,000 times every single day!

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 nervous system as your body's internet - it's constantly sending messages between your brain and every part of your body at lightning speed. Your brain and spinal cord act like the main control centre, receiving information from your senses and sending out commands to make you breathe, move, and think.
The endocrine system is your body's chemical messenger service, using hormones instead of electrical signals. These powerful chemicals, produced by glands like your thyroid, control everything from your growth spurts to your mood swings. They travel through your bloodstream, telling different parts of your body what to do and when to do it.
Your cardiovascular system is basically a massive delivery service running 24/7. Your heart pumps blood through thousands of miles of blood vessels, dropping off oxygen and nutrients to every cell whilst picking up waste products like carbon dioxide for disposal.
Did You Know? Your heart pumps about 5 litres of blood every minute - that's roughly 7,200 litres every day!

Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The lymphatic system is like having your own personal army fighting infections. This network of thin tubes and lymph nodes carries lymph fluid and white blood cells around your body, hunting down bacteria and other nasties whilst keeping your body's fluid levels balanced.
Every breath you take involves your respiratory system - a brilliant network that includes your airways, lungs, and blood vessels. This system's main job is swapping fresh oxygen for waste carbon dioxide, but it happens so automatically that you probably don't even think about the roughly 20,000 breaths you take each day.
Your digestive system is like a food processing factory that never stops working. Starting from your mouth and ending at your anus, this system includes your stomach, intestines, and helpful organs like your liver and pancreas. Together, they break down everything you eat into tiny particles your body can actually use for energy and growth.
Amazing Fact: Your small intestine is about 6 metres long but coiled up to fit inside you - if stretched out, it would be taller than a giraffe!

Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your urinary system is basically your body's filtration plant, working non-stop to clean your blood and get rid of waste through urine. Your kidneys, ureters, bladder, and urethra work together to control your blood pressure, balance important chemicals, and maintain the right pH levels in your blood.
The reproductive system is designed for one ultimate purpose - creating the next generation of humans. In females, this includes the ovaries, fallopian tubes, uterus, cervix, and vagina, whilst males have the testes, prostate, and penis. These systems don't just make reproduction possible; they also produce hormones that affect everything from your voice changing to your growth patterns.
Understanding how these systems work together helps you appreciate just how amazing your body really is. Every system depends on the others - your muscles need oxygen from your respiratory system, your brain needs nutrients from your digestive system, and your immune system protects them all.
Mind-Blowing Truth: All 11 of these systems are working perfectly together right now as you read this, without you having to think about any of it!
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.
7
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Comprehensive notes covering key topics in GCSE Biology, including cell division, genetics, evolution, and human biology. This guide aligns with the AQA specification and is useful for other exam boards. Detailed explanations and diagrams enhance understanding, making it an essential resource for effective revision. Note: Ecology is not included.
Explore the intricate mechanisms of hormonal control and homeostasis in the human body. This summary covers key concepts such as the roles of the adrenal and pituitary glands, blood glucose regulation, and the differences between Type 1 and Type 2 diabetes. Understand how the nervous and endocrine systems work together to maintain internal balance, featuring automatic control systems and reflex arcs. Ideal for biology students preparing for exams.
Explore the mechanisms of blood glucose regulation, focusing on the roles of insulin and glucagon produced by the pancreas. This summary covers how these hormones maintain normal blood sugar levels, the processes involved in storing and releasing glucose, and their significance in conditions like diabetes. Ideal for students studying human hormones and hormonal control.
Explore the essential roles of plant hormones in growth and responses to environmental stimuli, alongside the mechanisms of hormonal coordination in humans. This summary covers key concepts such as tropisms, the endocrine system, blood sugar regulation, and the importance of homeostasis in both plants and animals. Ideal for AQA Biology revision.
Explore key concepts of homeostasis and feedback mechanisms in biological systems. This summary covers essential topics such as negative feedback, biological growth, and response mechanisms, tailored for AQA Combined Science Paper 2 revision. Ideal for students preparing for exams.
Explore the key concepts of homeostasis, hormonal control, and the menstrual cycle in this comprehensive study resource. Understand the roles of the nervous and endocrine systems, blood glucose regulation, and various contraception methods. Ideal for GCSE Combined Science students preparing for exams.
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