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88

Dec 20, 2025

3 pages

Understanding Blood Composition and Types

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Jada Green

@jadag2006

Blood is your body's vital transport system, carrying essential materials... Show more

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# Blood

Blood Transports:
- Oxygen: from lungs to body cells
- Carbon Dioxide: from body cells to lungs
- Nutrients: from digestive system

Blood Composition and Function

Ever wonder how oxygen gets from your lungs to your toes? Blood does that job! Blood transports oxygen from lungs to cells, carries carbon dioxide back to lungs, delivers nutrients from your digestive system, and removes waste products. It also distributes heat throughout your body and delivers hormones where they're needed.

Your blood consists of three main components in specific proportions. Plasma makes up about 55% of blood volume, red blood cells account for 45%, and white blood cells and platelets make up just 1%. Each component plays a crucial role in keeping you healthy.

Plasma is the light yellow fluid portion of blood that's 90% water. It carries nutrients, gases, hormones, and waste products through your bloodstream. It also contains clotting factors that help stop bleeding when you're injured.

Fun Fact: Red blood cells have a unique disk shape with a center indentation. This special shape increases their surface area, allowing them to absorb more oxygen. The darker your blood looks, the more oxygen it contains!

Erythrocytes (red blood cells) contain a complex protein called hemoglobin that binds to oxygen and carbon dioxide. These cells give blood its red color and are specially designed to maximize their oxygen-carrying capacity.

# Blood

Blood Transports:
- Oxygen: from lungs to body cells
- Carbon Dioxide: from body cells to lungs
- Nutrients: from digestive system

White Blood Cells, Platelets, and Blood Types

Your body has an army of defenders circulating in your blood! Leukocytes (white blood cells) act as your personal security team, with a normal count between 5,000-10,000 per microliter. These cells can actually squeeze through capillary walls to hunt down invaders in your tissues.

When white blood cells encounter pathogens, they destroy them through a process called phagocytosis. Think of them as pac-men, gobbling up bacteria and viruses to keep you healthy. This is why your white blood cell count often increases when you're fighting an infection.

Thrombocytes (platelets) are tiny cell fragments that spring into action when you're injured. When a blood vessel is damaged, platelets become sticky and clump together to form clots that stop bleeding. Without these tiny heroes, even small cuts could become dangerous.

Important: Blood types are determined by antigens (specific proteins) on your red blood cells. The ABO system classifies blood into four main types: A, B, AB, and O. Knowing your blood type is critical for safe blood transfusions!

Blood types matter because receiving the wrong type can cause a dangerous immune reaction. Type O is known as the "universal donor" since it lacks both A and B antigens, while type AB is the "universal recipient" because it can accept any blood type. Your blood type is inherited from your parents and stays the same throughout life.

# Blood

Blood Transports:
- Oxygen: from lungs to body cells
- Carbon Dioxide: from body cells to lungs
- Nutrients: from digestive system

Blood Type Compatibility

Blood transfusions can be lifesaving, but only if the blood types are compatible. The presence or absence of A and B antigens determines your blood type. Type O has neither antigen, while type AB has both.

The compatibility rules are crucial to remember. Type A blood can donate to types A and AB, but can only receive from types A and O. Type B follows similar rules, donating to types B and AB, while accepting only B and O. Type AB is the "universal recipient" that can accept any blood type but can only donate to other AB recipients.

Type O is considered the "universal donor" because it can donate to all blood types (A, B, AB, and O). However, people with type O blood can only receive type O blood themselves. This makes type O blood especially valuable in emergency situations when there's no time to check a patient's blood type.

Did you know? Besides the ABO system, another factor called the Rh factor (positive or negative) also affects compatibility. A positive Rh factor is much more common than negative, which is why hospitals are always especially grateful for donations from people with negative blood types!

Understanding blood type compatibility can help you appreciate why blood donations are so important. With only about 8% of the population having type O negative blood (universal donor), every donation matters.



We thought you’d never ask...

What is the Knowunity AI companion?

Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.

Where can I download the Knowunity app?

You can download the app in the Google Play Store and in the 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.

