Blood
Function of Blood
Composition of Blood
Blood Types
Function of Blood
Transport
of:
Oxygen
Carbon Dioxide
Nutrients
Wastes
Immunity
Composition Of
Blood
 55
% Plasma
 45%
Cells and Cell Parts
Plasma


composed of:
– clear golden fluid and Water
– dissoved substances
– proteins
Has several functions:
– Transports small molecules and ions
– contains proteins involved in blood clotting
– contains antibodies that are involved in disease
fighting
Blood Cells and
Cell Parts
There are 3 Cellular components to blood
 Red Blood Cells
 White Blood Cells
 Blood Platelets
Red Blood Cells
Also called Erythrocytes
 Main function is to carry Oxygen
 Structure:

– Mature cells do not contain a nucleus
– Cytoplasm contains a molecule called
Hemoglobin
The function of hemoglobin is to carry oxygen
 every R.B.C contains > 200 mil. hemoglobin
molecules

White Blood Cells
also called Leucocytes
 Function: protect the body from
infection
There are Two main types of W.B.C. s
 macrophages

– move out of capp. and digest foriegn
materials by phagocytosis

Lymphocytes
– manufacture antibobies that fight infection
Platelets
Cell fragments
 250 million per cubic centimetre
 Function: Trigger the Blood Clotting
Process

Review of Blood
Components
Blood
Plasma
Blood Cells and Blood Parts
White Blood Cells(W.B.C)
-Leucocytes
Macrophages
Lymphocytes
Platelets
Red Blood Cells (R.B.C)
-Erththrocytes
Important Terms
Antigen
 Molecules that cause
the synthesis of
antibodies when
injected into another
organism
Antibody
 Proteins found in
blood that attack
and neutralize
substances that are
foreign to the body
Major Blood Groups
Discovered by Karl Landsteiner
 Different blood groups are due to
differing antigens present on red cell
membranes
 4 Major Blood Types

–
–
–
–
A
B
AB
O
BLOOD TRANSFUSIONS
Not all blood types can be mixed
together
 If the wrong Blood types are mixed a
process called Agglutination will occur

Agglutination - the clumping of blood

Examine the next chart to see
compatible blood groups
Blood Compatibilities
Blood Type
Antigen
Antibody
A
A
Anti B
B
B
Anti A
AB
A and B
None
O
None
Anti A and
Anti B
Rh Factors
Other antigens that may be present on
R. B C. s
 Most people have these antigens they
are said to be Rh Positive
 Those without the antigen are said to be
Rh Negative

Rh Factors and Pregancy
Problems may occur if Rh negative
mother gives birth to Rh positive baby
 Mother may develop anti-Rh antibodies
 Future pregnancies may result in these
antibodies causing agglutination of
babies blood
 However injections have been
developed that correct this problem

Blood Clotting
Platelets broken open by damaged
blood vessels
 Platelets release chemicals that convert
prothrombrin into thrombrin
 Thrombrin causes fibrinogen molecules
to join together to form strands called
Fibrin
 Many strands of Fibrin form amesh or
clot that stops the bleeding

Blood Clotting
Blood Problems
Anemia - occurs when there is a
shortage of hemoglobin ib blood
 Leukemia - Cancer of the white blood
cells
 A.I.D.S - the H.I.V. virus attacks and
destroys an important type of WBC
 Sickle Cell Disease - abnormal
hemoglobin causes RBC s to have
irregular shape
