Blood is composed of plasma, red blood cells, white blood cells, and platelets. Plasma transports substances through the body and removes waste, while red blood cells carry oxygen through hemoglobin. White blood cells protect the body against infection and disease. Platelets help the blood to clot. There are four main blood groups - A, B, AB, and O - and compatibility between donor and recipient blood is important to avoid clotting. People with type O blood are universal donors and can donate to all groups, while those with type AB blood are universal recipients. Blood donation is important as blood cannot be manufactured and is needed for medical procedures, accidents, childbirth, and other illnesses. Donated blood is tested,

1. HUMAN
BLOOD

2. BLOOD CONSTITUENTS AND THEIR FUNCTION
PLASMA
• Pale yellowish liquid
• 90% water
• 10% soluble substances:
nutrients, mineral salts,
blood proteins, hormone
• Transports substances needed
by cells and removes waste
products from cells.
RED BLOOD CELLS
• No nucleus
• Biconcave disc-shaped
• Carry O2 in the form of
oxyhaemoglobin
BLOOD CELL & PLATELETS
WHITE BLOOD CELLS
• Have nucleus
• Irregular is shape
• Protect the body against
diseases and fight
infection
•
•
•
•
PLATELETS
small fragments of cells
Made in the bone marrow
No nucleus
Help in blood clotting

3. PLATELET
PLASMA
WBC
RBC

4. THE BLOOD GROUPS
A
B
AB
O
• Not all blood groups are compatible
• Blood transfusion is the transfer of blood
from a donor to a recipient
• Mixing incompatible blood groups leads to
blood clotting or agglutination, which is
dangerous for the recipient.

5. Donor-recipient compatibility
RECIPIENT
DONOR
A
B
A
AB
O
A
B
AB
O

6. O
AB
People with blood group O are called
universal donors because they can
donate to all blood groups.
People with blood group AB are called
universal recipients because they
can receive blood from all blood groups.

7. THE IMPORTANCE OF BLOOD DONATION
• Blood has no substitute and cannot be
manufactured synthetically.
• Blood is needed for surgery, the victims of
accidents and to treat patients with other
sicknesses and also during childbirth.

8. STORAGE & HANDLING DONATED BLOOD
HANDLING
• The donated blood is
tested for the blood
group.
• Then is screened for
diseases such as
hepatitis B and C, HIV or
sexually transmitted
diseases
•
•
•
•
•
STORAGE
May be stored as whole
blood or separated into
RBC, WBC, platelets or
plasma.
Collected in a plastic bag
which contains a
substance that prevent
coagulation.
Stored in blood banks at
4oC which can last for
about 40 days.
Fresh blood can last for
24 hours.
Before transfusion, the
bags are left at room
temperature for 2 hours.