Lab week 1: Introduction to blood smear analysis

These 100 vocabulary flashcards cover microscope components, blood smear preparation and evaluation techniques, white blood cell and platelet estimation, red blood cell development (erythropoiesis), morphology, and nucleated red blood cell correction formulas based on the lecture transcript.

Eyepieces (oculars)

The parts of the microscope you look through to observe the specimen.

Interpupillary control

The microscope component that adjusts the distance between the eyepieces to match the user's eyes.

Optical tube

The structural part of the microscope that connects the eyepieces to the objective lenses.

Neck (arm)

The part of the microscope that supports the optical tube and connects it to the base.

Stand

The base of the microscope that provides stability.

Revolving nosepiece

The rotating part of the microscope that holds the objective lenses.

Objective lens

The lenses closest to the specimen that provide various levels of magnification.

Stage

The flat platform where the slide is placed for observation.

Focus controls

Knobs used to move the stage or objective lenses to sharpen the image of the specimen.

Condenser

The lens system located under the stage that focuses light onto the specimen.

Aperture diaphragm control lever

A lever used to adjust the amount of light and contrast passing through the condenser.

Stage controls

Knobs used to move the stage mechanically in the X and Y directions.

Field diaphragm

An adjustable opening that controls the diameter of the light beam entering the condenser.

Light source

The lamp located at the base of the microscope that provides illumination.

Peripheral blood smear preparation angle

Typically held at a $45^\text{o}$ angle when making the smear.

Application point

The initial spot on the slide where the blood drop is placed before spreading.

Body

The main portion of the blood smear located between the application point and the monolayer.

Monolayer

The specific area of the blood smear where cells are spread out in a single layer, ideal for morphology evaluation.

Feathered edge

The thin, terminal end of the blood smear.

Reading Area

The portion of the smear, typically the monolayer, used for microscopic examination.

Too Thick area

A region of the smear where cells are overlapping, making morphology review difficult.

Too Thin area

A region of the smear where cells are too sparse for proper evaluation.

Artifacts

Abnormal structures or changes in cells on a smear that are not naturally present but created during preparation.

10x objective

The objective used for the initial scan of the blood smear.

40x objective (high-dry)

The objective lens used to perform a WBC estimate.

100x objective (Oil Immersion)

The objective used for PLT estimation, morphology, and WBC differentials.

Platelet (PLT) estimate

Performed using the $100\times$ objective lens under oil immersion.

WBC differential and morphology

Future lab tasks performed using the $100\times$ objective lens.

RBC morphology

Evaluation of red blood cell appearance performed using the $100\times$ objective.

Neutrophil

A type of white blood cell identified on a peripheral blood smear.

Monocyte

A large white blood cell characterized by a specific cytoplasm and nuclear shape.

Eosinophil

A white blood cell often identified by its prominent reddish-orange granules.

Lymphocyte

A type of white blood cell typically smaller than monocytes with a large nucleus.

Basophil

A white blood cell characterized by dark, coarse granules.

Red blood cell (RBC) number

The first of nine items to evaluate on a blood smear.

Red cell size

A criteria for smear evaluation relating to the diameter of RBCs.

Red cell shape

A criteria for smear evaluation relating to the morphology of RBCs.

Red cell color

A criteria for smear evaluation often indicating hemoglobin content.

Inclusions

Internal structures or substances found inside red blood cells.

Platelet number

The assessment of total platelets present on the smear.

Platelet morphology

The evaluation of the appearance and structure of platelets.

White blood cell count

The estimation or enumeration of the total WBCs on the smear.

White blood cell morphology

The evaluation of the appearance and structure of WBCs.

WBC Estimation methodology

Scan 10 fields at $40\times$, count WBCs in each, then calculate the average.

WBC Estimation calculation

$$Average field count \times 2000 \rightarrow \text{estimated WBC count per } mm^3$$

Lab-validated factor for WBC

The value used in WBC estimation, which is $2000$, depending on smear quality.

Platelet Estimation methodology

Scan 10 fields at $100\times$ oil immersion near the feathered edge and count platelets in each.

Platelet Estimation calculation

$$Average field count \times 20000 \rightarrow \text{estimated PLT count per } mm^3$$

Platelet clumps

A finding that must be reported during platelet estimation if observed.

Hemocytometer

A device used for manual cell counts of body fluids.

Conditions for Hemocytometer use

Used when counts are too low for automated counters or for highly viscous fluids.

