Haemopoetic system Introduction

1. HAEMOPOIETIC
SYSTEM
INTRODUCTION

2. HAEMOPOIETIC SYSTEM
• Haematopoiesis is the production of all the cellular components of blood and blood
plasma.
• It occurs within the hematopoietic system, which includes organs and tissues such as
the bone marrow, liver, and spleen.
• Simply, haematopoiesis is the process through which the body manufactures blood
cells.
• It begins early in the development of an embryo, well before birth, and continues for the
life of an individual.
• Haematopoiesis begins during the first weeks of embryonic development.
• All blood cells and plasma develop from a stem cell that can develop into any other cell.
• Current research endorses a theory of hematopoiesis called the monophyletic theory.
This theory says that one type of stem cell produces all types of blood cells.

3. CELLULAR COMPONENTS
• The blood is made up of more than 10 different cell types. Each of these cell types falls into one of
three broad categories:
• 1. Red blood cells (erythrocytes): These transport oxygen and haemoglobin throughout the body.
• 2. White blood cells (leukocytes): These support the immune system. There are several different
types of white blood cells:
• Lymphocytes: Including T cells and B cells, which help fight some viruses and tumours.
• Neutrophils: These help fight bacterial and fungal infections.
• Eosinophils: These play a role in the inflammatory response and help fight some parasites.
• Basophils: These releases the histamines necessary for the inflammatory response.
• Macrophages: These engulf and digest debris, including bacteria.
• 3. Platelets (thrombocytes): These help the blood to clot. They are formed from a bone marrow cell
known as the megakaryocyte.

4. DIFFERENCE BETWEEN BLOOD,
PLASMA AND SERUM
• Blood is the body’s fluid connective tissue that constitutes 55%
plasma and 45% blood cells.
• Plasma is the liquid portion of blood.
• It is composed of serum and clotting factors.
• About 55% of our blood is plasma, and the remaining 45% are
red blood cells, white blood cells and platelets that are
suspended in the plasma.
• Plasma is about 92% water.
• The serum is the liquid or undiluted part of the blood, which
lacks clotting factors. Hence, it is formed after blood
coagulation.

5. FUNCTIONS OF DIFFERENT LEUKOCYTES

7. OCCURRENCE OF HEMATOPOIESIS
• Haematopoiesis in the embryo (Primitive Haematopoiesis)
• The embryo produces only red blood cells that can provide oxygen to developing
organs.
• At this stage in development, the yolk sac, which nourishes the embryo until the
placenta is fully developed, controls haematopoiesis.
• As the embryo develops, the haematopoiesis process moves to the liver, the spleen,
and bone marrow and produces other blood cells.
• In adults, haematopoiesis of red blood cells and platelets occurs primarily in the bone
marrow.
• In infants and children, it may also continue in the spleen and liver.
• The lymph system, particularly the spleen, lymph nodes, and thymus, produces a type
of white blood cell called lymphocytes.
• Tissue in the liver, spleen, lymph nodes and other organs produces another type of
white blood cell called monocytes.

8. BLOOD DISORDERS AFFECTING RED BLOOD CELLS
Anaemia
Iron-deficiency
anaemia
Anaemia of chronic
disease
Pernicious anemia
(B12 deficiency)
Aplastic anemia
• Low iron intake and
loss of blood due to
menstruation are the
most common causes
of iron-deficiency
anaemia.
• It may also be caused
by blood loss from
the GI tract because
of ulcers or cancer.
• Treatment includes
iron pills, or rarely,
blood transfusion.
• People with
chronic kidney disea
se tend to develop
anaemia.
• Injections of a
synthetic hormone,
epoetin alfa
(Epogen or Procrit), to
stimulate the
production of blood
cells or blood
transfusions may be
necessary for some
people with this form
of anaemia.
• A condition that prevents
the body from
absorbing enough B12
in the diet.
• This can be caused by a
weakened stomach lining
or an autoimmune
condition.
• Besides anaemia, nerve
damage (neuropathy)
can eventually result.
• High doses of B12
prevent long-term
problems.
• The bone marrow
does not produce
enough blood cells,
including red blood
cells.
• This can be caused by
a host of conditions,
including hepatitis,
Epstein-Barr, or HIV --
to the side effect of a
drug, chemotherapy,
medications, to
pregnancy.
• Medications, blood
transfusions, and even
a bone marrow
transplant may be
required to treat
aplastic anaemia.

