Self And The Phenomenon Of Life: A Biologist Examines Life From Molecules To Humanity

The Animal Self: Molecular Recognition 111

“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity

Fig. 6.1. Blood type compatibility diagram. The arrows show how blood can be
donated from one person to another with different blood types. In blood transfusion,
it is the red blood cells from the donor that is of concern. Incompatibility results from
the reaction of the antibodies in the recipient’s serum toward the donor’s red cells. [See
Table 6.1 for further explanation.]

same blood group. In the business of transfusion, persons belonging to
the same blood type behave as if they were a collective self.^3
Another example of immunity is the defense against pathogens.
The world we live in is a very dangerous place, for we are threatened
not only by predators larger than us, but also by invisible microbial
pathogens lurking around, waiting for a chance to strike and consume us.
Without our knowing it, every cell in our body is constantly vigilant
of these tiny intruders. Historically, vaccination as a way to prevent

Table 6.1. Major Human Blood Types

Blood type name Group A Group B Group AB Group O

Antigens in red cell A B A&B None

Antibodies in serum Anti B Anti A None Anti A&B

Note: In transfusion, blood types are named after the antigens in red blood cell. A person’s

blood serum contains antibodies against antigens that his own red cells do not have, but

not against antigens that his own red cells have. Transfusion reaction occurs when the

recipient’s serum antibodies react against the red cells from an incompatible donor.