About Blood Cells
Blood is a special liquid connective tissue that preserves
human life, through which various blood vessels carry nutrients, electrolytes,
hormones, vitamins, antibodies, Oxygen, immune cells, etc. to all cells of the
body and which also removes carbon dioxide and other waste products.
A human body contains about 5-6 liters of blood, which is
10% of the total body weight.
Blood is slightly alkaline.
pH values = 7.35-7.45 (water pH = 7.0, less than it is called acid & more than
it is called basic)
Temperatures = 36° - 38° C.
Components of
bloods:
Blood cell separate into 2 layers.
Plasma:
Plasma
is the yellow liquid part of blood. Its water content is 92% and dissolved
solids content is 8%. Plasma consists of various organic and inorganic
components of solid matter.
Inorganic Components: Sodium Chloride (NaCl), Sodium
bicarbonate (NaHCO3), Calcium (Ca), Potassium (K), Magnesium (Ma),
Phosphorus (P), Iron (Fe), Iodine (I) etc.
Organic Components: Plasma protein, Nitrogenous excretory products and
Glucose, Fat, Cholesterol, Hormone, Vitamins, Dyes etc.
Work of Plasma:
1.
Plasma maintains blood fluidity and
transports floating blood cells and other dissolved substances.
2.
After digestion, food is dissolved in
plasma and carried to different tissues and organs of the body.
3.
The waste products that are removed
from the tissues are taken to the kidneys for excretion.
4.
The most of Carbon dioxide (Co2)
in tissues is dissolved in plasma as bicarbonate.
5.
A small amount of oxygen is carried in
it.
6.
Oxygen (O2) first dissolves
in the plasma before it enters the red blood cells.
7.
Hormones, enzymes, lipids are carried
to various organs through plasma.
8.
Plasma maintains the acid-base balance
of the blood.
9. Transports substances necessary for blood clotting.
Blood Corpuscles:
Different types of cells
floating in plasma are called blood cells. Blood cells are mainly of three
types:
1.
Erythrocytes,
2.
Leukocytes,
3.
Thrombocytes.
Erythrocytes: In humans, mature red
blood cells are round, biconcave, disc-like without a nucleus and red in color.
Its edges are smooth and thicker than the middle. The mature granule is highly
flexible and elastic. Each red blood cell has an average thickness of 7.3µm and
an average thickness of 2.2 µm.
The number of blood cells per cubic millimeter of
blood in the human body of different ages is: 80-90 million in the fetal body;
60-70 lakhs in the child's body; 50 lakhs in adult males; 45 lakhs in adult females.
Anemia occurs when the number of red cells per cubic
millimeter of blood is less than 500,000 by 25%. But if this number is more
than 65 lakh for any reason, it is called polycythemia.
Erythrocytes arise from large embryonic cells called
stem cells or hemocytoblasts located in the bone marrow. The life span of this
cell is short as it does not have a nucleus. Besides granules are destroyed in
the liver and spleen.
Work of Erythrocytes:
1. Hemoglobin in red blood cells
transports most of the Oxygen (O2), and a small amount of Carbon
dioxide (CO2), from the lungs to the body cells.
2. Hemoglobin and other intracellular
substances act as buffers to maintain the acid-base balance of the blood.
3. These cells produce bilirubin and biliverdin in the blood.
Leucocyte: In the human body, mature white blood
cells are large cells without hemoglobin, irregular and nucleated. They are
called white blood cells because they do not contain any pigment.
These blood cells are called mobile
defense units of the body because they destroy microbes by the process of
phagocytosis. Human white blood cells are shapeless. Size varies as needed.
Nucleus is positioned at the extreme end under the pressure of cytoplasm. They
are larger than red blood cells, with an average diameter of 7.5–20 µm, varying
in shape. Human body has 5-8 thousand white blood cells per cubic millimeter of
blood. Furthermore, the number increases in children and
sick human bodies. The erythrocyte to leukocyte ratio is 700 : 1.
Shape and structure of white blood
cells can be divided into two main parts, namely-
a. Agranulocytes
b. Granulocytes
There are also 2 types of agranulocytes exist. Like-
i)
Lymphocyte
ii)
Monocyte
Lymphocyte:-Lifetime 100-120
days. Produces antibodies and destroys some microorganisms.
Monocyte:-Lifetime 10-12
days. They fight disease by eating microbes through phagocytosis.
There are also 3 types of granulocytes exist. Like-
i)
Neutrophil
ii)
Eosinophil
iii)
Basophil
Neutrophil:- A type of white blood cell that is an important part of
the immune system and helps the body fight infection. When microorganisms, such
as bacteria or viruses, enter the body, neutrophils are among the first immune
cells to respond.
Eosinophil:-
The
cytoplasm of this cell is granular, acidic. Their nucleus is usually 2
fragmented. They increase the immunity of the body.
Basophil:- The cytoplasm of these cells is granular and relatively slightly alkaline. Basophils increase the immune system by releasing histamine and prevent clotting between blood and blood vessels by releasing Heparin.
Work of Leucocyte:
1.
