Describe the composition of blood

Blood is a specialized body fluid made up of four main components:
1. Plasma
The liquid part of blood that is made up of mainly  water
Carries many dissolved substances such as:
Nutrients (glucose, amino acids)
Hormones
Proteins (albumin, globulins, fibrinogen)
Waste products 
2. *Red Blood Cells (Erythrocytes)*
Contain hemoglobin, a protein that carries oxygen.
Transport oxygen from the lungs to body tissues and carbon dioxide back to the lungs.
They give blood its red color.
3. *White Blood Cells (Leukocytes)*
Part of the immune system.
Help fight infections and foreign substances such as bacteria, viruses, and parasites.
There are two types called Lymphocytes and Phagocytes 
4. *Platelets (Thrombocytes)*
Small cell fragments.
Help in blood clotting to stop bleeding when blood vessels are injured.