Ch. 1 - An Overview of Clinical Laboratory Hematology Flashcards
The average human possesses how many liters of blood?
5L
Enumerate functions of the blood
Transports oxygen from the lungs to tissues
Clears tissues of carbon dioxide
Transports glucose, proteins, and fats
Moves wastes to the liver and kidneys
What is the liquid portion of blood? This is also responsible for the transport and nourishment of blood cells.
Plasma
Enumerate the three families of blood cells
Red blood cells (RBC) or erythrocytes
White blood cells (WBC) or leukocytes
Platelets or thrombocytes
The study of blood cells and of the liquid and cellular portion of the blood hemoglobin functions, disorders, and significance.
Hematology
What are the uses of hematology?
To predict, detect, and diagnose blood diseases and many systemic diseases that affect blood cells.
The scientist who described “worms” in the blood in the year 1657
Athanasius Kircher
The scientist who gave an account about the RBCs in the year 1674
Anton van Leeuwenhoek
The scientist who described platelets as “petite plaques” during the late 1800s
Giulio Bizzozero
Developer of the Wright stain during the year 1902
James Homer Wright
It is known as the heart of blood cell identification
Wright’s Romanowsky-type stain
A type of mixture composed of acidic (stains basic components: cytoplasm) and basic (stains acidic components: nucleus) dyes
Polychromatic
What is the scientific term for cell appearance? This encompasses cell color, size, shape, cytoplasmic inclusions, and nuclear condensation.
Morphology
These are anucleate biconcave cells filled with a reddish protein which transports oxygen and carbon dioxide.
Red blood cells (RBC)
Reddish protein found within the RBCs
Hemoglobin (Hb, HGB)
Cells that appear pink to red and measure 6-8 um in diameter with a zone of pallor covering one third of their center
RBCs
A condition wherein there is a loss of oxygen carrying capacity by the RBCs; often reflected in a reduced RBC count
Anemia
A condition where there is an increased RBC count reflecting increased body RBC mass (a condition that leads to hyperviscosity)
Polycythemia
In counting RBCs, a tiny aliqout of whole blood must be mixed with _____. This saline concentration matches the osmolality of normal blood.
0.85% (normal) saline
A pipette designed to provide the typical dilution for RBC counts which is 1:200
Thoma pipette
The diluted blood was transferred to a counting chamber or _____.
Hemacytometer
Enumerate the units used in reporting RBC count
Cells per:
Microliter (mcL)
Milliliter (mL) or Cubic Centimeter (cc)
Liter (L)
Patented the first electronic counter during the year 1953
Joseph and Wallace Coulter (Coulter counter)
What is the Coulter principle that is still being used for RBC counting in many automated hematology profiling instruments.
Direct current electrical impedance
Hemoglobin measurement relies on a weak solution called _____. This is used in manual and most automated applications.
Drabkin reagent
The Drabkin reagent is composed of _____ and _____.
Potassium cyanide
Potassium ferricyanide
An aliquot of whole blood mixed with a measured amount of Drabkin reagent converts hemoglobin to _____.
Cyanmethemoglobin (Hemiglobincyanide)
The solution of an aliquot of whole blood and Drabkin reagent is placed in a photometer with incident light at what wavelength?
540 nm
To reduce environmental cyanide, some automated hematology profiling instruments use a formulation of the ionic surfactant (detergent) _____.
Sodium dodecyl sulfate
This is the ratio of the volume of RBCs to the volume of whole blood
Hematocrit (HCT)
This is determined by transferring blood to a graduated plastic tube, centrifuging, measuring the column of RBCs, and dividing by the total length of RBCs plus plasma.
Hematocrit (HCT)
What is the normal ratio of Hematocrit?
50%
Aside from Hct, hematocrit is also known as _____.
Packed cell volume
In the name “Packed cell volume”, what does the “packed cell” refer to?
RBCs
This is a light-colored layer between the RBCs and plasma.
Buffy coat
The buffy coat contains _____ and _____.
WBCs
Platelets
Enumerate the four RBC indices.
Mean Cell Volume (MCV)
Mean Cell Hemoglobin (MCH)
Mean Cell Hemoglobin Concentration (MCHC)
RBC Distribution Width (RDW)
Enumerate the three numerical results used to compute for the RBC indices.
RBC Count
Hemoglobin
Hematocrit
The RBC indice that, although is a measurement of volume, reflects RBC diameter on a Wright-stained blood smear
Mean Cell Volume (MCV)
What is Mean Cell Volume (MCV)?