Monocytes and neutrophils ingest and destroy pathogens in
the process of phagocytosis.
2.
Lymphocytes fight disease by producing antibodies.
3.
Basophils produce heparin, which prevents blood clots
inside blood vessels.
4.
Granular leukocytes increase the body's immune system by
producing histamine.
5.
Neutrophils destroys the poisonous seed germs.
6.
Thrombocytes or platelets: Clostridium difficiles are
small, colorless, non-nucleated, oval disc-like components of the blood, whose
function is to help blood clot and stop bleeding. In English it is known as
Platelet. It contains protein and a large amount of phospholipid called Cephalin.
According to some scientists, they originate from the large megakaryocytes of
the red bone marrow. According to others, thrombocytes arise from white blood
cells.
The average lifespan of platelets is about 5-10 days.
At the end of life, platelets are destroyed in the spleen and other Reticulo-endothelial
cells.
Work of Thrombocytes or platelets:
1.
Causes blood coagulation at the wound site, and stops
bleeding by forming a hemostatic plug.
2.
Reconstructs the damaged endothelial lining of blood
vessels.
3.
Carbon particles, in the process of phagocytosis and eat
the virus.
4. Stores histamine and 5HT.
Determination of Human Blood Group
Theory:
Blood is often given as a life-saving approach to a patient's body. In this case, the blood of the donor must match the blood of the recipient. Antigens are present in human red blood cells and antibodies are present in plasma or serum. Human blood groups are divided into four groups based on the presence and absence of antigens and antibodies. They are A, B, AB and O.
In 1901, Karl Landsteiner was the first to discover this blood group in humans.
The chart below shows to whom a group can give blood or receive blood from a group:
Blood Group
Antigen
Antibody
Can donate blood To
Can receive blood From
A
A
b
A & AB
A & O
B
B
a
B & AB
B & O
AB
A & B
×
AB
A, B, AB, O
O
×
a & b
A, B, AB, O
O
Required Components:
i) A compound microscope.
ii) Grooved slide 1.
iii) Glass marking pencil.
iv) Serum – Anti A, Anti B, Anti D.
v) Lancet or sterile needle
vi) Cotton
vii) Ethyl alcohol (C2H5OH)
Procedures:
1 clean tri-grooved slide or 3 normal clean slides should be taken. 3 grooves of the grooved slide should be marked A, B and D respectively with a glass marking pencil. Then the person whose blood type is to be determined, the tip of his finger should be punctured with a sterile needle to draw blood. 3 drops of blood should be taken from the same person at the places marked A, B and D on the slide. Then add one drop of Anti-A serum to the place marked A, one drop of Anti-B serum to the place marked B and Anti-D serum to the place marked D. Serum should be mixed with blood by three shakers. After 2-5 minutes later the blood should be observed with the help of a Microscope.
At the place marked A, the blood group is 'A' if the red blood cells (erythrocytes) are clustered. Same as, at the place marked B, the blood group is ‘B’ if the red blood cells (erythrocytes) are clustered. Moreover, if the red blood cells (erythrocytes) of both A and B are agglutination together, the blood group will be 'AB'. In the areas marked A and B, the color group will be ‘O’ if the red blood cells (erythrocytes) are not agglutination at all. Blood group marked D, red blood cells (erythrocytes) group will be 'Rh +' agglutination and blood group marked D, red blood cells (erythrocytes) not agglutination, blood group will be 'Rh -'.
|
Blood Group |
Red Blood Cells
(erythrocytes) antigens (Agglutinogen) |
Blood Serum antibody (Agglutinin) |
Reaction |
|
|
Anti – A Serum |
Anti – B Serum |
|||
O Universal Donor |
NO |
a/ α and b/ β |
Not Agglutination |
Not Agglutination |
|
A |
A |
b/ β |
Agglutination |
Not Agglutination |
|
B |
B |
a/ α |
Not Agglutination |
Agglutination |
AB Universal Donor |
A & B |
NO |
Agglutination |
Agglutination |
|
Rh Factor |
Antigen “D” |
Reaction with Anti-D Serum |
Can Receive From |
Can Receive From |
|
Rh+ |
Present |
Agglutination |
Rh+ and Rh- |
Rh |
|
Rh- |
Absent |
Not Agglutination |
Rh- |
Rh+ and Rh- |
Rh Factor: Refers to the presence or absence of the D antigen on red blood cells.
Reaction with Anti-D Serum: Agglutination indicates Rh+ (positive), and no agglutination indicates Rh- (negative).
Compatibility:
i) Rh+ can receive from both Rh+ and Rh-.
ii) Rh- can only receive from Rh-.
iii) Rh- can donate to both Rh+ and Rh-.
Caution:
1. If the needle is used while drawing blood, burn it with a flame to sterilize it.
2. Check if the serum is active.
3. Slides must be clean.
4. After mixing the serum, the condition of the blood should be observed under a microscope.
5. After applying the serum, mix well by stir rod and leave for 2 to 5 minute
“SAVE FOREST, SAVE SPECIES AND KNOW THEM CLOSELY”