Blood consists of plasma and formed elements. Plasma contains proteins and electrolytes while formed elements are blood cells including erythrocytes, leukocytes, and platelets. Erythrocytes are biconcave discs that contain hemoglobin and transport oxygen. Leukocytes include granulocytes like neutrophils, eosinophils and basophils and agranulocytes like lymphocytes and monocytes that protect against infection. Platelets are cell fragments involved in blood clotting. Hematopoiesis occurs in the bone marrow where stem cells differentiate into various blood cell types through the influence of growth factors like erythropoietin and cytokines. Blood groups are determined by

2. By: Dr. Surekha Aditya
Bakle

3. Constituents of the blood
Blood is about 8% of the total body weight (5L). It is either arterial blood or
venous blood.
- Blood consists of :
1- Plasma: fluid part of blood contains proteins and electrolytes.
2- Formed elements: blood cells (erythrocytes, white blood cells, platelets).

5. Plasma proteins
Plasma Proteins:
7%-9% of plasma volume.
i- Mainly albumins: account for 60% to 80% of the plasma
proteins (produced by the liver).
ii- Globulins:
iiA- Alpha globulin and Beta globulin: transport lipids- and fatsdissolved vitamins.
iiB- Gamma globulins: antibodies produced by lymphocytes
(immunity).
iii- Fibrinogen: essential for blood clotting (produced by the
liver).

6. Formed elements :
cells and cell
fragments (platelets)
The cells of blood :
• red blood cells
(RBC)
• white blood cells
(WBCs, leukocytes).

7. Formed elements of the blood
1- Red blood cells (erythrocytes)
• Most abundant cells of the blood.
• Do not have a nucleus
• Biconcave discs, 7 m diameter and
2.2 m thick.
•
•
Haemoglobin carries oxygen
around the body.
•
Hemoglobin
Contain the protein haemoglobin.
At the centre of the haemoglobin
molecule is an iron atom (heme).

8. Note the 4 protein chains
that make up 1 molecule of
Hb.
Note that, in muscle, myoglob
(Mb) binds oxygen. Mb consist
of only 1 protein chain.

9. 2- Platelets
• Called also Thrombocytes.
• The smallest of the formed elements.
• They play an important role in blood clotting.

10. 3- White blood cells WBC (Leukocytes)
• Protective cells of the body. They contain nuclei, move in amoeboid fashion
and they can pass the capillary wall (diapedesis or extravasation).
• They are granular or agranular (non granular).
• Neutrophils are the most abundant type of the granular cells.
Granular
Agranular

11. 

Protect against infection: phagocytize bacteria; produce proteins that
destroy foreign particles
Diapedesis: leukocytes can squeeze between cells and leave the circulation
Fig. 14.14

12. Infectio
n

14. •60-70%
of total
leucocytes
•9-12 µm in diameter
•Multilobe nucleus
•Female : drum
stick/Barr Body
• Granules :
•Small
spesific granules
•Azurophilic granules (Lysosomes)
•Tertiary granules (gelatine and
cathepsins)
•Function
:
• Phagocytes

15. 4% of total leucocyte
10 - 14 µm in diameter
Bilobed nucleus
Many large spesific
granules stained by eosin
Function :
• Eliminate antibodyantigen complexes
• Destroy parasitic
worms

16. <1% of total leucocyte
8-10 µm in diameter
S-shape nucleus (irregular
lobes)
Large spesific granules
obscured the nucleus
Granules (dark blue) contain
heparin & histamin
Surface receptor (Ig E
receptors)
Function :
As initiator of inflamatory
process

17. 20%-25% of total
leucocyte
8-10 µm in diameter
Round nucleus with
slight indented, occupies
most of the cell
Contain few azurophilic
granules

18. Largest circulating
blood cells
3-8% ot total leucocyte
Large, acentric,
kidney- shape nucleus
numerous azurophlic
granules
Migrate to the
connective tissue 
MACROPHAGES
(phagocytose antigens
and as APC)

19. 250.000-400.000
platelets/mm3
2 to 4 µm in diameter
Display peripheral clear
region (hyalomere ) and
central darker region
(granulomere)
receptor molecules
(glycocalyx) on
plasmalemma
Function : Blood clott

20.  Mature
blood cells have a relatively short life
span
 Must be continusly replaced by stem cells
 Stem cells produce in HEMATOPOIETIC ORGAN

21. Formation of blood cells
1- Hematopoiesis
Blood cells are formed by a process of hematopoiesis.
During embryogenesis the blood cells are formed from stem cells in the liver.
Soon after birth the stem cells migrate to the bone marrow.
Erythropoiesis is the formation of erythrocytes.
Leukopoiesis is the formation of leukocytes.
Bone marrow

22.  Subdivide

Mesoblastic :





Begins at 6 weeks until end of gestation
Nucleated erythrocyte
Appear of leucocyte (8th week)
Splenic


begin after 2 weeks after conception at yolk sac
Mesenchymal cells aggregate into blood islands
Hepatic


into four phases :
Begin at second trimester until end of gestation
Myeloid


Begin at the end of second trimester
Hemopoiesis at bone marrow

23.  Hemopoiesis
almost exclusively in BONE
MARROW
 Stem cells undergo


multiple cells divisions
and differentiation
 Replace
the cells that leave the blood
stream, die or destroy

