Blood and Bodily Fluids
Friday, 18th March 2022
Blood:
Defined by the ABO and Rh factors.
Under this, there are 32 blood types.
This system is shared by all primates.
Discovered by Landsteiner in Vienna circa. 1900.
Some patients who got blood transfusions died and others did not.
ABO follows non-Mendelian patterns of inheritance.
ABO Groups:
Type A RBCs have A antigens, type B
have B antigens, AB has both A and B
antigens, while O lacks all antigenic
markers on their RBCs.
All RBCs have carbohydrate sections on their cell membrane (glycoproteins).
A,B and O have the same skeleton (N-acetylgalactosamine→galactose→N-
acetylglucosamine→galactose-fructose).
A has another N-acetylgalactosamine while B has another galactose sugar.
O has no sixth sugar.
Alleles correlating to this system are the I^A (A group), I^B (B group) and I (O
group), with A and B being co-dominant while O is recessive to both.
The different alleles determine which extra sixth sugar is added (or if no
sugar is added).
Blood and Bodily Fluids 1
, Thus our possible genotypes include:
ii → O group | iI^A → A group | iI^B → B group | I^AI^A → A group |
I^BI^B → B group | I^AI^B → AB group
Antigens and Antibodies:
The antigens on your own blood cells are recognised as self.
If foreign antigens are recognised
by immune cells, antibodies against
the foreign RBCs will be made by
plasma cells.
These antibodies will coagulate
foreign blood leading to clotting.
The paratope on the antibody matches the epitope of the antigen.
If non-joining and non-self recognition occurs, agglutination occurs and leads
to the clumping of foreign RBCs.
A phenotypes produce anti-B antibodies, B phenotypes produce anti-A
antibodies, AB phenotypes do not produce antibodies while type O phenotype
produces anti-A and anti-B antibodies.
If an A receptor receives B donor, agglutination occurs and vice verse.
A and B will react with AB blood since they have antibodies against
either antigens.
AB can receive blood from anyone as it has no antibodies to react.
O can only receive blood from another O as it has antibodies against any
other blood type.
This means AB is the universal acceptor while O is the universal donor.
Rh Factor:
Also known as the “D antigen”.
Unlike ABO, it does follow Mendelian patterns of inheritance.
The RR and Rr genotype give the Rh+ phenotype.
The rr genotype gives the Rh- phenotype.
Blood and Bodily Fluids 2
Friday, 18th March 2022
Blood:
Defined by the ABO and Rh factors.
Under this, there are 32 blood types.
This system is shared by all primates.
Discovered by Landsteiner in Vienna circa. 1900.
Some patients who got blood transfusions died and others did not.
ABO follows non-Mendelian patterns of inheritance.
ABO Groups:
Type A RBCs have A antigens, type B
have B antigens, AB has both A and B
antigens, while O lacks all antigenic
markers on their RBCs.
All RBCs have carbohydrate sections on their cell membrane (glycoproteins).
A,B and O have the same skeleton (N-acetylgalactosamine→galactose→N-
acetylglucosamine→galactose-fructose).
A has another N-acetylgalactosamine while B has another galactose sugar.
O has no sixth sugar.
Alleles correlating to this system are the I^A (A group), I^B (B group) and I (O
group), with A and B being co-dominant while O is recessive to both.
The different alleles determine which extra sixth sugar is added (or if no
sugar is added).
Blood and Bodily Fluids 1
, Thus our possible genotypes include:
ii → O group | iI^A → A group | iI^B → B group | I^AI^A → A group |
I^BI^B → B group | I^AI^B → AB group
Antigens and Antibodies:
The antigens on your own blood cells are recognised as self.
If foreign antigens are recognised
by immune cells, antibodies against
the foreign RBCs will be made by
plasma cells.
These antibodies will coagulate
foreign blood leading to clotting.
The paratope on the antibody matches the epitope of the antigen.
If non-joining and non-self recognition occurs, agglutination occurs and leads
to the clumping of foreign RBCs.
A phenotypes produce anti-B antibodies, B phenotypes produce anti-A
antibodies, AB phenotypes do not produce antibodies while type O phenotype
produces anti-A and anti-B antibodies.
If an A receptor receives B donor, agglutination occurs and vice verse.
A and B will react with AB blood since they have antibodies against
either antigens.
AB can receive blood from anyone as it has no antibodies to react.
O can only receive blood from another O as it has antibodies against any
other blood type.
This means AB is the universal acceptor while O is the universal donor.
Rh Factor:
Also known as the “D antigen”.
Unlike ABO, it does follow Mendelian patterns of inheritance.
The RR and Rr genotype give the Rh+ phenotype.
The rr genotype gives the Rh- phenotype.
Blood and Bodily Fluids 2
