Open the App

Subjects

111

18 Dec 2025

2 pages

Biology Guide: Understanding Blood Components and Vessels

A

Aspyn B

@aspynb_ndem

Your blood is basically your body's transport system, carrying everything... Show more

# Biology REVISION 2

Organising plants + animals Blood

| Component       | Functions (s)
| --------------- | -----------------------------

Blood Components and Their Jobs

Ever wondered what's actually floating around in your bloodstream? Blood has four main components, each with a specific job that keeps you functioning.

Plasma is the liquid part that carries dissolved substances like carbon dioxide, digested food, urea, and hormones around your body. Think of it as your body's delivery service, transporting chemical messages and waste products wherever they need to go.

Red blood cells are your oxygen carriers, packed with haemoglobin that grabs oxygen in your lungs and delivers it to every cell. They're brilliantly designed - no nucleus means more space for haemoglobin, and their biconcave shape gives maximum surface area for gas exchange. Plus, they're small and flexible enough to squeeze through the tiniest blood vessels.

Quick Tip: Remember that red blood cells are thin to help diffusion happen faster - this design feature often comes up in exam questions!

White blood cells are your immune system's army. Phagocytes (70% of white cells) literally eat invading microorganisms through phagocytosis, whilst lymphocytes (25% of white cells) produce antibodies to fight off infections and diseases.

# Biology REVISION 2

Organising plants + animals Blood

| Component       | Functions (s)
| --------------- | -----------------------------

Platelets and Blood Vessels

Platelets might be tiny cell fragments, but they're lifesavers. Made in your bone marrow, they clump together at wounds and create proteins that cause blood clotting - basically your body's emergency repair kit to stop you bleeding out.

Your blood vessels form a massive transport network, with capillaries connecting the two main types. Arteries are the high-pressure motorways carrying oxygenated blood away from your heart (except the pulmonary artery). They need thick muscular walls and connective tissue for strength, plus a narrow lumen to maintain that crucial pressure.

Veins do the opposite job - they carry deoxygenated blood back to your heart (except the pulmonary vein) under much lower pressure. That's why they have thinner walls, less connective tissue, and a wider lumen to help blood flow back efficiently.

Exam Alert: The pulmonary artery and vein are exceptions to the usual rules - they often appear as trick questions, so remember them!

The whole system works because capillaries act as the connection points where gas and nutrient exchange actually happens between your blood and body tissues.



We thought you’d never ask...

What is the Knowunity AI companion?

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.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Most popular content: Blood

Most popular content in Biology

Most popular content

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

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

 

Biology

111

18 Dec 2025

2 pages

Biology Guide: Understanding Blood Components and Vessels

A

Aspyn B

@aspynb_ndem

Your blood is basically your body's transport system, carrying everything from oxygen to waste products around your body 24/7. Understanding how blood components and blood vessels work together is crucial for your biology exams and helps explain how your body... Show more

# Biology REVISION 2

Organising plants + animals Blood

| Component       | Functions (s)
| --------------- | -----------------------------

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

Blood Components and Their Jobs

Ever wondered what's actually floating around in your bloodstream? Blood has four main components, each with a specific job that keeps you functioning.

Plasma is the liquid part that carries dissolved substances like carbon dioxide, digested food, urea, and hormones around your body. Think of it as your body's delivery service, transporting chemical messages and waste products wherever they need to go.

Red blood cells are your oxygen carriers, packed with haemoglobin that grabs oxygen in your lungs and delivers it to every cell. They're brilliantly designed - no nucleus means more space for haemoglobin, and their biconcave shape gives maximum surface area for gas exchange. Plus, they're small and flexible enough to squeeze through the tiniest blood vessels.

Quick Tip: Remember that red blood cells are thin to help diffusion happen faster - this design feature often comes up in exam questions!

White blood cells are your immune system's army. Phagocytes (70% of white cells) literally eat invading microorganisms through phagocytosis, whilst lymphocytes (25% of white cells) produce antibodies to fight off infections and diseases.

# Biology REVISION 2

Organising plants + animals Blood

| Component       | Functions (s)
| --------------- | -----------------------------

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

Platelets and Blood Vessels

Platelets might be tiny cell fragments, but they're lifesavers. Made in your bone marrow, they clump together at wounds and create proteins that cause blood clotting - basically your body's emergency repair kit to stop you bleeding out.

Your blood vessels form a massive transport network, with capillaries connecting the two main types. Arteries are the high-pressure motorways carrying oxygenated blood away from your heart (except the pulmonary artery). They need thick muscular walls and connective tissue for strength, plus a narrow lumen to maintain that crucial pressure.

Veins do the opposite job - they carry deoxygenated blood back to your heart (except the pulmonary vein) under much lower pressure. That's why they have thinner walls, less connective tissue, and a wider lumen to help blood flow back efficiently.

Exam Alert: The pulmonary artery and vein are exceptions to the usual rules - they often appear as trick questions, so remember them!

The whole system works because capillaries act as the connection points where gas and nutrient exchange actually happens between your blood and body tissues.

We thought you’d never ask...

What is the Knowunity AI companion?

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.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

0

Smart Tools NEW

Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines

Mock Exam
Quiz
Flashcards
Essay

Similar content

Blood Cell Functions

Explore the essential roles of red blood cells, white blood cells, platelets, and plasma in the circulatory system. This summary covers haemoglobin's oxygen transport, immune defense mechanisms, and the components of blood crucial for clotting and nutrient transport.

BiologyBiology
11

Enzymes and Circulatory Systems

Explore the roles of enzymes in digestion, the structure and function of the circulatory system, and the processes of diffusion and osmosis. This summary covers key concepts such as blood components, enzyme experiments, and nutrient transport, providing a comprehensive overview for biology students.

BiologyBiology
11

Biology Concepts Overview

Explore key biological concepts including digestive enzymes, the circulatory system, gas exchange, and cell differentiation. This summary covers essential topics such as the structure and function of blood vessels, the role of enzymes in digestion, and the differences between communicable and non-communicable diseases. Ideal for students preparing for exams or seeking a comprehensive understanding of biology. Type: Summary.

BiologyBiology
11

Blood Composition Essentials

Explore the key components of blood, including plasma, red blood cells, white blood cells, and platelets. Understand their functions in oxygen transport, immune response, and clotting. This summary provides a concise overview for quick revision.

BiologyBiology
11

Biological Catalysts: Enzymes

Explore the role of enzymes as biological catalysts in chemical reactions. This summary covers enzyme structure, the active site, the lock and key model, and the induced fit model. Understand how enzymes lower activation energy and their specificity for substrates. Ideal for A-level Biology students seeking to grasp enzyme functionality and properties.

BiologyBiology
12

Red Blood Cell Functions

Explore the essential role of red blood cells in oxygen transport. This biology presentation covers their unique structure, including the presence of haemoglobin, the absence of a nucleus, and their biconcave shape, which maximizes oxygen absorption. Understand how these specialized cells navigate the bloodstream to deliver oxygen throughout the body.

BiologyBiology
11

Most popular content: Blood

Most popular content in Biology

Most popular content

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

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