blood and its components

This is a series of lectures on microbiology useful for undergraduate medical and paramedical students

1. Blood Blood
What is it and why is it important?What is it and why is it important?
Dr. Ashish V. Jawarkar M.D.Dr. Ashish V. Jawarkar M.D.
Consultant PathologistConsultant Pathologist
Parul Sevashram HospitalParul Sevashram Hospital

2. BloodBlood
The average adult has about five The average adult has about five
liters of blood living inside of their liters of blood living inside of their
body, coursing through their vessels, body, coursing through their vessels,
delivering essential elements, and delivering essential elements, and
removing harmful wastes.removing harmful wastes.
Without blood, the human body Without blood, the human body
would stop workingwould stop working

3. BloodBlood functions functions
Blood is the Blood is the fluid of growthfluid of growth, ,
transporting nourishment from transporting nourishment from
digestion and hormones from glands digestion and hormones from glands
throughout the body. throughout the body.
Blood is the Blood is the fluid of healthfluid of health, ,
transporting disease fighting transporting disease fighting
substances to the tissue and waste substances to the tissue and waste
to the kidneys.to the kidneys.

4. Bloods Major FunctionBloods Major Function
Blood is the Blood is the fluid of lifefluid of life, transporting , transporting
oxygen from the lungs to body tissue oxygen from the lungs to body tissue
and carbon dioxide from body tissue and carbon dioxide from body tissue
to the lungs.to the lungs.

5. Blood PercentagesBlood Percentages
55 % plasma55 % plasma
–PlasmaPlasma is the straw-colored liquid in is the straw-colored liquid in
which the blood cells are suspended. which the blood cells are suspended.
45 % cells45 % cells
–Red blood cells (Erythrocytes)Red blood cells (Erythrocytes)
–White blood cells (leukocytes)White blood cells (leukocytes)
–Platelets (thrombocytes)Platelets (thrombocytes)

6. Blood Components Blood Components

7. PlasmaPlasma
Plasma is the relatively clear Plasma is the relatively clear liquid water , liquid water ,
sugar, fat, protein and salt solutionsugar, fat, protein and salt solution which which
carries the red cells, white cells, platelets, and carries the red cells, white cells, platelets, and
some other chemicals. some other chemicals.
Normally, 55% of our blood's volume is made Normally, 55% of our blood's volume is made
up of plasma. About 95% of it consists of up of plasma. About 95% of it consists of
water. water.
As the heart pumps blood to cells throughout As the heart pumps blood to cells throughout
the body, plasma brings nourishment to them the body, plasma brings nourishment to them
and removes the waste products of metabolismand removes the waste products of metabolism

8. Red blood cells (erythrocytes)Red blood cells (erythrocytes)
Red blood cells are biconcave discsRed blood cells are biconcave discs
erythrocytes erythrocytes

10. Red Blood CellsRed Blood Cells
Red cells, or Red cells, or erythrocyteserythrocytes , cells without , cells without
nuclei. nuclei.
Red cells normally make up 40-50% of the Red cells normally make up 40-50% of the
total blood volume. total blood volume.
They transport oxygen from the lungs to all of They transport oxygen from the lungs to all of
the living tissues of the body and carry away the living tissues of the body and carry away
carbon dioxide. carbon dioxide.
The red cells are produced continuously in The red cells are produced continuously in
our bone marrow from stem cells at a rate of our bone marrow from stem cells at a rate of
about 2-3 million cells per second. about 2-3 million cells per second.

11. Cont.Cont.
HemoglobinHemoglobin is the gas transporting is the gas transporting
protein molecule that makes up 95% of protein molecule that makes up 95% of
a red cell. a red cell.
The red color of blood is primarily due to The red color of blood is primarily due to
oxygenated red cells. oxygenated red cells.

12. White Blood Cell (White Blood Cell (leukocytes)leukocytes)

15. White Blood CellsWhite Blood Cells
White cells, or White cells, or leukocytesleukocytes , exist in variable , exist in variable
numbers and types but make up a very small numbers and types but make up a very small
part of blood's volume--normally only about 1% part of blood's volume--normally only about 1%
in healthy people. in healthy people.
Most are produced in our bone marrow from Most are produced in our bone marrow from
the same kind of stem cells that produce red the same kind of stem cells that produce red
blood cells.blood cells.

16. Cont.Cont.
Some white cells (called lymphocytes ) Some white cells (called lymphocytes )
are the third line of defence, part of are the third line of defence, part of
acquired immunity. acquired immunity.
–They seek out, identify, and bind to They seek out, identify, and bind to
alien protein on bacteria, viruses, and alien protein on bacteria, viruses, and
fungi so that they can be removed. fungi so that they can be removed.
– Other white cells (called neutrophils, Other white cells (called neutrophils,
nk cells and macrophages ) form a nk cells and macrophages ) form a
part of innate immunity and are the part of innate immunity and are the
first line of defence.first line of defence.