9. CONTD….
Anemia Polycythaemia vera
Autoimmune
haemolytic anaemia
Thalassemia Sickle cell anaemia
• An overactive immune
system destroys the
body's own red
blood cells, causing
anaemia.
• Medicines that
suppress the immune
system, such
as prednisone, may
be required to stop
the process.
• This is a genetic
form of anaemia that
mainly affects people
of Mediterranean
heritage.
• Most people have no
symptoms and require
no treatment.
• Others may need
regular blood
transfusions to
relieve anemia
symptoms.
• A genetic condition
that affects most
people whose families
have come from
Africa, South or
Central America, the
Caribbean islands,
India, Saudi Arabia,
and Mediterranean
countries.
• In sickle cell anaemia,
the red blood cells
are sticky and stiff.
• They can block blood
flow. Severe pain and
organ damage can
occur.
• The body produces
too many blood cells
from an unknown
cause.
• The excess red blood
cells usually create no
problems but may
cause blood clots in
some people.

10. BLOOD DISORDERS AFFECTING WHITE BLOOD CELLS
Lymphoma Leukaemia Multiple myeloma Myelodysplastic
syndrome
• A form of
blood cancer that
develops in the
lymph system.
• In lymphoma, a white
blood cell becomes
malignant, multiplying
and spreading
abnormally.
• Hodgkin's
lymphoma and non-
Hodgkin's lymphoma
are the two major
groups of lymphoma.
• Treatment
with chemotherapy and
/or radiation can often
extend life with
lymphoma, and
sometimes cure it.
• A form of
blood cancer in
which a white blood
cell becomes
malignant and
multiplies inside
bone marrow.
• Leukaemia may be
acute (rapid and
severe) or chronic
(slowly progressing).
• Chemotherapy
and/or stem
cell transplantation
(bone marrow
transplant) can be
used to treat
leukaemia and may
result in a cure.
• A blood cancer in
which a white blood
cell called a plasma
cell becomes
malignant.
• The plasma cells
multiply and release
damaging substances
that eventually cause
organ damage.
• Multiple myeloma has
no cure, but stem
cell transplant and/or
chemotherapy can
allow many people to
live for years with the
condition.
• A family of blood
cancers that affect
the bone marrow.
• The myelodysplastic
syndrome often
progresses very slowly
but may suddenly
transform into severe
leukaemia.
• Treatments may
include blood
transfusions,
chemotherapy and
stem cell transplant.

11. BLOOD DISORDERS AFFECTING PLATELETS
Thrombocytopenia Idiopathic
thrombocytopenic
purpura
Heparin-induced
thrombocytopenia
Thrombotic
thrombocytopenic
purpura
Essential
thrombocytosis
(primary
thrombocythemia)
• A low number of
platelets in the
blood.
• Numerous
conditions cause
thrombocytopeni
a, but most do
not result in
abnormal
bleeding.
• A condition
causing a
persistently low
number of
platelets in the
blood, due to an
unknown cause.
• Usually, there are
no symptoms, yet
abnormal
bruising, small
red spots on the
skin (petechiae),
or abnormal
bleeding can
result.
• A low platelet
count caused
by a reaction
against heparin,
a blood
thinner given to
many
hospitalized
people to
prevent blood
clots.
• A rare blood
disorder causing
small blood
clots to form in
blood vessels
throughout the
body.
• Platelets are
used up in the
process, causing
a low platelet
count.
• The body
produces too
many platelets,
due to an
unknown cause.
• The platelets do
not work
properly,
resulting in
excessive
clotting, bleeding,
or both.

