Physiology of Blood Cells and Hemostasis

PHYSIOLOGY
OF BLOOD
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

CONTENTS
• INTRODUCTION
• FUNCTIONS
• COMPOSITION
• PLASMA & ITS CONTENTS
• FORMED ELEMENTS
• HEMATOPOIESIS
• ERYTHROCYTES
• APPLIED PHYSIOLOGY
• LEUKOCYTES
• THROMBOCYTES
• HEMOSTASIS &
COAGULATION
• BLOOD GROUPING &
TRANSFUSION
• CONCLUSION

• Definition.
• Forms 6-8 % of total body wt.
• Avg adult volume:
• Males – 5-6 L
• Females – 4-5L
• pH = 7.4
• Specific Gravity = 1.052 – 1.061
• Viscosity = 3 – 5 times more viscous than
water.
INTRODUCTION

Indian Dental academy
• www.indiandentalacademy.com
• Leader continuing dental education
• Offer both online and offline dental courses

FUNCTIONS
• Respiratory
• Nutritional
• Excretory
• Homeostasis
• Defense
• Transport

COMPOSITION OF BLOOD

PLASMA
• Is a pale yellow, colloidal solution in which
cellular elements of blood are suspended.
• Normal plasma volume = 3 L
• Composition of plasma = ECF of body
except for presence of significant no. of
proteins.
• If plasma is allowed to clot, fluid left
behind after clotting = SERUM.

PLASMA
WATER 91.0%
PROTEIN 7.0%
INORGANIC
IONS
0.9%
ORGANIC
SUBSTANC
ES
1.1%

PLASMA PROTEINS
• NORMAL VALUES
Total proteins - 7.3 gm% (6.4 to 8.3gm%)
Albumin - 4.7 gm%
Globulin - 2.3 gm%
Fibrinogen - 0.3 gm%
(NORMAL) A-G Ratio: 1.7
• ORIGIN OF PLASMA PROTEINS
Embryo
– mesenchyme cells
Adults
– reticuloendothelial cells of liver
- Gamma globulin synthesized from B lymphocytes in Lymph
Nodes, Bone Marrow.

PROPERTIES
1. MOLECULAR WEIGHT
Albumin: 69,000
Globulin: 1,56,000
Fibrinogen: 4,00,000
2. ONCOTIC PRESSURE
3. BUFFER ACTION
4. ANTIBODIES
5. CLOTTING

ORGANIC SUBSTANCES OF
PLASMA
1. Proteins
2. Carbohydrates
3. Fats
4. Amino acids
5. Non protein nitrogenous substances: NH3,Urea etc
6. Internal secretions like hormones.
7. Enzymes -- amylase, carbonic anhydrase, alkaline phosphatase,
acid phosphatase.
8. Antibodies -- immunoglobulinswww.indiandentalacademy.com

• Inorganic subs. Of Plasma include = Na, K, Ca, Cl,
HCO3, PO.4
• Plasma blood levels of imp. Subs. :
GLUCOSE = 100 – 120 gm %
CHOLESTEROL = 150 – 250 mg %
BILIRUBIN = 0.5 – 1.5 mg %
CALCIUM = 7 – 11 mg %
IRON = 50 – 150 mg %

FORMED ELEMENTS

FORMED ELEMENTS
• RBC
• WBC
# Granulocytes Neutrophils(60-70%)
Eosinophils(2-4%)
Basophils(.5-1%)
#Agranulocytes- Monocytes(3-8%)
Lymphocytes(20-25%)
• PLATELETS

HEMATOPOIESIS
• Is the process of blood cell production.
• Blood forming tissues divided into 2 groups:
1. MYELOID TISSUE
2. LYMPHOID TISSUE
MYLEOID TISSUE – means red bone marrow.
it produces rbc, granulocytes
( neutrophils, eosinophils,basophils),
monocytes & platelets.
LYMPHOID TISSUE – includes lymph nodes, thymus, & spleen.
it produces lymphocytes.

