Bone marrow and blood cells
The bone marrow is a spongy material that fills the middle of some bones and produces stem cells.
These are immature cells that develop into the three different types of blood cell:
red blood cells, which carry oxygen to all the cells in the body
white blood cells, which are essential for fighting infection
platelets, which help the blood to clot and control bleeding.
Plasma cells are a type of white blood cell. They are part of the immune system and help protect the body against infection. Plasma cells produce proteins known as antibodies (immunoglobulins). These antibodies circulate in the blood, ready to attack any viruses and bacteria present in the body.
If an infection occurs, more plasma cells are produced, creating more antibodies to attack whatever is causing the infection.
Antibodies are made up of proteins, which are linked together to make ‘chains’. Some are large protein chains known as ‘heavy’ chains and others are smaller chains known as ‘light’ chains.
There are five types of heavy chain (known as A, D, G, E and M), and two types of light chain (known as kappa and lambda). Antibodies each have one type of heavy chain and one type of light chain.