12. BLOOD DISORDERS AFFECTING BLOOD PLASMA
Hemophilia von Willebrand
disease
Hypercoagulable
state
Deep venous
thrombosis
Disseminated
intravascular
coagulation (DIC)
• A genetic
deficiency of
certain proteins
that help blood to
clot.
• There are multiple
forms of
haemophilia,
ranging in severity
from mild to life-
threatening.
• von Willebrand
factor is a protein
in blood that helps
blood to clot.
• In this, the body
either produces
too little of the
protein, or
produces faulty
protein.
• The condition is
inherited, but most
people have no
symptoms.
• Some people with
this disease will
have excessive
bleeding after an
injury or during
surgery.
• A tendency for the
blood to clot too
easily.
• Most affected
people have only a
mild excess
tendency to clot,
and may never be
diagnosed.
• Some people
develop repeated
episodes of blood
clotting throughout
life, requiring them
to take a daily
blood thinning
medicine.
• A blood clot in a
deep vein, usually
in the leg.
• A deep venous
thrombosis can
dislodge and travel
through
the heart to
the lungs, causing
a pulmonary
embolism.
• A condition that
causes tiny blood
clots and areas of
bleeding
throughout the
body
simultaneously.
• Severe infections,
surgery, or
complications of
pregnancy are
conditions that can
lead to DIC.

14. PROPERTIES OF BLOOD
• The average adult has a blood volume of approximately 5 L, which comprises about 7–9%
of the body’s weight.
• Men have 5–6 L and women 4–5 L.
• Blood is thicker and denser due to red blood cells and plasma proteins such as albumin
and fibrinogen.
• Plasma proteins, including albumin, fibrinogen, prothrombin, and gamma globulins,
constitute about 7-8% of the blood plasma in the body.
• These proteins help maintain water balance, and they affect osmotic pressure, increase
blood viscosity and help maintain blood pressure.
• All the plasma proteins are synthesized in the liver except the gamma globulins (cells of
lymphoid system).
• The normal osmolality of extracellular fluid is 285–295 mosmol/kg.
• If the osmolality is approximately 600 mosmol (Hypertonic)→ RBCs could crenate (shrivel
up) and die.
• If the osmolality is below 150 mosmol (Hypotonic)→ Haemolysis (rupture) of the RBCs
could occur.

15. CONTD….
• The viscosity of the blood ranges from 3.5 to 5.5 compared with 1.000 for
water.
• The specific gravity (density) of blood is 1.045–1.065 compared with 1.000
for water.
• The pH of blood ranges from 7.35 to 7.45.
• Blood plasma is a pale yellow-colored fluid.
• total volume in an adult is approximately 2.5–3 L.
• Blood plasma is approximately 91% water and 10% solutes, most of which
are proteins.
• Plasma constitutes approximately 55% of blood volume.
• Water constitutes approximately 91% of the plasma and is available to cells,
tissues, and extracellular fluid of the body to maintain homeostasis.

16. COMPOSITIONS OF PLASMA AND THEIR FUNCTIONS

17. FUNCTIONS OF BLOOD
1. Transportation: The blood is the means whereby all nourishment and respiratory gases
are transported into and out of the cells.
2. Maintaining body temperature: Blood helps to maintain the body temperature by
distributing the heat produced by the chemical activity of the cells evenly throughout the
body.
3. Maintaining the acid-base balance: Blood pH is maintained by the excretion or
reabsorption of hydrogen ions and bicarbonate ions.
4. Regulation of fluid balance: When the blood reaches the kidneys, excess fluid is
excreted or reabsorbed to maintain fluid balance.
5. Removal of waste products: The blood removes all waste products from the tissues and
cells. These waste products are transported to the appropriate organs for excretion –
lungs, kidneys, intestine, and skin.
6. Blood clotting: By the mechanism of clotting, loss of blood cells and body fluids is
prevented.
7. Defence action: The blood aids in the defence of the body against the invasion of
microorganisms and their toxins due to the phagocyte action of neutrophils and
monocytes; and the presence of antibodies and antitoxins.