Page 120 - Biology Form Two

Biology for Secondary Schools

Precautions taken during transfusion Disadvantages of blood transfusion
Blood from the donor must be checked (i) There are chances of developing
for compatibility with the blood from a reaction to transfused blood in
the recipient in terms of both ABO such a way that the patient’s blood
blood group and Rhesus factor to avoid destroys transfused blood. This
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agglutination. The donor’s blood must is because blood is a complex
be screened to ensure that it does not tissue that contains many different
have pathogens that can cause diseases substances. One person’s blood

such as hepatitis B, syphilis and AIDS. cannot be exactly the same as
another’s.
Donated blood is stored in special bags (ii) Transfused blood may cause
in a refrigerator and an anticoagulant is infections if it is not well screened.
added to prevent it from coagulating.
Transfusion should be done only when Blood circulation in human beings
extremely necessary.
Task 5.6
Advantages of blood transfusion Search the library or internet sources
(i) It ensures rapid replacement of for simulations or videos showing blood
blood lost from the body, for circulation in human being.
example during surgery, due to
an accident, or during and after Blood circulation is the movement of
delivery. blood from the heart to all parts of the

(ii) It is used to manage diseases such body and back to the heart, as shown in
as sickle-cell anaemia. Figure 5.13.

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