PDF BLOOD PHYSIOLOGY - Mans

[Pages:28]BLOOD PHYSIOLOGY Lecture 3

BLOOD TYPES AND BLOOD TRANSFUSION

2nd year Dentistry 2008

1

Objectives

1. Describe the basis of blood typing

2. Know the ABO and Rh systems for blood typing and their clinical significance.

3. Describe incompatibilities in ABO and Rh systems.

4. Know the different types of blood transfusions and their complications (transfusion reactions).

5. Describe the basis of blood typing and cross matching tests for a safe blood transfusion.

2nd year Dentistry 2008

2

Basis of Blood grouping or Typing

(Multiplicity of Antigens in the blood cells)

? At least 30 commonly occurring antigens have been found on the cell membrane of RBCs.

? These can cause AgAb (antibody) reaction if mixed with plasma that contain Ab against these Ag.

? According to presence or absence of these antigens blood is classified into several groups or types.

? Two groups of Ag can cause transfusion reactions more than others: ABO and Rh systems of Ag.

2nd year Dentistry 2008

3

ABO System for Blood Typing A and B Antigens Agglutinogens

2nd year Dentistry 2008

4

ABO blood types

Relative frequency of different blood types:

? O

47%

? A

41%

? B

9%

? AB 3%

2nd year Dentistry 2008

5

Agglutinins (antibodies)

They are naturally occurring antibodies

Blood type

Agglutinogen on

RBC

Agglutinin in plasma

A

A

AntiB

B

B

AntiA

AB

A and B

None

O

None

AntiA and AntiB

2nd year Dentistry 2008

6

2nd year Dentistry 2008

7

Rh System for Blood Typing

? If type D antigen is present on RBC ? Rh +ve ? Differences between ABO and Rh Ab? ? AntiRh antibodies are not naturally occurring

Ab. ? Previous exposure to Rh antigen is required.

? Rh +ve blood transfusion. ? Rh ?ve women pregnant with Rh +ve baby.

? AntiRh Ab can cross the placenta.

2nd year Dentistry 2008

8

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download