• In embryo & fetus – Yolk sac
Liver
Spleen
Lymph nodes &
Red bone marrow.
• After birth – confined primarily to red bone marrow
&
some lymphoid tissue.
• All formed elements are derived from –
PLURIPOTENT STEM CELLS..www.indiandentalacademy.com

• STEM CELLS produce cells that give rise to various type
of blood cells:
• PROERYTHROBLASTS- red blood cells
• MYELOBLASTS- Granulocytes
• LYMPHOBLASTS- Lymphocytes
• MONOBLASTS- Monocytes
• MEGAKARYOBLASTS- Platelets

HEMATOPOIESIS

ERYTHROCYTES
• COMPOSITION
• MORPHOLOGY
• FUNCTIONS
• ERYTHROPOIESIS
• HEMOGLOBIN
• LIFE SPAN

• The main component of RBC is
HEMOGLOBIN
• 95 % of dry wt. of RBC = HEMOGLOBIN.
• If RBC is cut, hemoglobin is not extruded because it is interwoven
in stroma of RBC.
• Other RBC contents include - Lipids
- ATP
- CARBONIC ANHYDRASE
- NADH & NADPH
COMPOSITION

MORPHOLOGY
• Shape : circular , biconcave
• Size : 7.8 µm
• Thickness : 2.5 µm, 1 µm
• Volume : 90-95 µm3
• Surface area : 130 µm2
• Avg. count
– Male : 5.2 (4.2 – 5.8 ) million/mm3
– Female : 4.5 (3.6 – 5.2 ) million/mm3
– Infant : 6-7 million/mm3

• Large surface area
• Squeeze through capillaries
Advantages of bi-concave shape:

CELL MEMBRANE
• It contains usual material – lipids, proteins & channels.
• Some special features include :
Presence of GLYCOPHORINS- A protein material which
contains blood group antigens.
other proteins like- ACTIN
SPECTRIN
CLINICAL NOTE
SPHEROCYTOSIS- A defect in spectrin
of RBC, concavity is lost

FUNCTIONS
98.5 % with Hb
1.5 % in plasma
70 % as HCO3
23 % with Hb
7 % in plasma
Carriage of O2
Carriage of CO2

ERYTHROPOIESIS
•INTRODUCTION
•SITES
•STAGES
•FACTORS
•APPLIED

• The process by which new RBC are
produced is called as ERYTHROPOIESIS.
• It starts in 3rd
week of IUL and continues as
long as person remains alive.
• Time required to produce 1 RBC = approx.
4 days.
INTRODUCTION

SITE
• I. U Life:
– 3rd
week-3rd
month -- yolk sac
– 3rd
month-5th
month -- liver
– 5th
month onwards -- RBM
• Post-natal : Red Bone Marrow

CELL DIAMETER NUCLEUS CYTOPLASM
15-20 μm Big & strongly Very scanty & basophilic
basophilic No Hb.
11-16 μm Smaller Scanty & basophilic.
No Hb.
10-12 μm Smaller & Hb starts to appear,
Denser cytoplasm polychromatic
8-10 μm Ink spot Plentiful, eosinophilic.
nucleus increase in Hb.
8-10 μm Absent Some RNA still present.
7.5 μm Absent Hb++.
STAGES

FACTORS
1. ERYTHROPOIETIN
2. HORMONES
3. VITAMINS
4. METALS

ERYTHROPOIETIN
• Is a Glycoprotein Hormone
• MW= 36,000.
• Released from JG apparatus of kidney
when body becomes hypoxic.
• FUNCTIONS:
Stimulates precursor cells to proliferate &
differentiate
stimulates Hb synthesis in developing
RBC.
Hastens process of maturation of RBC
esp. RETICULOCYTESwww.indiandentalacademy.com

ERYTHROPOIETIN

HORMONES
1. ANDROGENS, ACTH, TSH, THYROID,
PITUITARY HORMONE – increase
erythropoiesis
2. OESTROGEN – Decreases
Erythropoiesis

ROLE OF VITAMIN B12 & FOLIC ACID
• Both are important.
• Each of these vitamins are required in a different way for formation of
THYMIDINE TRIPHOSPATE, 1 of essential building blocks of DNA.
• Lack of either 2 , causes decreased DNA & consequently failure of
nuclear maturation & division.
• So erythroblasts, fail to proliferate & differentiate into normal RBC.
• Instead, they become larger than normal RBC called as
MACROCYTES. Thin cell membrane
Irregular & large
Loss of concavity
They carry O2 normally but life is decreased as they are fragile n die
easily.