25. A gelatinous, vascular
connective tissue located in
medulary cavity of long bones
Responsible for hemopoiesis
Structure :
Vascular compartment
Extensive network of
sinusoids , arteries and
veins form the
Hemopoietic compartment
Islands of hematopoietic
cells
Hemopoietic cells in various
stage of maturation

26.  Regulated
the hemopoiesis
 Produce by spesific cells
 Acts on specific stem cells, progenitor cells,
and precursor cells
 The route to deliver growth factor :



Via blood stream
Secrete near the hemopoietic cells
Direct cell-cell contact
 Induced
rapid mitosis or and differentiation
 Most ot them are glycoproteins

29.  Formation
of red blood cells
 Generates 2.5 x 10 11 erythrocytes /day
 By two types of unipotential progenitor cell


BFU-E
CFU-E
 Regulate
by : erythropoietin

30. A- Erythropoiesis
Erythropoieis = the process of
formation of erythrocytes (RBCs).
This process occurs in the bone
marrow (myeloid tissue).
Bone marrow/myeloid tissue is the
red tissue inside bones.
This process takes 3 days. 2 days in
bone marrow and circulate in the blood
in the 3rd day.
Life span of a blood cell is 120 days after
which it is removed by the phagocytic
cells of spleen, liver and bone marrow.

31. .

34. Biconcave-shape disk
Without nuclei and
organelles
Have soluble enzymes
Filled with Hemoglobin
(Hb)
Average life span of
erythrocyte : 120 days

35. B- Leukopoiesis
Leukopoieis = the process of formation
of leukocytes (WBCs).
This process occurs in lymphoid tissue
(lymph nodes, tonsils, spleen and
thymus.)

36.  Formation
of the granulocytes (neuthrophil,
eosinophil, and basophil



CFU-Eo : eosinophil lineage
CFU-Ba : Basophil lineage
CFU-GM



CFH-G : Neutrophil line
CFU-M : monocyte line
Influence by G-CSF, GM-CSF

41. CFU-GM
CFU-G
CFU-M
PROMONOCYTES
MONOCYTE

43.  CFU-Meg,
gives rise the Megakaryoblast
 Megakaryoblast differentiate 
Megakaryocytes (single lobulated nucleus)
 Megakaryocytes protrude  clusters of
proplatelets  platelets

44. MEGAKARYOCYTE

45.  CFU-Ly
divides form the CFU-LyB and CFU-LyT
 CFU-LyB migrate to “bursa-equivalent
location”, divided  B lymphocytes
 CFU-LyT undergo mitosis migrate to the
Thymus  T lymphocytes

46. LYMPHOBLAST

47. Red blood cells antigens and blood types (ABO system)
There are certain molecules on the
surface of RBCs. These molecules
are called antigens (agglutinogens).
As a part of our body defense
system (immune system) some
WBCs (lymphocytes) secret proteins
called antibodies (agglutinins).
Every antigen type is coupled with
antibodies secreted by the
lymphocytes act against the other
antigens.
Antibodies can bind to antigens
Destroy RBCs

48. Gentotyping
Here the normal genetic roles of inheritance applies:
A blood group has A antigen which is
shown as IA and antibodies for B.
Blood group B has B antigen which is
shown as IB and antibodies for A.
O has no antigen and is shown as ii.
It has antibodies for A and B.
A person with A may hve got gene A from
each parent (IA IA ) or A from One parent
and O gene from the other (IA i).
A person with group B is (IBIB) or (IBi).
A person with O group has got O gene
from each parent (ii).
A person with AB blood group has got
A gene from one parent and B gene from
the other (IAIB).

49. Genotyping of the blood groups
B O
AO
Note that A and B are
dominants and O is always
recessive.
AO
AB
BO
OO

50. Transfusion reactions
Blood from a donor is usually checked by recipient serum.
If the donor is A and the recipient is B then agglutination will occur.
A accepts A and O, but makes clot with B.
B accepts B and O, but clots with A.
AB accepts A, B and O and called universal
recipient.
O can be given to A, B and AB and called
universal donor.
O accepts only from O and clots with A and
B because it has antibodies against them.
-
anti A
anti B
anti D

51. Blood typing Rhesus factor
Another group of antigens found on RBCs surface
is called Rh factor. People who have this antigen on
their RBCs are Rh positive (Rh+). People without Rh
antigen are Rh negative (Rh-).
The Rh factor is very important when Rh- mother gives birth to Rh+ babies.
Rh- Mother
RBC
RBC
Rh- Mother
Delivery
Rh+ Baby
1st pregnancy
No mixing of blood
Anti-Rh+
Next
pregnancy
RBC
Bloods mixes
RBC
Anti-Rh+
Rh+ Baby
2nd pregnancy
Mother has antibodies
Against baby RBCs

53. 








Expain the composition of the blood!
Explain the structure of formed elements of blood!
How to differentiate the blood cells from a bloodsmear?
Explain the classification and function of leucocyte !
Explain the maturation of lymphocyte!
What blood cell would be in abundance during an
active parasitic infection? Explain your answer!
Eplain the structure and function of platelets!
What blood cell in bone marrow is the earliest
recognizable stage of the red blood cell line?
Describe the structure of erythrocyte if lack of this
nutrient: vitamin B12 and iron during the
erythrocytopoiesis