2.7 Blood groups

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• Middelbare school
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• Leerjaar 2

2.7 Blood groups (transfusions)

Saving lives today!!

Red blood cells don't:

1. transport oxygen
2. transport glucose
3. transport carbon dioxide
4. transport haemoglobin

White blood cells don't:

1. produce antibodies
2. belong to the immune system
3. eat pathogens
4. transport oxygen

Why do we have white blood cells?

1. To protect us from suffocating
2. To protect us from bleeding out
3. To protect us from the cold
4. To protect us from pathogens

How do white blood cells know what to attack?

Cells have antigens on the outside of their cell membranes. White blood cells scan all the cells they meet to see if the antigens belong to your body. Antigens it doesn't recognise will be attacked.

Blood group A

Blood group B

Blood group AB

Blood group O

Antigen A

Antigen A

Antigen B

Antigen B

Antigen C

Antigen C

About how much blood does an adult human have circulating in their body?

What blood group is someone with antigen A?

1. A
2. B
3. AB
4. O

What blood group is someone with antigen A and B?

1. A
2. B
3. AB
4. O

What blood group is someone with neither antigen A nor B?

1. A
2. B
3. AB
4. O

How do white blood cells fight foreign antigens?

White blood cells produce antibodies. These are small molecules that can connect to antigens and each other. They can cover pathogens and stop them from causing harm. Because they also stick together they cause clots of pathogens and antibodies stuck together.

Antibodies and blood groups

Blood groups have different antigens, but also different antibodies. This is because they only have antibodies against antigens that are not the ones they have themselves.

The antibody against the rhesus factor is called anti-rhesus and can only be produced by people who are rhesus negative

Someone with antibody A and antibody B has blood group:

1. A
2. B
3. AB
4. O

Explain why you can't just give someone any type of blood with a blood transfusion

Figuring out someone blood group

When we need to give someone a blood transfusion we first need to know their blood group. We can do that by taking a bit of their blood and mixing it with antibodies to see if a reaction (clotting) takes place. Remember: antibody A clots with antigen A etc.

Example

In the left tube there is antibody A, but there is no clotting. Conclusion: No antigen A present

In the middle tube there is antibody B, there is clotting. Conclusion: antigen B present

Blood group: B

Finished!