OTHER FACTORS
• VITAMIN B6 – Exact role unclear but its deficiency leads
to anaemia.
• VITAMIN C – Helps in absorption of iron.
• AMINO ACIDS – For globin part of Hb.
• IRON – Heme formation.
• COPPER & COBALT – Exact role unknown.

APPLIED PHYSIOLOGY
• Erythropioesis intensity –Reticulocyte count
– > 3% -- increased erythropoiesis
– < 0.5%-- decreased erythropoiesis
• Deficient erythropoiesis
– Bone marrow hypofunction (aplasia or hypoplasia)
– Lack of factors –Vit B12, Folate, Vit C
– Excessive blood transfusion
• Excessive erythropoiesis
– Anemia
– Excessive erthropoietin generation
• Eg. - high altitude.

HAEMOGLOBIN
• Is the red oxygen carrying pigment in RBC.
STRUCTURE : (GLOBIN PART )
• A globular protein which consists of 4 protein chains & 4 heme groups.
• 4 polypeptides are collectively called as GLOBIN part of Hb.
• 2 of them have identical AA no. & sequence, designated as ALPHA
chain (141 AA).
• Other 2 are called as BETA chains (146 AA).
• Thus formula of GLOBIN part of normal adult Hb is HbA, written as
α2β2.

HAEM PART OF Hb
• Each heme is a red pigment molecule containing 1 Fe atom.
• This Fe atom is held in a heterocyclic ring known as PORPHYRIN
(made up of 4 pyrrole rings).
• The Fe atom is the site of oxygen binding.
• Fe is present in Ferrous form in RBC & even after combining with
oxygen it is still present in Ferrous form.
Clinical note
METHEMOGLOBINwww.indiandentalacademy.com

HAEMOGLOBIN
NORMAL VALUES
• Average hemoglobin (Hb) -- 14 to 16 gm%.
• At different ages:
– At birth : 22 – 25 gm%
– After 3rd month : 18 – 20 gm%
– After1 year : 17 gm%
– In adult males : 14 – 17 gm%
– In adult females : 12 – 16 gm%
TYPES OF HEMOGLOBIN
– Adult hemoglobin-HbA —globin contains 2 α and 2 β chains
– Fetal hemoglobin-HbF -- 2 α and 2 γ chains instead of β chains.

DERIVATIVES OF HEMOGLOBIN
1. REDUCED HEMOGLOBIN OR
FERROHEMOGLOBIN
2.OXYHEMOGLOBIN
3. CARBHEMOGLOBIN
4. CARBOXYHEMOGLOBIN
5 METHEMOGLOBIN OR FERRIHEMOGLOBIN

• SYNTHESIS OF HEMOGLOBIN
– Starts in proerythroblastic stage.
– Appears only in Intermediate normoblast stage
– Heme—Succinyl Co A & glycine -- mitochondria
– Globin -- ribosomes
• DESTRUCTION OF HEMOGLOBIN
– Occurs in Phagocytes of Spleen.
– Globin is broken into AA and reused.
– Heme – its tetrapyrrole ring is opened up to form BILIVERDIN.
– its oxidation produces BILIRUBIN.

HEMOGLOBIN / RBC BREAKDOWN

CLINICAL NOTE
• Many drugs eg. METHANDROSTENOLONE, competes with
bilirubin for conjugating with glucuronides. So free bilirubin is
accumulated in plasma leading to jaundice.
• CRIGLER- NAJJAR DISEASE- GLUCURONYL TRANSFERASE
is absent, leading to jaundice.
• PHENOBARBITONE, increases activity of glucuronyl
transferase.So hyperbilirubinaemia & kernicterus in neonates can
be treated with it.

