TOPIC 1.CLASSIFICATION KINGDOM FUNGI
Blood transfusion
In order for blood transfusion to be
successful, the blood of the donor and that of the recipient must mix without
agglutination. When this happens, the blood is said to be compatible. If the
blood is incompatible, agglutination occurs.
Blood compatibility depends on the
blood groups of the donor and the recipient. For example, if a person of blood
group A receives blood from a person of blood group B, the recipients’ body
produces antibodies against antigen B. This is because the antigen is seen as
foreign material.
Individuals with blood group AB are
called universal recipients. They can receive blood from people of any blood
group. However, they can only donate blood to someone with blood group AB.
Those with blood group O are universal donors. They can donate blood to people
of all blood groups. On the other hand, they can only receive blood from
someone with blood group O.
The following is a compatibility
table for the different blood groups.
Compatibility of blood groups
Donor's blood group Recipient's blood group
|
|
A
|
B
|
AB
|
O
|
|
A
|
√
|
×
|
√
|
×
|
|
B
|
×
|
√
|
√
|
×
|
|
AB
|
×
|
×
|
√
|
×
|
|
O
|
√
|
√
|
√
|
√
|
Key:
v - Means compatible
X - Means incompatible.
If blood from a rhesus positive
person is transfused to a rhesus negative person, the recipient produces rhesus
antibodies. If such a transfusion is done a second time, massive agglutination
can occur. This can lead to loss of life.
Precautions taken during transfusion
- Blood from the donor must be checked for compatibility with blood from the recipient in terms of both ABO blood group and Rhesus factor in order to avoid agglutination.
- The donor's blood must be screened to ensure that it does not have pathogens that can cause diseases such as HIV and AIDS, syphilis and hepatitis B.
- Donated blood is stored in special bags and an anticoagulant is added to prevent it from coagulating.
- Donated blood is kept in a refrigerator for a maximum of 21 days. After that it expires and should not be used.
- Transfusion should be done only when extremely necessary.
Advantages of blood transfusion
- It ensures rapid replacement of blood lost from the body, for example during surgery or due to an accident.
- Blood transfusion is used to treat diseases such as sickle-cell anaemia
Disadvantages of blood transfusion
- There are no exact blood matches. Blood is a complex tissue that contains many different. One person's blood cannot be exactly the same as another's. Hence, there are chances of developing a reaction to transfused blood.
- Transfused blood may not always be 100% free of infections.
Blood circulation in human being
Blood circulation is the movement of
blood from the heart to all part of the body and back to the heart. Human being
exhibit double circulation where by the blood passes through the heart
twice for each complete circulation
