Download Human Blood Types

Human Blood Types
The four basic blood types are identified by the presence of proteins called antigens A &
B in the Red Blood Cells & also antibodies in the plasma called Anti-A and Anti-B. It is
not possible to have the same type of antigen and antibody (E.g. Anti-A & A) in the same
person because the antibody will attack the RBCs and cause them to stick together
(clump). This clumping would block the circulation of blood.
Antigen – A Protein
Non-Clumped Blood
Blood cells are free floating, independent of one another in the
plasma. Blood flows easily through capillaries.
Clumped or Agglutinated
Red blood cells have stuck together to form agglutinations as they
are attacked by antibodies. Clumps block blood vessels.
Basic Blood Type
O
A
B
AB
Antigens in RBC
Neither
A
B
A and B
Antigens in Plasma
Anti-A & Anti-B
Anti-B
Anti-A
Neither
% of Population
46%
43%
8%
3%
Blood type is genetically, determined by the sequence of nucleotides in a person’s DNA
and control be changed after birth.
Rhesus (Rh) factor – each of the four major basic blood types is sub-divided into Rh
positive or Rh negative depending on the presence of the Rhesus protein inside the RBCs.
About 85% of the people in each basic group have the Rhesus protein and are therefore
said to be Rh+, 15% do not have the Rhesus factor and are said to be Rh-.
The most common blood type is O+ (38%), while the rarest blood type is AB 1%.
“O” Universal Donor
“AB” Universal Recipient
The Rh factor sometimes creates birth complications if a mother is Rh- while her baby is
Rh+ and leakage occurs at the placenta.