Hemocytometer manual methods

Techniques that require advanced technical skills and have poor reproducibility.

Hemocytometer Calculation Formula

$$Cell count total = rac{ ext{Number of cells Counted} imes ext{Dilution Factor}}{ ext{Volume Counted}}$

Impro Neubauer Hemacytometer

A specific type of counting chamber grid mentioned in the transcript.

Hemocytometer counting rule

Cells touching the top or left ruling are counted in; cells touching the bottom or right are out.

Erythropoiesis

The process of red blood cell development.

Hemocytoblast

The stem cell at the beginning of erythropoiesis.

Pronormoblast

The earliest recognizable RBC precursor, also called a Proerythroblast.

Basophilic normoblast

The second stage of RBC development, also called an Early normoblast.

Polychromatophilic normoblast

An intermediate stage of RBC development, also called an Intermediate normoblast.

Orthochromic normoblast

The final nucleated stage of RBC development, also called a Late normoblast.

Reticulocyte

An immature red blood cell that has lost its nucleus but still contains RNA.

Erythrocyte

A mature red blood cell.

Normal RBC Side view thickness

$$2.0 \text{ }\mu m$$

Normal RBC Top view diameter

$$7.5 \text{ }\mu m$$

Spherocyte

An RBC that is spherical in shape rather than a biconcave disk.

Micro-spherocyte

A very small, spherical red blood cell.

Irregularly contracted cell

An RBC with an abnormal, non-uniform shape.

Elliptocyte

An oval or cigar-shaped red blood cell.

Dacrocyte

A red blood cell shaped like a teardrop.

Target cell

An RBC with a dark center, a light ring, and a dark outer ring, resembling a target.

Schistocyte

A fragmented piece of a red blood cell.

Echinocyte

A red blood cell with blunt, evenly spaced projections, also called a crenated cell.

Acanthocyte

A red blood cell with irregular, thorny projections.

Sickle cell

An RBC that has transformed into a crescent or sickle shape.

S-Cocyte

A specific morphological variant of a red blood cell mentioned in the text.

Microcytic

A term describing red blood cells that are smaller than normal.

Hypochromic

A term describing RBCs that have a central pale area larger than one-third of the cell's diameter.

Macrocytic

A term describing red blood cells that are larger than normal.

Anisocytosis

A medical term for having red blood cells of unequal sizes.

CD34+ cells

The progenitor cells from which red blood cell development begins.

Pronormoblast focus points

Size, nuclear chromatin pattern, nucleoli, cytoplasm color, and N:C ratio.

Basophilic normoblast nucleoli

In this stage, nucleoli are described as having none.

Nucleated red blood cells (NRBCs)

Immature RBCs that are mistakenly counted as WBCs by automated procedures.

NRBC Reporting

Reported as the number of NRBCs per $100$ WBCs.

NRBC Correction criteria

The automated WBC count must be corrected if there are more than $5$ NRBCs per $100$ WBCs.

WBC Correction Rule

Do not correct the estimated WBC count; only the automated WBC count.

Corrected WBC Count Formula

$$\text{Corrected WBC Count} = \frac{\text{WBC count} \times 100}{\text{NRBC} + 100}$$

Corrected WBC example calculation

For $14,200 \text{/}\mu L$ WBC and $21$ NRBC: $(14,200 \times 100) / (100 + 21) = 11,800 \text{/}\mu L$.

Polychromasia

The term used for reticulocytes when seen on a slide stained with Wright's stain.

Reticulocyte staining

Identified specifically using methylene blue stain.

Pronormoblast color of cytoplasm

One of the five features to pay attention to during evaluation.

Orthochromic Normoblast identification

Focus on size, nuclear chromatin pattern, lack of nucleoli, cytoplasm color, and N:C ratio.

Manual WBC Method

Requires a hemocytometer and is used when automated counts are inaccurate.

WBC Count Unit (SI)

$$\times 10^9 \text{/L}$$

PLT Count Unit (SI)

$$\times 10^9 \text{/L}$$

Hemocytometer Corner square size

$1 \text{ } mm \times 1 \text{ } mm$ as indicated on the counting grid.

Interrupillary control purpose

To adjust the microscope so the user sees a single image through both eyepieces.

Aperture diaphragm function

Adjusts the light contrast for better visualization of cell morphology.

Oil Immersion objective

The $100\times$ objective lens used for high-detail hematology work.