Blood Typing Flashcards
In violent crimes, blood is often left on the crime scene or clothes. How does this help the investigation?
The blood can help to form evidence against the suspect or victim.
What is blood analysis?
Blood analysis is used to help confirm the presence or a suspect at the crime scene. It can be used to find an unknown victim.
What is found in blood?
Blood is used to transport materials around the body and to help prevent disease. You have about 5 litres of blood in your body.
What are the main components of blood?
- RED blood cells-to carry OXYGEN
- **WHITE **blood cells-to fight DISEASE
- PLASMA-to carry BLOOD CELLS, digested FOOD, WASTE (eg, carbon dioxide), HORMONES and ANTIBODIES.
- PLATELETS-fragments of cells to HELP the BLOOD to CLOT.
Are there more RED or WHITE blood cells in your BLOOD?
There are MANY more RED blood cells to white.
The ratio is about 600-700:1
Red blood cells are;
- small
- disclike shape that have no nucleus. This increses their surface area for carrying Oxyggen.
- contain haemoglobin (red pigment), that binds to OXYGEN
White blood cells are;
- large
- have a nucleus
Some white blood cells;
- Change shape so they can destroy microrganisms.
- Produce antibodies
Plasma:
- A straw-coloured liquid
- Mainly water (90%)
What is a blood group?
The type of blood you have is determined by your genes. The 4 blood types are;
A
B
AB
O
Blood types are determined by antigens. (protein mlecules) found on the surface of red blood cells.
What are the four antigens in each of the blood types?
- A - Contains A antigens
- B - Contains B antigens
- AB - Contains A and B antigens
- **O ** - Contains no antigens
What are the rough preportions of the different blood types in the UK?
- 44% O
- 42% A
- 10% B
- 4% AB
Why is it important to know your blood type if you are having a transfusion?
If you get the wrong type of blood your immune system will identify the antigens as being foreign and will produce antibodies to destroy them.
