1. Introduction to Hematology
Annette Baker, MS, PA-C
Objectives
• At this end of this lecture the student will know:
• The anatomy of blood
• The function of plasma
• The structure and function of erythrocytes,
leukocytes, platelets and hemostasis
Introduction
• Represents about 8% of total body weight
• Average volume of 5 liters in women
• Average of 5.5 liters in men
• Consists of three types of cellular elements
• Erythrocytes, leukocytes and platelets
• These are suspended in complex liquid called
plasma

2. Introduction
• 99% of cells are erythrocytes
• Hematocrit or packed cell volume is defined as
the percentage of total blood volume occupied by
erythrocytes
• Plasma accounts for the remaining volume
• Hematocrit averages 42% for women and 45% for
men
Plasma
• Functions of plasma are carried out by plasma
proteins
• Composed of 90% water
• Plasma is able to absorb and distribute much of
the heat generated metabolically within tissues
• Most abundant electrolytes in the plasma are Na
and Cl
Plasma
• Three groups of plasma proteins:
• Albumin
• Globulin
• Fibrinogen

3. • These are classified according to various
physical and chemical properties
• Plasma proteins establish osmotic gradient
between blood and interstitial fluid
Plasma
• Responsible for the plasma’s capacity to buffer
changes in pH
• Contribute to blood viscosity
• Used as metabolic fuels in starvation states
• Albumin the most abundant contribute most
extensively to the colloid osmotic pressure
• There are three subclasses of globulins: alpha,
beta and gamma
Plasma
• Alpha and beta globulins bind and transport substances
• Affects the process of blood clotting
• Regulates the role of salt balance in the body
• Gamma globulins are immunoglobulins that defends the body
• Fibrinogen key factor in blood-clotting process

4. Erythrocytes
• Primary function to transport oxygen transport
in the blood
• 5 billion erythrocytes clinically in a red blood
cell count
• Hemoglobin is transported by erythrocytes
• Hemoglobin consists of two parts
Erythrocytes
• Hemoglobin combines with carbon dioxide to
transport gas from tissue to lungs
• Buffers acid so that it minimally alters the pH of
the blood
• Carbon monoxide
Erythrocytes
• Bone marrow replaces worn-out erythrocytes
• Spleen destroys red blood cells
• Erythropoiesis is the generation of new red
blood cells

5. • Erythrocytes are generally produced by the yolk
sac first
Erythropoiesis
• Erythropoietin is produced by the kidney
• Immature red blood cells are called
reticulocytes
• Red bone marrow can be found in adults in the
sternum, vertebrae, ribs, upper end of the long
bones, and base of the skull
Leukocytes
• Also known as white blood cells
• Mobile units of the body’s immune defense
system
• Function outside the blood
• Leukocytes work by phagocytosis
Leukocytes
• Five different types of leukocytes
• They lack hemoglobin; colorless unless stained

6. • Five types of circulating leukocytes are:
neutrophils, eosinophils, basophils, monocytes, and
lymphocytes
Leukocytes
• Polymorphonuclear granulocytes are the
neutrophils, eosinophils and basophils
• Monocytes and lymphocytes are known as
mononuclear agranulocytes
• Monocytes are larger of the two
• Lymphocytes the smallest
Leukocytes
• Produced at varying rates depending on the
changing defense needs of the body
• Leukocytes originate from undifferentiated stem
cells in the red bone marrow
• Granulocytes and monocytes are produced only
in the red bone marrow
Hemopoiesis
• All blood-cell types ultimately originate from
the same undifferentiated pluripotent stem cells
• Bone marrow produces all circulating blood cells
except lymphocytes

7. • These are produced by lymphoid tissue
Leukocytes
• Neutrophils accompanies bacteria infection
• Eosinophils associated with allergic conditions
and internal parasite infestations
• Basophils dispersed in the connective tissue
• Basophils secrete histamine and heparin
• Monocytes are phagocytes
Lymphocytes
• Provide immune defense against targets
• Two types of lymphocytes
• B and T

8. • B lymphocytes produce antibodies
• T lymphocytes destroy cell-mediated immune
response
Platelets
• Bone-marrow-bound cells known as
megakaryocytes
• Derived from undifferentiated stem cells
Complete Blood Count
• Also known as CBC
• Provides detailed information about three types
of cells in the blood: red blood cells, white blood
cells and platelets
• Blood cells made from bone marrow
• Measures white blood cell count, red blood cell
count, hemoglobin, hematocrit and platelet count
CBC
• WBC (White Blood Cell) count measured in
thousands per cubic milliliter (K/mm3) of blood
• Normal range: 3.4-9.6 K/mm3
• RBC measured in millions/cubic millimeter
(mil/mm3) of blood

9. • RBC: 4.5-6.0 mil/mm3 males; 4.0-5.5 mil/mm3
in female
CBC
• Hemoglobin measured in grams per deciliter
(g/dl) of blood
• Hgb range is 13.5-17.5 g/dl for males
• Hgb range is 12.5-15.5 g/dl for females
• Hematocrit is the percentage of red blood cells
in relation to your total blood volume
• HCT 41%-52% male and 36%-48% female
Indices
• MCV: average red cell volumes
• Measured in fl
• Value 80-100 fl
• MCH: average red cell hemoglobin concentration
• Measured in picograms
• Values: 27-32 pg
Indices

10. • MCHC: compares the weight of hemoglobin in a
red cell to the size of the cell
• Reported in percentage or g/dl
• Values: 33-38 percent
CBC
• Leukopenia- decrease in number of leukocytes
in blood
• Leukocytosis – increase in number of leukocytes
in blood
• Neutropenia- decrease neutrophil count
• Neutrocytosis- increase neutrophil count
CBC
• Anisocytosis: markedly different sizes of red cell
• Poikilocytosis: significantly variation in shape of
the erythrocytes
• Macrocytosis increase in size of cell
• Microcytosis decrease in size of cell
• Helmet cell membrane injured cells found in
certain conditions
CBC

11. • Spherocytosis: dense stained red cells lacking in
central pallor
• Diameter less than normal sized red cells
• Target cells: have central are of hemoglobin
pigment surrounded by relatively clear are and
peripheral rim of hemoglobin to center of cell