2. Objectives
Define blood, its general properties and function.
Explain the composition.
Describe the formation of Blood cells
Discuss the structure and functions of blood cells
RBC (Erythrocytes)
WBC (Leukocytes)
Platelets (thrombocytes
Discuss the composition of plasma
Describe the three mechanism that contribute towards
hemostasis
Briefly discuss the ABO blood groups and Rh factor.
3. Blood
It is a connective tissue which consists of
plasma and formed elements (blood cells)
flowing inside the closed vessels.
Physical characteristics of blood
Color Red (varies with O2 content)
Volume 5-6 (males) & 4-5 (Females)
pH 7.35 - 7.45
Viscosity (relative to water) 4.5 – 5.5
% of total body mass 8%
Temperature 380C
Salinity 0.9% Nacl
4. Functions of Blood
1.Transportation
oxygen and carbon dioxide
food molecules (glucose, lipids, amino acids)
ions (e.g., Na+, Ca+2, HCO−3)
wastes (e.g., urea)
hormones
2.Regulation
Body temperature
pH
3.Protection
Clotting
Defense
8. Erythrocytes (RBC)
Physical characteristics of Erythrocyte
Size 7 µm in diameter & 2.2 µm thick
Shape Flattened and biconcave disc
Mean count 4.5-5.5 per mm3 of blood
Morphology Red color, (variable) non-nucleated, each RBC
contains 280 millions Hb molecules, that can carry
over a billion O2 molecule
Site for production Bone marrow
Life span 120 days
Function Carries O2 and nutrients, removes CO2 & wastes
9. Structure of Erythrocyte
(Hemoglobin molecule)
• HEME molecule
Globin Molecule
Hemoglobin molecule
contain 4 protein chains
called globins, each of
which is bound to 1 heme
(iron). Iron is able to
combine with oxygen in
the lungs and deliver it to
body tissues.
is able to combine with
oxygen in the lung and release
oxygen in the tissue.
12. Life Cycle of RBC
• Macrophage in spleen & liver, phagocytize RBC &
split heme & globin
• Globin broken into amino acids to be reused
• Fe removed from heme & attaches to transferrin
• Fe-transferrin → red marrow → Hb synthesis
• Erythropoiesis in red marrow
• Fe removed from heme → non-Fe portion →
biliverdin →bilirubin →bile → GI tract
• Bilirubin →urobilinogen in large intestine →some
urobilinogen →blood → urobilin → yellow pigment in
urine
• Most urobilinogen → feces → as brown pigment
stercobilin
13. Leukocytes (WBC)
They are largest of all blood cells, have nuclei and
do not contain Hb.Forms 1% of blood volume
On the basis of presence of absence of chemical
filled cytoplasmic granules WBCs are classified
into two types:
Granular leukocyte
Agranular leukocyte
Granules
Granulocyte or PMNLS
Agranulcytes
17. Eosinophil (PMNLs)
Life span
%of WBCs: 2-4%
Nucleus 2 large lobes
Granules Stain red
Functions Release enzyme that destroy
parasites
Phagocytosis of antigen antibody
complex, and allergens
18. Agranulocytes
Their nucleus are round or slightly indented and
stains dark
Lymphocyte
T- lymphocyte(T cells)
B- lymphocyte(B cells)
Natural killer cells (NK cells)
Monocyte
19. Lymphocyte
%of WBCs: 20-25 %
Nucleus Nucleus round or slightly indented
Types B-lymphocytes, T-lymphocytes & Natural killer
cells.
Functions B-cells bacteria, T-cells attack microorg and
infected cells, Natural killer cell tumor
B lymphocyte T lymphocyte Natural Killer
cells
20. Monocyte
%of WBCs: 3-8
Nucleus Kidney or horse shoe shape nucleus
Functions Differentiate into macrophages. Phagocytize
pathogens, dead neutrophil and debris of dead
cells
21. Platelets or
Thrombocytes
Size 4 µm in diameter
Shape Disc shape
Mean count 130000-400000 per mm3 of blood
Morphology Non-nucleated fragments of cells
Site for production Bone marrow
Life span 5-9 days
Function Blood clotting
22. Hemostasis/Haemostasis
Heamostasis or cessation of bleeding takes
place through a series of responses, these
include.
• Vasospasm
• Platelet plug formation:
• Coagulation
Follow the sequence to events initiated
when platelets come into contact with an
injured surface
23. Vasospasm
• Vessel wall constricts for a short period
• Platelets (sticky) adhere to the injured wall
• Platelets change their shape
• Platelets (activated) release serotonin that constrict
the vessel
24. Platelet Plug formation
• Passing platelets stick to the site and release
chemicals that attract more platelets.
• More platelets move leading to platelets
aggregation (positive feedback.
• Platelets form a plug or a temporary seal
within six minutes.
25. Coagulation
• Thromboplastin (TP) or tissue factor released
by damaged tissue cells.
• TP activates (through series of chemical
reactions) the inactive clotting factors already
present in the blood.
• Prothrombin activato, first step in final
common pathway.
This final common pathway can be initiated by
two processes usually occurring together…
26. The insoluble fibrin threads
increase in number and forms a
meshwork that trap blood cells and
is much stronger than platelet plug
29. Plasma clotting Factors
Factor Name Function
I Fibrinogen Converted to
fibrin
II Prothrombin Enzyme
III Tissue
Thromboplastin
Co factor
IV Ca++ Co factor
V proaccelerin,
Labile factor
Co factor
VII proconvertin Enzyme
VIII AHF A Co factor
30. IX AHF B Enzyme
X Trombokinase Enzyme
XI AHF C Enzyme
XII Hageman
Factor
Enzyme
XIII Fibrin stabilizing
factor
Enzyme
31. ABO Blood System
This system consists of three types of antigens
Antigen A
Antigen B
Antigen Rh
Two types of antibodies
Anti-A antibody
Anti-B antibody
ABO system forms four major types of blood groups.
The table below shows the possible combinations of
antigens and antibodies with the corresponding ABO
type ("yes" indicates the presence of a component and
"no"indicates its absence in the blood of an individual).