ABNORMAL HEMOGLOBIN
• Due to gene mutation -- structural variation in polypeptide chains.
– Hemoglobin S --sickle cell anemia. α chains normal & β chains
abnormal.( Glutamic acid is replaced by valine at 6th
position).
• In thalassemia, polypeptide chains are decreased, absent or
abnormal.
– In α thalassemia, α chains are decreased, absent or abnormal and
– In β thalassemia, β chains are decreased, absent or abnormal.
PORPHYRIAS- Is defective synthesis of heme.

Hb level for elective surgery
• Why Is Knowing Hb Level Before Surgery so Important?
Hb level lets us know if our body is making enough red blood cells. It is
important to know this before surgery because we may lose some blood
during or after surgery. Too few red blood cells, indicates anemia. This
increases risk of needing transfusions.
• Normal Hb counts
14-18 g/dL in men and
12-16 g/dL in women
If found to be low there are ways to increase it depending on cause of
anaemia;
If we lack certain nutrients, we may need to take supplements.
A newer method is to give Epoetin alfa(PROCRIT)

• PROCRIT helps increase the body's
natural supply of erythropoietin.
• stimulates bone marrow to produce
"progenitor" cells.
• helps increase the number of red blood
cells.
• may reduce the need for blood
transfusions.

The Task Force on Blood Component Therapy of the American
Society of Anesthesiologists: Anesthesiology. 1996;Aug.85(2)
"The principal conclusions of the task force are that red
blood cell transfusions should not be dictated by a single
hemoglobin "trigger" but, instead, should be based on
the patient's risks of developing complications of
inadequate oxygenation. Red blood cell transfusion is
rarely indicated when the hemoglobin concentration is
greater than 10 g/dL and is almost always indicated
when it is less than 6 g/dL."
“Determination of the need to transfuse pre-op patients
whose hemoglobins are between 6 g/dL to 10 g/dL
should be based on the patient's risk of complications
due to inadequate oxygenation”.

LIFE SPAN AND FATE OF RBC’S
• Average life span -- about 120 days.
• Spleen -- Graveyard of red blood cells.
• Daily 10% red blood cells, which are senile, get
destroyed in normal young healthy adults.

• ESR
• BLOOD INDICES
• VARIATIONS OF RBC’s
• GLYCOSYLATED HEMOGLOBIN
APPLIED PHYSIOLOGY

ERYTHROCYTE SEDIMENTATION RATE
• is commonly used as a medical screening test.
• also called a sedimentation rate, sed rate or
BIERNACKI REACTION.
• it’s the length of clear supernatant plasma
measured in mm after the end of 1 hr.
• The red cells form stacks called rouleaux which
settle faster.
• Increased in inflammation

• Determination
– Westergreen’s Method
– Wintrobe’ s Method
• Normal Values of
ESR
– Westergreen's Method
• Males 0 – 15 mm in 1 hr
• Females 0 - 20 mm in 1 hr

1. Specific gravity of RBC’s :
– ESR increased
2. Rouleaux formation -- Increases ESR.
– Albumin and globulin accelerate rouleaux formation. Also these 2
increase in inflammation. Therefore ESR increases in inflammatory
conditions.
3. Increased size of RBC’s -- ESR increased.
4. Viscosity of blood: ESR is reduced when viscosity more.
• SIGNIFICANCE—prognostic value
FACTORS AFFECTING ESR

• Variations of ESR
– Physiological
• Age: Less in children & infants
• Sex: F>M
• Menstruation: Increased
• Pregnancy: Increased
– Pathological
• Increases-
– TB, Anemias, Malignant tumors, RA, RF, and Liver
diseases.
• Decreases –
– Polycythemia and Extreme Leukocytosis

BLOOD INDICES
• Importance – Help in diagnosis & typing of Anaemias.
• Different Blood Indices
 Packed Cell Volume
 Mean Corpuscular Volume (MCV)
 Mean Corpuscular Hemoglobin (MCH)
 Mean Corpuscular Hemoglobin Concentration (MCHC)

PACKED CELL VOLUME
• Also called as HEMATOCRIT
• is the fraction of blood composed of
RBC
• is typically centrifuged at 10,000 RPM for
5 minutes.

