Components of blood

Plasma

The straw-coloured liquid component of blood that carries dissolved substances like glucose, amino acids, carbon dioxide, urea and hormones as well as blood cells.

Red blood cells

Biconcave disc cells containing haemoglobin that bind to oxygen and transport it from the lungs to tissues. They have no nucleus to fit more haemoglobin.

White blood cells

Cells involved in the immune system. Phagocytes engulf and digest pathogens; lymphocytes produce more antibodies and antitoxins.

Platelets

Small cell fragments without a nucleus that help blood clot at a wound site to prevent blood loss and pathogen entry.