Transcript 11.1 Blood Antigens

11.1 Blood Antigens
Unit D – Human Systems
Antigens
 Antigens
are protein markers
found on the surface of cells.
 Act like an ID card
ANTIGENS CAN:
 stimulate
the formation of an
antibody
 be used to identify blood type.
 Example:
People with blood
antigen A have type A blood.
ABO Antigens
 Type
A blood has A antigens.
 Type B blood has B antigens.
 Type AB blood has A and B
antigens.
 Type O blood has no antigens.
What happens…
 If
you give one blood type to a
person with another blood
type?
 Blood Typing Animation
You can only give blood to a
different blood type when
 You
are blood type O
(Universal Donor)
You can only receive blood from a
different blood type when
 You
are blood type AB
(Universal Recipient)
Antibodies
 Produced
by your body in
response to foreign antigens.
 Form complexes with antigens
and signal the immune system to
clear and destroy cells attached
to antigens.
Rhesus Factor
Another antigen found on red blood cells.
 Individuals are referred to as “rhesuspositive” if they have rhesus factor antigen
on their red blood cells. (Rh+)
 Individuals are referred to as “rhesusnegative” if they lack rhesus factor antigen
on their red blood cells. (Rh-)

Agglutination
 Refers
to the clumping of blood
 occurs when antibodies are produced
in response to a “foreign” antigen.
 Agglutinated blood clogs blood
vessels, preventing oxygen and
nutrient delivery to cells.
Erythroblastosis fetalis
Problems can arise if Rh- individuals are
exposed to Rh+ blood.
 Specific problems occur when Rhmothers give birth to Rh+ babies. Rhmothers are exposed to baby’s Rh+ blood
during childbirth.
 Mother will start to make Rh+ antibodies.

In following pregnancies, Rh+ babies may
be exposed to antibodies against rhesus
factor when they cross the placenta.
 The Rh+ antibodies from the mother will
start to destroy the baby’s blood cells.
 The baby may suffer from deafness, brain
damage and death.

Information for Question
 Justin
has been in an accident.
 Justin has A+ blood.
1.
2.
3.
List the antigens found on the
surface of Justins blood cells.
Identify the antibodies that this
person could be producing.
List the blood types Justin could
receive blood from, if he is in need
of a blood transfusion.
4.
5.
If Justin wanted to be a blood donor,
what blood types could receive
blood from him?
If a patient receives blood that is
incompatible with his during a blood
transfusion, identify and describe the
problem that could arise.
Student Tasks for Lesson
 Complete
“Blood Typing
Practice” chart.
 Complete #10-18 on page
356.