17. Leukocytes(wbc’s) Total Leukocytes(wbc’s) Total
Neutrophils 60-70% Neutrophils 60-70% (N)EVER(N)EVER
Lymphocytes 20-25% Lymphocytes 20-25% (L)ET(L)ET
Monocytes 3-8%Monocytes 3-8% (M)ONKEYS(M)ONKEYS
Eosinophils 1-3%Eosinophils 1-3% (E)AT(E)AT
Basophils ½ to 1%Basophils ½ to 1% (B)ANANAS(B)ANANAS

18. Granulocytes Granulocytes
Granulocytes are white blood cells whose Granulocytes are white blood cells whose
cytoplasm contains tiny granules. The cells are cytoplasm contains tiny granules. The cells are
named according to the staining characteristics named according to the staining characteristics
of the granules.of the granules.

19. NeutrophilsNeutrophils
NeutrophilsNeutrophils - the granules are purple - the granules are purple
coloredcolored
–Neutrophils are phagocytic cells; they Neutrophils are phagocytic cells; they
engulf foreign materialengulf foreign material
–Part of second line of defencePart of second line of defence

21. EosinophilEosinophil
Have dense red granulesHave dense red granules
Play a part in allergic responsePlay a part in allergic response
Count is increased in allergiesCount is increased in allergies

23. BasophilsBasophils
Basophils have dark blue-staining Basophils have dark blue-staining
granules. granules.
They are the least numerous blood cells.They are the least numerous blood cells.
Numbers are increased in leukemiasNumbers are increased in leukemias

25. Agranulocytes Agranulocytes
Agranulocytes are white blood cells Agranulocytes are white blood cells
that have no distinct granules in that have no distinct granules in
their cytoplasm.their cytoplasm.
LymphocytesLymphocytes have large single have large single
nuclei that occupy most of the cells. nuclei that occupy most of the cells.
They are an important part of the body's They are an important part of the body's
immune system.immune system.

26. LymphocyteLymphocyte

27. Types of lymphocytesTypes of lymphocytes
T-cellsT-cells
B- cellsB- cells

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Third line of defence - Lymphocytes
Lymphocytes are a type of white blood cell found in the
blood or lymph nodes and made by bone marrow. There are
several types of lymphocyte, including:
T-lymphocytes – recognise antigens
on pathogens and either attack them
directly or co-ordinate the activity of
other cells of the immune system.
B-lymphocytes – recognise
antigens and produce special
chemicals called antibodies.

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B lymphocytes
Antibodies are special
Y-shaped proteins
produced by
B-lymphocytes in
response to antigens.
Antibodies work by binding to antigens on pathogens,
‘labelling’ them and causing them to clump together.
The pathogen can then be destroyed by:
the antibodies themselves.
phagocytosis by macrophages
T-lymphocytes

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Antibodies
Each different type of antigen causes a different type of
antibody to be produced.
An antibody can only bind to the antigen that caused it to be
produced.

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Delayed response
The B-lymphocyte that produces the correct antibody for the
antigen begins dividing to produce many more antibody-
producing cells.
It takes a few days to produce enough
antibodies to destroy the pathogen. This
means there is delay between infection
and the person beginning to feel better.
Once a pathogen has been destroyed, a few memory cells
remain. These recognize the pathogen if it re-infects, and
make the immune response much quicker and more effective.
This is called active immunity.

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33. ContCont
Monocytes Monocytes are the largest of the are the largest of the
white blood cells. In tissues k/a white blood cells. In tissues k/a
macrophagesmacrophages
They have large pleomorphic They have large pleomorphic
(variously shaped) single nuclei and (variously shaped) single nuclei and
function mainly as phagocytic function mainly as phagocytic
(engulfing) cells . (engulfing) cells .
They are important in the long-term They are important in the long-term
cleanup of debris in an area of cleanup of debris in an area of
injury.injury.

34. Cont.Cont.
Monocyte (left)

47. Watch this and many more Watch this and many more
animations @ animations @
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view0/chapter2/animation__phagocyview0/chapter2/animation__phagocy
tosis.htmltosis.html

48. Platelets (Platelets (thrombocytes)thrombocytes)
Platelets

49. PlateletsPlatelets
Platelets , or Platelets , or thrombocytesthrombocytes , are cell , are cell
fragments without nuclei that work fragments without nuclei that work
with blood clotting chemicals at the with blood clotting chemicals at the
site of wounds. site of wounds.
–They do this by adhering to the walls of blood They do this by adhering to the walls of blood
vessels, thereby plugging the rupture in the vessels, thereby plugging the rupture in the
vascular wall. They also can release coagulating vascular wall. They also can release coagulating
chemicals which cause clots to form in the blood chemicals which cause clots to form in the blood
that can plug up narrowed blood vessels. that can plug up narrowed blood vessels.

52. Blood loss Blood loss
When the human body loses a little When the human body loses a little
bit of blood through a minor wound, bit of blood through a minor wound,
the platelets cause the blood to clot the platelets cause the blood to clot
so that the bleeding stops. so that the bleeding stops.
Because new blood is always being Because new blood is always being
made inside of your bones, the body made inside of your bones, the body
can replace the lost blood.can replace the lost blood.

53. Blood replacement Blood replacement
When the human body loses a lot of When the human body loses a lot of
blood through a major wound, that blood through a major wound, that
blood has to be replaced through a blood has to be replaced through a
blood transfusion from other people.blood transfusion from other people.