Hematology is the study of blood and its components, including blood cells and coagulation. The three main types of blood cells are red blood cells, white blood cells, and platelets. Red blood cells transport oxygen and carbon dioxide, white blood cells protect the body from infection, and platelets control hemostasis and initiate blood clotting. Laboratory safety precautions must be followed when working with blood and bodily fluids to prevent infection and injury. Standard/universal precautions require treating all human blood and tissues as potentially infectious.

1. PREPARED BY:
LGG, RMT
HEMATOLOGY 1
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OVERVIEW OF
HEMATOLOGY

2. What is hematology?
● includes the study of blood cells and coagulation.
● It encompasses analyses of the concentration, structure, and function of cells in
blood
● their precursors in the bone marrow
● the chemical constituents of plasma or serum intimately linked with blood cell
structure and function
● the function of platelets and proteins involved in blood coagulation.
HEMA = blood
LOGY = study
- study of blood and its components
● The average human possesses 5 liters of blood.
● Blood transports oxygen from lungs to tissues; clears tissues of carbon dioxide;
transports glucose, proteins, and fats; and moves wastes to the liver and kidneys.
An Overview of Clinical Laboratory Hematology
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3. ● There are 3 types of blood cells:
1. Red blood cell (erythrocyte)
2. White blood cell (leukocyte)
3. Platelets (thrombocytes)
● The liquid portion of the blood is called plasma, which transports coagulation enzymes
that protect vessels and maintain the circulation plasma carries and nourishes blood cells.
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4. SAFETY IN THE HEMATOLOGY LABORATORY:
● Many conditions in the laboratory have the potential for causing injury to staff and damage
to the building or to community.
● patient’s specimen, needles, chemicals, electrical equipment, reagents, and glassware all
can be potential causes of accidents or injury.
● managers and employees must be knowledgeable about safe work practices and
incorporate these practices in to the operation of the hematology laboratory.
● the key to prevention of accidents and laboratory-acquired infections is a well-defined safety
program.
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5. UNIVERSAL (STANDARD) PRECAUTION
● In December 1991, the Occupational Safety and Health Administration (OSHA) issued the
final rule for the “Occupational Exposure to Bloodborne Pathogens” standard.
● the standard that specifies universal (standard) precautions to protect laboratory workers
and other healthcare professionals became effective on March 6, 1992.
● Universal was the original term; OSHA’S current terminology is universal (standard)
precautions.
STANDARD PRECAUTIONS
Standard precautions - requires that all human blood, body fluids, and tissue be treated as if
they were infectious, must be adopted by the laboratory.
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6. RED BLOOD CELLS
● Highly specialized cell responsible for oxygen and carbon transport
● Normal body function requires that a minimum of 3.09 x 10¹¹ RBCs per kilogram of body
mass be in circulation.
● Anucleate, biconcave, discoid cells filled with a reddish protein, hemoglobin (HGB).
● Pink to red and measure 6 to 8 mm in diameter with a zone of pallor that occupies one
third of their center = Biconcave
● Hematocrit is the ratio of the volume of packed RBCs to the volume of whole blood.
- also called packed cell volume (PCV), the packed cells referring to RBCs.
● RBC INDICES:
1. MCV = Mean cell volume expressed in fL (femtoliter)
2. MCH = Mean cell hemoglobin expressed in pg (picogram)
3. MCHC = Mean cell Hemoglobin Concentration expressed in g/dL

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WHITE BLOOD CELLS
● dedicated to protecting their host from infection and injury.
● WBC count ranges from 4500 to 11,500/mL.
● A decreased WBC count (fewer than 4500/mL) is called leukopenia.
● increased WBC count (more than 11,500/mL) is called leukocytosis
● TYPES OF WBCs:
1. Neutrophil
- also known as segmenters, polymorphonuclear neutrophils (PMNs)
- phagocytic cells whose major purpose is to engulf and destroy microorganisms and
foreign material, either directly or after they have been labeled for destruction by
the immune system.

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WHITE BLOOD CELLS
- term segmented refers to their multilobed nuclei.
- increase in neutrophils is called neutrophilia, often signals bacterial infection.
- A decrease is called neutropenia and has many causes, but it is often caused by
certain medications or viral infections.
2. Lymphocyte
- comprise a complex system of cells that provide for host immunity.
- Lymphocytes recognize foreign antigens and mount humoral (antibodies) and
cell-mediated antagonistic responses.
- An increase in the lymphocyte count is called lymphocytosis and often is associated
with viral infections.
- An abnormally low lymphocyte count is called lymphopenia or lymphocytopenia and
is often associated with drug therapy or immunodeficiency.

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WHITE BLOOD CELLS
3. Monocytes
- immature macrophage passing through the blood from its point of origin, usually the bone
marrow, to a targeted tissue location.
- Their tasks are to identify and phagocytose (engulf and consume) foreign particles and
assist the lymphocytes in mounting an immune response through the assembly and
presentation of immunogenic epitopes.
- An increase in the number of monocytes is called monocytosis.
- Monocytosis may be found in certain infections, collagen-vascular diseases, or in acute and
chronic leukemias

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WHITE BLOOD CELLS
4. Eosinophil
- are cells with bright orange-red, regular cytoplasmic granules filled with proteins involved
in immune system regulation.
- elevated eosinophil count is called eosinophilia and often signals a response to allergy or
parasitic infection.
5. Basophils
- are cells with dark purple, irregular cytoplasmic granules that obscure the nucleus.
- basophil granules contain histamines and various other proteins.
- An elevated basophil count is called basophilia. Basophilia is rare and often signals a
hematologic disease.

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PLATELET
● or thrombocytes, are true blood cells that maintain blood vessel integrity by initiating
vessel wall repairs
● Platelets rapidly adhere to the surfaces of damaged blood vessels, form aggregates with
neighboring platelets to plug the vessels, and secrete proteins and small molecules that
trigger thrombosis, or clot formation
● are the major cells that control hemostasis.
● 2 to 4 mm in diameter
● round or oval, anucleate.
● Elevated platelet counts, called thrombocytosis, signal inflammation or trauma but convey
modest intrinsic significance.

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13. THANK YOU
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