The diagram above is an approximation of what blood would look like when viewed on high power using a light microscope.

1) Plasma: Liquid portion of blood consisting of water, salts, & proteins. Function is to transport nutrients, carbon dioxide, hormones, urea and antibodies.

2) Erythrocytes (Red Blood Cells): Function is to transport oxygen.

3) Leukocytes (White Blood Cells): Function is defence.

a) lymphocytes: Control the immune response & make antibodies.

b) Phagocytes: Consume pathogens or diseased body cells via endocytosis.

4. Platelets: Fragments of white blood cells that circulate through the blood and function to form blood clots at sites of injuries.