Parts of the blood Blood is the fluid

Parts of the blood Blood is the fluid circulating in the body that carries nutrients and oxygen, removes waste products and fights infection. • • Red Blood Cells Plasma White Cells Platelets

Red blood cells carry oxygen to the body’s organs and tissues. The inside of the red blood cell is filled with the protein haemoglobin.

Plasma Blood cells float in a strawcoloured liquid called plasma Plasma consist of water and many dissolved substances required in the body

White blood cells attack invading microbes that cause disease They do this in two ways: 1. One type of white blood cell produces chemicals called antibodies. These antibodies lock on to proteins called antigens on the surface of the microbes. 2. Another type of white blood cell digests any microbes the antibodies lock on to.

Platelets are • bits of cell broken off large cells They • help blood to clot • and stop bleeding at cuts.

Blood transfusions save lives everyday • One-off to replace a sudden loss of blood, e. g. following a serious accident, during surgery or childbirth, etc. • Ongoing to treat blood diseases like sickle cell anaemia or thalassaemia, or to treat cancer patients who survive their treatment. • Often transfusions are just of the part of the blood that the patient needs, e. g. red blood cells for sickle cell sufferers, whose own red cells are defective. • Medical breakthroughs like organ transplants increase the demand for donated blood.

Donating blood What’s so special about turning 17? At 17, if you are fit and healthy, you can donate blood. This is a ‘unit’ of blood, about 450 ml. Donate this much and you can help save lives. • Donated blood gets separated, and its four component parts can be used to help more than one patient in need. • So, even a single donation can help several people. • Imagine how many people a regular donor can help… But not everyone can donate to everyone…

Blood groups • • • There are four blood groups – A, B, AB and O Blood groups are classed as ‘positive’ with the presence of a particular antigen, ‘negative’ if it’s not there Your parents’ blood groups affect what group you belong to O is the only blood group that everyone can receive whatever group they belong to Some blood groups are more common among some ethnic communities Some ethnic communities are more likely to develop particular medical conditions that require blood donations

Blood groups in detail Blood group Group A: Group B: Group AB: Group O: Antigens You have certain proteins (called antigens) on the surface of your red blood cells: Has A antigens Has B antigens Has A and B antigens Has neither A nor B antigens Antibodies Your blood plasma contains certain antibodies which would attack red blood cell antigens that you do not have: Against B antigens – Anti. B Against A antigens – Anti-A Against no antigens Against A and B antigens – Anti-A, B Can donate to: Only those with antibodies that will NOT react with the antigens in the donated blood. e. g. Group A donor can only donate to recipients without Anti-A Can donate to Group A and Group AB Can donate to Group B and Group AB Can donate to all groups Can receive from: Only those whose antigens will NOT react with its own antibodies. e. g. Group A recipient can receive from anyone without B antigens. Can receive from Group A and Group O Can receive from Group B and Group O Can receive from all groups Can only receive from Group O