BLOOD

BLOOD TYPES AND BLOOD TRANSFUSIONS

Class Starter: 1) What are the different blood

types that exist?2) What determines what type of

blood you have?3) Why can you die if you were to

receive an incompatible blood type?

WHAT DETERMINES THE DIFFERENT BLOOD GROUPS?

Blood types are determined by the presence or absence of antigens on the surface of RBCs

A, B, Rh (Rhesus factor) = antigens (specific proteins) attached to RBCs

The different blood types are not spread out equally in the population

BLOOD TYPES

The presence or absence of a third antigen (Rh) determines if the blood type is positive or negative

Rh present = positive (+) Rh not present = negative (-)

This gives us 8 blood types: A-, A+, B-, B+, AB-, AB+, O-, O+

Blood Group Antigen

A+

A-

B+

B-

AB+

AB-

O+

O-

Blood Group

Antigen

A+ A, Rh

A- A

B+ B, Rh

B- B

AB+ A,B, Rh

AB- A, B

O+ Rh

O- none

BLOOD TRANSFUSIONS

People who have blood diseases and others who require extensive surgery must receive blood transfusions

A blood transfusion is the injection of blood into a person

This requires: a donor, the person who gives the blooda recipient, the person who receives the

blood

FACT: In the 19th century, many blood

transfusions resulted in the recipients dying.

Why? We know understand that there are specific

antibodies which circulate in a person’s blood

If a recipient’s antibodies match the donor’s antigens, the antibodies in the recipient’s blood will attack the donor’s antigens resulting in blood coagulation and possible death

ANTIBODIES

The antigens on your RBCs will determine the antibodies that circulate in your blood

The antibodies in your blood are the opposite of the antigens on your RBCs

BloodGroup

Antigens (surface)

Antibodies (in plasma)

A+ A, RhA- AB+ B, Rh

B- B,

AB+ A, B, RhAB - A, BO+ Rh

O - None

BloodGroup

Antigens (surface)

Antibodies (in plasma)

A+ A, Rh BA- A B, RhB+ B, Rh A

B- B, A, Rh

AB+ A, B, Rh None

AB - A, B Rh

O+ Rh A, B

O - None A, B, Rh

DRAW A PICTURE TO REPRESENT THE ANTIGENS AND ANTIBODIES PRESENT IN EACH BLOOD GROUP

Blood Group

Antigens

A+

A-

B+

B-

Blood Group

Antigens

AB+

AB -

O+

O -

BLOOD COMPATIBILITY RULES Main rule:

The donor’s blood cannot contain any antigens that match the antibodies on the recipients red blood cells

Tricks Similar blood types can always give blood to each other + blood types CANNOT give blood to – blood types – blood types CAN give blood to + blood types

Universal donors: can give blood to anyone = type O- (because it has no antigens)

Universal recipients: can receive blood from anyone = type AB+ (because it has no antibodies)

Blood Type

Can donate to: Can receive from:

A-A+B-B+AB-AB+O-O+

A

O ABB

HOW TO DETERMINE WHAT BLOOD TYPE A PERSON IS? A person’s blood group is determined by

mixing a drop of his or her blood with 3 different commercial serums (solutions with dissolved antibodies)

Anti-A serum Anti-B serum Anti-Rh serum

If agglutination (or coagulation) takes place, small dots appear. This means that the RBCs have antigens matching that specific serum. By determining which antigens are on the surface

of the RBCs we can deduce what the blood type is.

Example:

Blood sample X + anti-A serum = agglutination

Blood sample X + anti-B serum = no agglutination

Blood sample X + anti – Rh serum = no agglutination Sample X is blood type: A-

CREATING VACCINES WEB

PBS nova: BIO TERROR home page:

http://www.pbs.org/wgbh/nova/bioterror/

Creating a vaccine GAME: http://www.pbs.org/wgbh/nova/bioterror/vaccines.html