BLOOD 'N STUFF
Plasma
The liquid part of blood that carries nutrients and hormones throughout the body. It is mostly water, around 95% and contains dissolved proteins (6–8%). Plasma also serves as the protein reserve of the human body.
Platelets
These are cell fragments that assist in blood clotting. There are 300,000 platelets per microliter of blood.
Red Blood Cells
They are technically called Erythrocytes; Red blood cells are the most numerous type of blood cell. There are 5 million RBC per microliter of blood. RBCs have no nucleus.
White Blood Cells
WBC's are both a part of the circulatory system and the immune system. Technically called Leukocytes.