Blood groups/ types

Question 1

what are the four main reasons someone may require a blood transfusion?

Answer 1

if a person is suffering from…

• excess blood loss
• anaemia
• leukaemia
• haemophilia

Question 2

define transfusion

Answer 2

the transfer of blood, or some of the components of blood, into the circulation of a person.

Question 3

the surface area of red blood cells is coated with…

Answer 3

sugar and protein molecules that are able to stimulate the immune system.

these molecules are called antigen and the proteins produced by the immune system is called an antibody.

Question 4

define antigen

Answer 4

any substance capable of causing the formation of antibodies when introduced into the tissue.

Question 5

define antibody

Answer 5

a substance produced in response to a specific antigen; it combines with the antigen to neutralise or destroy it.

Question 6

what are the two sugar antigens involved in ABO blood groups?

Answer 6

antigen A and antigen B

Question 7

how is a persons blood group determined?

Answer 7

by DNA and so is therefore inherited.

Question 8

when does a persons body produce antibodies?

Answer 8

a persons body is able to recognise their own antigens and will not produce antibodies for them. however, they will produce antibodies for antigens that are non-self.

Therefore a group A person can only produce antibody anti-B, a group B person can only produce antibody anti-A, a group AB person can produce neither and a group O person can produce both.

Question 9

what are Rh antigens

Answer 9

proteins

Question 10

Rh postive vs Rh negative

Answer 10

a person with Rh antigens is said to Rh positive; a person without Rh antigens is said to be Rh negative.

An individual without Rh antigens is able to produce an anti-Rh antibody that reacts against those antigens. Rh positive individuals cannot produce Rh antibody.

Question 11

what happens if incompatible blood types mix?

Answer 11

it will cause erythrocytes to clump together, or agglutinate.

if the receivers blood contains, or is able to make, antibodies against the antigens on the donors red blood cells, the foreign cells will clump together and disintegrate.

Question 12

types of transfusions

Answer 12

• whole blood
• red cell concentrates
• platelet concentrates
• cryoprecipitate
• immunoglobulins
• autologous transfusions

Question 13

who can blood group A donate to and who can they receive from?

Answer 13

donate to… A and AB

receive blood from… A and O

Question 14

who can blood group B donate to and who can they receive from?

Answer 14

donate to… B and AB

receive blood from… B and O

Question 15

who can blood group AB donate to and who can they receive from?

Answer 15

donate to… AB

receive blood from… A, B, AB, O

Question 16

who can blood group O donate to and who can they receive from?

Answer 16

donate to… A, B, AB, O

receive blood from… O

Question 17

whole blood transfusion

Answer 17

blood taken from the donor. it has a chemical added to prevent clotting. used mainly in cases of severe blood loss.

Question 18

red cell concentrates transfusion

Answer 18

the most widely used component of blood. made buy centrifuging whole blood to separate cells from plasma. used for patients suffering heart disease or anaemia.

Question 19

platelet concentrates transfusion

Answer 19

given to patients who have abnormal platelets or a reduced number of platelets.

Question 20

cryoprecipitate

Answer 20

obtained by freezing plasma and then thawing it. once plasma is thawed the cryoprecipitate remains solid, containing many of the substances required for blood clotting.

treats some forms of haemophilia, but used mostly for severe blood loss.

Question 21

immunoglobulins

Answer 21

group of proteins that act as antibodies. antibodies are extracted from plasma of suitable donors.

eg. tetanus immunoglobulin may be used to treat tetanus.

Question 22

autologous transfusion

Answer 22

when the patients own blood is used. blood is collected 4 weeks prior to an operation. they eliminate the effect of possible disease.