• SIGNIFICANCE OF DETERMINING
PCV
– ∆ & Rx of anemia & polycythemia
(viscosity)
– recovery from dehydration after Rx
• NORMAL VALUES OF PCV
– Males = 40 to 45%.
– Females = 38 to 42%
• VARIATIONS IN PCV
– PCV increases in polycythemia and
dehydration.
– Decreases in anemia.

HEMATOCRIT VALUES

MEAN CORPUSCULAR VOLUME (MCV)
Average volume of a single red blood cell
– Normal MCV = 90 cu µ (78to 90 cu µ).
– When increased-- macrocyte
• pernicious anemia
• megaloblastic anemia
– When decreased—microcyte
• microcytic anemia

MEAN CORPUSCULAR HEMOGLOBIN (MCH)
Quantity or amount of Hb present in one RBC
– Normal value of MCH is 30 pg (27 to32pg)
– Increases or remains normal
• pernicious anemia
• megaloblastic anemia
– Decreases in hypochromic anemia.

MEAN CORPUSCULAR HEMOGLOBIN
CONCENTRATION (MCHC)
• Means the amt. of Hb present in 100 ml of RBC’s (not
100ml of blood ).
• Is of minimal diagnostic use.
• Generally noted late in course of IRON DEFICIENCY
ANAEMIA
• Relates to the color of the cells.

VARIATIONS OF RBC
• IN NUMBER
• IN SIZE
• IN SHAPE

VARIATIONS IN RBC COUNT
PHYSIOLOGICAL VARIATIONS
• Increase in count--Physiological
Polycythemia
– Age
– Sex
– High altitude
– Muscular exercise
• Decrease in count
– High barometric pressurewww.indiandentalacademy.com

PATHOLOGICAL VARIATIONS
• Decrease in no. – ANAEMIA
• Increase in no. - POLYCYTHAEMIA

ANAEMIA
• Means a def. of Hb, which can be caused
by either too few RBC or too little Hb in
RBC.
• TYPES
Iron deficiency anaemia
Blood loss anaemia
Aplastic anaemia
Megaloblastic anaemia
Hemolytic anaemiawww.indiandentalacademy.com

POLYCYTHAEMIA / ERYTHROCYTOSIS
• Means increase in RBC concn., usually with
a corresponding increase in Hb level.
TYPES:
• Primary polycythaemia / Polycythaemia Vera
• Secondary polycythaemia

VARIATIONS IN RBC SIZE
• Microcytes
– Iron deficiency anemia
• Macrocytes
– Megaloblastic anemia
• Anisocytes
– Pernicious anemia

VARIATIONS IN RBC SHAPE
1. Crenation: Shrinkage -- hypertonic solution
2. Spherocytosis: Globular -- hypotonic solution
3. Elliptocytosis: Elliptical -- certain anemias
4. Sickle cell: Crescentic -- sickle cell anemia

GLYCOSYLATED HEMOGLOBIN

• Represents glucose control averaged over a
longer time period.
• Is proportional to average blood glucose
concentration over the previous four weeks to
three months.
• Hb A1c runs 6.0% or less - good longer-term
glucose control.
• Hb A1c values - more than 7.0% - DIABETICS

THE MAPPING BETWEEN HBA1C
AND BLOOD
GLUCOSE
A1C (%) Avg. Blood Sugar (mg/dl)
5 80
6 120
7 150
8 180
9 210
10 240
11 270
12 300www.indiandentalacademy.com

