Blood Physiology

1. Physiology of Circulating Body
Fluid: Blood
 Blood- Complex fluid of cellular
elements and actual fluid
-Plasma(55%), cellular elements(45%)
Cells free fluid after clotting - serum
Plasma:
Slightly alkaline, yellowish
90%water, 10% dry matter
9 parts organic matter
cholesterol, TG, phospholipids,
fat, protein, hormone etc)
and mineral (ionized form)

3. Physiology of Circulating Body
Fluid: Blood
 Blood performs two major
functions:
1.Transport
 Oxygen and carbon dioxide
 Food molecules (glucose,
lipids, amino acids)
 Ions ( Na+, Ca2+, HCO3
−)
 Wastes (e.g., urea)
 Hormones
 Heat
2. Defense of the body

4. What’s in plasma?
Water
Nutrients
Plasma proteins- 6-8g/dl
-albumins- 4-5 g/dl
-α and β globulin-2-3gm/dl
-γ globulin (antibodies)
-fibrinogen -0.3gm/dl
Origin: all except γglobulins are formed in the liver
γ globulin in B Lymphocytes (bone marrow, lymph node)
Gases; wastes
Physiology of Circulating Body
Fluid: Blood (Plasma)

5. Physiology of Circulating Body
Fluid: Blood
Functions of Plasma protein
 Osmotic pressure (25mmHg)
= maintain plasma volume
 Viscosity
Contribute half viscosity of blood
Depends on molecular shape
Fibrinogen contribute more
 Buffer function
C terminal buffer acid and NH3
alkali
Plasma

6. Functions of Plasma protein
 Protein reserve
during starvation and depletion
 Antibodies
Gamma globulin
 Clotting
Coagulation of blood
 Transport
Hormone and other small
molecules Globulin and albumin
 Cellular components of blood
Red Blood cells
Transport Hb
Significance of biconcave shape
-Swell before burst (hypotonic sol)
-Suited for squeezing
-Large surface area to volume
ratio- efficiency of O2 transfer

7. Physiology of Circulating Body
Fluid: Blood
 Size
Mean diameter- 7.5µm
Maxm thickness 2.5µm and 0.5 to 0.8 µm
 Normal count
♂: 5.2 Million/cu mm of blood
♀: 4.7 Million/ cu mm
High altitude
 Other characteristics
Mean corpuscular volume (MCV) = 90 cu microns
Mean corpuscular hemoglobin (MCH) = 30pg

8. Physiology of Circulating Body
Fluid: Blood
 Function (of RBC)
-Hemoglobin transport
-Oxygen transport
-Carbon dioxide transport
-Buffer system
No nucleus, no mitochondria,
no Ribosome, non insulin
dependent glucose transport
Life span 120 days

9. Haemoglobin
 Gives red blood cells their
colour
-Can carry up to 4 molecules
of O2
-Associates and dissociates
with O2
-Contains iron

10. Erythropoiesis = RBC
production
Granulopoiesis =
granular WBC Production
Hemopoietic Tissues =
responsible for production
of new blood cells
Physiology of Circulating Body
Fluid: Blood
 Production of RBC
Embryonic life- yolk sac
Liver spleen, lymph node
Bone marrow of all
bones (5 yr)
Hemopoiesis = formation
of blood cells,
Fig. Relative rates of RBC production

11. Physiology of Circulating Body
Fluid: Blood
2 Types:
- Myeloid Tissue (Red Bone
Marrow) = responsible for
production of most blood cell
- Lymphatic Tissue (Thymus,
etc.) = for formation of T-
lymphocytes, proliferation of
lymphocytes
Theories of Hemopoiesis
Monophyletic Theory:
All blood cells arise from a
single common stem cell
Diphyletic Theory:
Lymphocytes &
monocytes derived from
one stem cell (lymphoblast)
, granular leukocytes and
RBCs from another stem
cell (myeloblast)
Polyphyletic Theory:

12. Genesis of RBC ( Erythropoiesis)

13. Circulating Body Fluid: Blood
Erythropoiesis

14. Stages of Erythropoiesis
Proerythroblast
large cells (20-30µm) ,
large spherical nucleus,
prominent nucleoli,
basophilic cytoplasm
Basophilic Erythroblast
still large (15-20 µm), nucleus
round and proportionately
smaller, basophilic cytoplasm,
chromatin more condensed
Erythropoiesis
Principal processes involved
in differentiation of RBC:
- Reduction in size
- Condensation and eventual
loss of nuclear material and
organelles
- Acquisition of Hb via
protein synthesis
- Loss of proliferation
capabilities

15. Polychromatophilic erythroblast
• 12-15 µm in diameter, cytoplasm with diffuse
Basophilic (blue ; ribosomes) and acidophilic (pink; Hb)
staining , nucleus spherical and proportionately smaller
with chromatin more condensed
Orthchromatic erythroblast
• 8-10 micrometers, nucleus small and dark-staining
(condensed heterochromatin), cytoplasm pinkish
blue to pink
Circulating Body Fluid: Blood
Erythropoiesis

16. Reticulocyte
• 8-10 µm , no nucleus (extrusion has occurred), more
acidophilic cytoplasm but still some basophilic due to
ribosomes
• Diapedesis
Mature erythrocytes
• cytoplasm stains completely acidophilic
differentiation & maturation by 3 days
Circulating Body Fluid: Blood
Erythropoiesis

17. Circulating Body Fluid: Blood
Regulation of Red blood
cell Production
Tissue oxygenation
Anemia, High altitude ,
Cardiac failure , pulmonary
disease, low blood volume :
RBC production
Erythropoietin
Formation of RBC
(+ erythroblastic stages)
Vit B12 Folic acid
maturation of RBC
Androgen
+ Erythropoietin production
& Potentiates the action of
EPO, direct stimulation on
erthropoeisis
Estrogen
= - erthropoeisis
Thyroxine, cortisol, GH
= + erthropoeisis

18. Circulating Body Fluid: Blood
Erythropoietin
165 aa Glycoprotein, half life
5hrs; Source- 85% kidneys, liver
Mechanism of action:
number of erythropoietin
sensitive committed stem cell
in bone marrow : production
of proerythroblast and
proliferation and development
of other stage
EPO= DNA cleavage
followed by apoptosis site
of inactivation- Liver

19. Regulation of Erythropoietin

20. Physiology of Circulating Body
Fluid: Blood
• Formation of hemoglobin