An RBC indice that, although is a measurement of volume, reflects RBC diameter on a Wright-stained blood smear
The RBC indice that expresses the mass of hemoglobin and closely reflects the MCHC.
Mean Cell Hemoglobin (MCH)
What is Mean Cell Hemoglobin (MCH)?
An RBC indice that expresses the mass of hemoglobin and closely reflects the MCHC.
The RBC indice that reflects RBC staining intensity or degree of palor.
Mean Cell Hemoglobin Concentration (MCHC)
What is Mean Cell Hemoglobin Concentration (MCHC)?
An RBC indice that reflects RBC staining intensity or degree of palor.
The RBC indice that expresses the degree of variation in RBC volume.
RBC Distribution Width (RDW)
What is RBC Distribution Width (RDW)?
An RBC indice that expresses the degree of variation in RBC volume.
The RBC indice that is based on the standard deviation of RBC volume and is routinely reported by automated cell counters but cannot be provided using manual RBC measurements
RBC Distribution Width (RDW)
Extreme RBC volume variability, which is visible on the Wright stained blood film as variation on diameter, is called _____.
Anisocytosis
RBC variation of shape is called _____.
Poikilocytosis
What are the parameters that are used to detect, diagnose, assess the severity of, and monitor the treatment of anemia, polycythemia, and numerous systemic conditions that affect RBCs.
RBC count Hemoglobin Hematocrit Indices RBC Morphology
In the Wright-stained film, the 1% to 2% of RBCs that exceed the 6 - 8 um average diameter and stains slightly blue-gray are called _____. These are newly released form the RBC production site.
Polychromatophilic erythrocytes
Where is the RBC production site?
Bone marrow
Polychromatophilic erythrocytes are closely observed because they indicate _____ during blood loss and certain anemias.
Bone marrow regeneration
Young RBCs are counted and differentiated using methylene blue dyes called _____ or _____.
Nucleic acid stains
Vital stains
These are dyes that are absorbed by live cells.
Nucleic acid stains
Vital stains
_____ are young RBCs that contain ribonucleic acid (RNA) that was highlighted using vital stains.
Reticulocytes
These not-really-blood-cells, are a loosely related grouping of cell families dedicated to protecting their host from infection and injury. They are nearly colorless in an unstained cell suspension.
White blood cells (WBC)
Leukocytes
An extreme increase in the WBC count imparts a milky appearance to the blood during this disease.
Chronic leukemia
What are the instruments used to visually count WBCs?
Microscope
Hemacytometer
Thoma pipette
The typical dilution for RBC counting is 1:_____ while it is 1:_____ in WBC.
200
20
The diluent for WBC counting is composed of _____ in normal saline.
Dilute acetic acid
This causes RBCs to lyse and rupture.
Dilute acetic acid
What is the range of normal WBC count?
4,500 - 11,500/mcL
The condition wherein there is decreased WBC count (fewer than 4,500/mcL).
Leukopenia
The condition wherein there is increased WBC count (more than 11,500/mcL).
Leukocytosis
What must be used to differentiate the families of WBCs transported in the blood?
Wright-stained blood film
Light microscopy
What are the types of WBCs?
Granulocytes (Segs/PMNs, bands, eosinophils, basophils)
Lymphocytes
Monocytes
These are cells whose sole purpose is to engulf and destroy bacteria that have been earlier labeled as harmful by the immune system.
Polymorphonuclear neutrophils
Segmented neutrophils
Segs
An increase in segs is called _____.
Neutrophilia
Neutrophilia signals what type of infection?
Bacterial infection
A decrease in segs is called _____.
Neutropenia
What causes neutropenia?
Long-term drug administration
Viral infection
These are cells that are part of the seg family but are less differentiated or less “mature”.
Band neutrophils
Bands
An increase in bands signals what type of infection?
Bacterial infection
Bacterial infection signaled by an increase in bands is called _____.
Left shift
What part of the segs and bands contains submicroscopic, pink-staining granules filled with bactericidal secretions?
Cytoplasm
A type of WBC that has bright orange, regular cytoplasmic granules filled with anti-histamine.
Eosinophils
EOs
An increase in eosinophils is called _____.
Eosinophilia
Eosinophilia signals a response to _____ or _____ infection.
Allergy
Parasitic
These are cells with dark purple, irregular cytoplasmic granules that obscure the nucleus.
Basophils
Basos
An elevated basophil count is called _____.
