This document provides an overview of hematology, including the anatomy and functions of blood components. It discusses the three main cellular elements - erythrocytes, leukocytes, and platelets - and how they are suspended in plasma. Key points covered include the structures and roles of erythrocytes in oxygen transport, leukocytes in immunity, and platelets in hemostasis. It also outlines the components and clinical significance of a complete blood count test.

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