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

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

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

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

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

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

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

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

Paul T

iOS user

 

Health

88

Dec 20, 2025

3 pages

Understanding Blood Composition and Types

user profile picture

Jada Green

@jadag2006

Blood is your body's vital transport system, carrying essential materials to every cell and removing waste. This fluid makes up about 8% of your body weight and performs numerous life-sustaining functions. Understanding how blood works helps you appreciate one of... Show more

# Blood

Blood Transports:
- Oxygen: from lungs to body cells
- Carbon Dioxide: from body cells to lungs
- Nutrients: from digestive system

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 Composition and Function

Ever wonder how oxygen gets from your lungs to your toes? Blood does that job! Blood transports oxygen from lungs to cells, carries carbon dioxide back to lungs, delivers nutrients from your digestive system, and removes waste products. It also distributes heat throughout your body and delivers hormones where they're needed.

Your blood consists of three main components in specific proportions. Plasma makes up about 55% of blood volume, red blood cells account for 45%, and white blood cells and platelets make up just 1%. Each component plays a crucial role in keeping you healthy.

Plasma is the light yellow fluid portion of blood that's 90% water. It carries nutrients, gases, hormones, and waste products through your bloodstream. It also contains clotting factors that help stop bleeding when you're injured.

Fun Fact: Red blood cells have a unique disk shape with a center indentation. This special shape increases their surface area, allowing them to absorb more oxygen. The darker your blood looks, the more oxygen it contains!

Erythrocytes (red blood cells) contain a complex protein called hemoglobin that binds to oxygen and carbon dioxide. These cells give blood its red color and are specially designed to maximize their oxygen-carrying capacity.

# Blood

Blood Transports:
- Oxygen: from lungs to body cells
- Carbon Dioxide: from body cells to lungs
- Nutrients: from digestive system

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

White Blood Cells, Platelets, and Blood Types

Your body has an army of defenders circulating in your blood! Leukocytes (white blood cells) act as your personal security team, with a normal count between 5,000-10,000 per microliter. These cells can actually squeeze through capillary walls to hunt down invaders in your tissues.

When white blood cells encounter pathogens, they destroy them through a process called phagocytosis. Think of them as pac-men, gobbling up bacteria and viruses to keep you healthy. This is why your white blood cell count often increases when you're fighting an infection.

Thrombocytes (platelets) are tiny cell fragments that spring into action when you're injured. When a blood vessel is damaged, platelets become sticky and clump together to form clots that stop bleeding. Without these tiny heroes, even small cuts could become dangerous.

Important: Blood types are determined by antigens (specific proteins) on your red blood cells. The ABO system classifies blood into four main types: A, B, AB, and O. Knowing your blood type is critical for safe blood transfusions!

Blood types matter because receiving the wrong type can cause a dangerous immune reaction. Type O is known as the "universal donor" since it lacks both A and B antigens, while type AB is the "universal recipient" because it can accept any blood type. Your blood type is inherited from your parents and stays the same throughout life.

# Blood

Blood Transports:
- Oxygen: from lungs to body cells
- Carbon Dioxide: from body cells to lungs
- Nutrients: from digestive system

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 Type Compatibility

Blood transfusions can be lifesaving, but only if the blood types are compatible. The presence or absence of A and B antigens determines your blood type. Type O has neither antigen, while type AB has both.

The compatibility rules are crucial to remember. Type A blood can donate to types A and AB, but can only receive from types A and O. Type B follows similar rules, donating to types B and AB, while accepting only B and O. Type AB is the "universal recipient" that can accept any blood type but can only donate to other AB recipients.

Type O is considered the "universal donor" because it can donate to all blood types (A, B, AB, and O). However, people with type O blood can only receive type O blood themselves. This makes type O blood especially valuable in emergency situations when there's no time to check a patient's blood type.

Did you know? Besides the ABO system, another factor called the Rh factor (positive or negative) also affects compatibility. A positive Rh factor is much more common than negative, which is why hospitals are always especially grateful for donations from people with negative blood types!

Understanding blood type compatibility can help you appreciate why blood donations are so important. With only about 8% of the population having type O negative blood (universal donor), every donation matters.

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.

Where can I download the Knowunity app?

You can download the app in the Google Play Store and in the 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.

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

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

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

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

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

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

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

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

Paul T

iOS user