Components of the blood

45% cells:

There are 3 cell types:

1. Erythrocytes
2. Leukocytes
3. Platelets

1. Erthrocytes 

• Contain haemoglobin (which have 4 haem groups)
• Quaternary protein
• Carries 4O2 molecules
• High SA:Volume ratio
• Only live 120 days due to lack of nucleus

2. Leukocytes

Can be split further into 2:

1. Granulocytes
2. Agranulocytes

1. Granulocytes:

There are 3 types of granulocytes:

1) Neutrophil

• Has a multi-lobed nucleus 
• Involved in phagocytosis

2) Basophil

• Histamine
• Heparin

3) Eosinophil

• Anti-histamine

2. Agranulocytes

There are 2 types of agranulocytes:

1) Monocytes

• Mature in tissues to become macrophages
• Involved in phagocytosis

2) Lymphocytes

• Release antibodies during the immune response

55% plasma:

This can be broken down into 3 main components:

1. Water (used as a solvent for the dissolved chemicals)
2. Hormones (insulin, glycogen)
3. Plasma proteins (antibodies, clotting proteins, enzymes)

It is also made up of inorganic ions (e.g. sodium ions), Glucose (source of energy for cells), Amino acids (allow cells to make proteins), urea (Excretory waste being transported to the kidney) and some dissolved gases (e.g. O2, CO2, N2).

Serum is the name given to plasma without the plasma proteins