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Year 7 KS3

Blood runs through our entire body, but what is it?

Blood

Blood is a specialised fluid. It is made up of 4 main parts:

Red blood cells are specialised cells, which carry oxygen throughout the body.

They look like doughnuts without the whole. This shape is extremely important to their role in oxygen transport.

Hemoglobin is a specific protein inside red blood cells, which carries oxygen.

Mature red blood cells also loose their nucleus and mitochondria  

White blood cells are key components of the immune system.
Macrophages, Neutrophils, T cells, B cells etc.. Are forms of white blood cells.

Click here for more information on the immune system.

Platelets are an extremely important part of survival. They are involved blood clotting.

When platelets come across a cut, they bind to the damaged site and cause a blood clot.

While inactive they look like flat disks (plates). However once they are activated (by a macrophage) they grow tentacles and become extremely sticky.

Plasma is the fluid which all the above float in. It is the liquid portion of blood.

It accounts for roughly 55% of the blood in your system.

When we place the blood in a centrifuge we can separate its components via density.