LEUKOCYTES

LEUKOCYTES
• Colourless and nucleated
formed element of blood.
CLASSIFICATION
• 1. Granulocytes-with granules
– Neutrophils,
– Eosinophils and
– Basophils
• 2. Agranulocytes-without
granules.
– Monocytes and
– Lymphocytes

LEUKOPOIESIS

• NORMAL COUNT OF WHITE BLOOD CELLS
1.Total WBC count (TC): 4,000 to 11,000 /cu. mm of blood
2. Differential WBC count (DC):
• Polymorphonuclear granulocytes Mononuclear agranulocytes
Neutrophils 60-70% Lymphocytes 25-33%
Eosinophils 1-4% Monocytes 2-6%
Basophils 0.25-0.5%
• VARIATIONS IN THE COUNT OF WBC’s
– Increased count -- leukocytosis.
– Decreased count --leukopenia.

• PHYSIOLOGICAL VARIATIONS
1.Age : In infants -- 20,000 per mm3
In children-- 10,000 to 15,000 per mm3
of blood.
2. Sex: slightly more in males. In females, increases during menstruation,
pregnancy and parturition.
3. Diurnal variation: Min in early morning & max in afternoon.
4. Exercise: Increased
5. Sleep: Minimum.
6. Emotional conditions: like anxiety - count increased.
7. Pregnancy: Increased

• PATHOLOGICAL VARIATIONS
– Causes of Leukocytosis :
• pyogenic infections
• allergy
• common cold
– Causes of Leukopenia :
• typhoid
• bone marrow depression
• viral and protozoal infections
• cirrhosis of liver
• splenic disorders

NEUTROPHILS
• Size : 10- 14 µm diameter
• Nucleus : purple, multilobed
• Lobes :2,3 upto 5 or more. Young cell—less lobes.
• Cytoplasm :blue , granular
• Granules : fine, amphophilic /neutrophilic, have lytic enzyme
1. Primary/azurophilic /lysosomal –bacterial destn.
2. Secondary – lactoferrin – inhibits growth
• Life span :2-5 days

PHAGOCYTOSIS

• Functions : phagocytosis – 1st line of
defense
• Neutrophilia:
– Physiological cause :
• exercise
• lactation
• pregnancy
– Pathological cause :
• acute pyogenic infection
• Neutropenia:
– Causes :
• typhoid and viral fever
• bone marrow depression

EOSINOPHILS
• Size : 10- 14 µm diameter
• Nucleus : purple, bilobed
• Cytoplasm : acidophilic
• Granules : coarse, bright red
• contains
- major basic proteins (MBP) - histaminase
– Eosinophil peroxidase enzyme (EPO) – antibacterial
Life span : 7-12 days

• Functions :
– limit allergic intensity
• eg Bronchial asthma, hay fever
– mild phagocytosis
• Eosinophilia :
– Causes :
• allergic conditions
• parasitic infections
• Eosinopenia :
– Causes :
• injection Of corticosteroids

BASOPHILS
• Size : 10-14 µm diameter
• Nucleus : bilobed, S shaped
• Cytoplasm : basophilic, granular
• Granules : coarse, purple/ blue, plenty, contain
– Heparin
– Histamine
– Hyaluronic acid
– proteases
• Life span : 12-15 days

• Functions :
Chemotaxis
allergy
• Basophilia :
– Causes :
• chicken pox
• small pox
• tuberculosis
• influenza
• Basopenia
– Causes :
• administration of glucocorticoids

MONOCYTES
• Size : 10- 18 µm diameter (largest)
• Nucleus : pale , round/kidney shaped
• Cytoplasm : clear , pale blue , agranular
• Life span : 48-72 hrs in blood & 3 months in tissues.
• Reticuloendothelial system :
blood monocytes + tissue macrophages
MONOCYTE

• Functions :
– phagocytosis – 2nd
line of defense
– secretions of chemical activators of inflammation
• IL-1,TNFβ, binding proteins like transferrin, lysozyme, proteases, acid
hydrlase
– antigen presenting cells (APC).
– role in tissue repair
MONOCYTE

Physiology of Blood Cells and Hemostasis

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