1. Brainstorm a list of the things you know that are in your blood .

In a medical setting, the amount of substances in blood can be a key indicator to health or disease.
An average human has approximately 5L of blood. Inside this 5L are the cellular component and a liquid portion made
mostly of water, called plasma. The cellular component contains the red and white blood cells, as well as platelets that aid
in blood clotting. The remainder of the blood is plasma, containing all other dissolved nutrients such as glucose, ions and
proteins.
A centrifuge can be used to separate the cellular components from the plasma. The red blood cells would travel to the
bottom of the centrifuge tube and make up almost 45% of the blood. A measure of the percentage volume of whole blood
that is made up of red blood cells is called the haematocrit. The platelets (0.17%) and white cells (0.1%) would form a very
thin layer called the buffy coat and sit just on top of the red cells. The plasma would be at the top and would be about 55%
of the total blood volume.