Basophilia
Basophilia is rare and often signals what type of disease?
Hematologic disease, such as leukemia
Although different in functions, segs, bands, eosinophils, and basophils are collectively referred to as granulocytes due to their prominent _____.
Cytoplasmic granules
This disease is referred to as an uncontrolled proliferation of WBCs.
Leukemia
This type of WBC comprise a complex system of cells that provide for host immunity. They recognize foreign antigens and mount antibody (humoral) and cell-mediated antagonistic responses.
Lymphocytes
What would be the features of most lymphocytes under a Wright-stained film?
Nearly round
Slightly larger than RBCs
Have round featureless nuclei
Thin rim of nongranular light blue cytoplasm
An increase in lymphocyte count is called _____.
Lymphocytosis
Lymphocytosis is usually associated with what type of infections?
Viral
A decrease in lymphocyte count is called _____.
Lymphopenia
Lymphocytopenia
Lymphocytopenia is assocciated with _____ or _____.
Long-term drug therapy
Immunodeficiency
A type of leukemia prevelant in people older than 70 years
Chronic lymphocytic leukemia
The most common form of childhood leukemia
Acute lymphoblastic leukemia
A type of WBC that is an immature macrophage passing through the blood from its point of origin, usually the bone marrow, to a targeted prime locatioin.
Monocytes
Monos
These are the most abundant cells in the body although they are a minor component of the blood film differential count. They occupy every body cavity; some are motile and some immobilized.
Macrophages
Their task is to identify and phagocytose (engulf) foreign particles and assist lymphocytes in mounting an immune response through the assembly and presentation of immunogenic epitopes.
Macrophages
What are the features of the monos under a Wright-stained film?
Slightly larger diameter than other WBCs
Gray cytoplasm
Lobulated nucleus
An increase in the number of monocytes is called _____.
Monocytosis
Monocytosis is associated with what type of disease?
Hematologic, leukemia
Although seldom used, decreased mono count is called _____.
Monocytopenia
Leukemia related to granulocytes
Chronic myelogenous (granulocytic) leukemia Acute myeloblastic leukemia
Leukemia related to lymphocytes
Chronic lymphocytic leukemia
Acute lymphoblastic leukemia
Leukemia related to monocytes
Chronic or acute monocytic leukemia
These are true blood cells that maintain blood vessel integrity by instigating vessel wall repairs and control hemostasis.
Platelet
Thrombocytes
What is thrombosis?
Clot formation
These cells 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.
Platelets
This is a series of cellular and plasma-based mechanisms that seals wounds, repairs vessel walls, and maintains vascular patency (condition of blood vessels not being blocked or obstructed).
Hemostasis
These cells are 2-4 um in diameter, round or oval, anucleate and slightly granular.
Platelets
This condition is responsible for deep vein thrombosis, pulmonary emboli, acute myocardial infarctions (heart attacks), cerebrovascular accidents (strokes), peripheral artery disease, and repeated spontaneous abortions (miscarriage).
Uncontrolled platelet and hemostatic activation
Counting of the platelets is confined to what part of the hemacytometer?
Center square millimeter
What type of microscopy would make it easier to identify platelets in a hemacytometer?
Phase microscopy
A condition wherein there is elevated platelet counts. This signals inflammation or trauma but carry small intrinsic significance.
Thrombocytosis
This is a rare malignant condition characterized by extremely high platelet counts and uncontrolled platelet production. It is a life-threatening hematologic disorder.
Essential thrombocythemia
A condition wherein there is low platelet count. It is a common consequence of drug treatment and may be life-threatening. Usually accompanied by easy bruising and uncontrolled hemorrhage.
Thrombocytopenia
Who can take a blood sample for a complete blood count?
Medical laboratory scientist Phlebotomist Nurse Physician Patient care technician
The term used to describe an inappropriate anticoagulant-to-specimen ratio.
Short draws
The scientist who will obtain the blood sample for CBC is responsible for the integrity of the specimen and must ensure that it is free from _____, _____ and _____.
Clots
Hemolysis
Short draws
It is the process of ensuring that the specimen is fresh enough for accurate analysis and then accurately registering the specimen in the work list.
Specimen accession
These are cells that are structural and do not flow in the blood stream; the endodermal cells that form the inner surface of the blood vessel.
Endothelial cells
Give three importance of endothelial cells.
Maintaining normal blood flow
Snaring platelets during times of injury
Enables WBCs to escape from the vessel to the surrounding tissue when called upon.
