Blood Physiology Experiments

Vocabulary practice flashcards covering laboratory methods, formulas, reference ranges, cell morphology, and diagnostic principles in blood physiology experiments.

Hematocrit (PCV)

The ratio of shaped blood elements (blood cells) to the total blood volume, determined following centrifugation in capillary tubes.

Hematocrit Ruler

A measurement device used to read packed cell volume by aligning the base of the settled red blood cells with the $0$ mark and the top of the plasma meniscus with the $100$ mark on the scale.

Erythrocyte Dilution Pipette

A specialized pipette containing a red bead used to draw blood up to the $0.5$ line and Hayem solution up to the $101$ line to yield a $1:200$ dilution for erythrocyte enumeration.

Hayem Solution

An isotonic diluting solution used in erythrocyte counting that preserves red blood cell structure while filling the dilution pipette up to line $101$.

Thoma Counting Chamber (Neubauer Slide)

A heavy glass slide featuring a precision grid of defined area and depth ($\frac{1}{10}\,\text{mm}$ deep, $\frac{1}{400}\,\text{mm}^2$ area per small square) used under a microscope for manual cell counts.

Thoma Grid Edge Counting Rule

A standard counting protocol where cells located within the square or touching its left and upper boundaries are counted, whereas cells touching the right and bottom boundaries are omitted.

Erythrocyte Count Formula

$\text{Number of Erythrocytes (in } 1\,\text{mm}^3\text{)} = \frac{\text{Erythrocytes counted} \times 200 \times 4000}{80} = \text{Erythrocytes counted} \times 10000$, derived from counting $5$ medium squares ($80$ small squares total).

Leucocyte Dilution Pipette

A glass pipette containing a white bead used to draw blood to the $1$ line and Türk solution to the $11$ line to prepare a $1:10$ dilution for leukocyte counts.

Türk Solution

An acid-based diluting fluid that hemolyzes mature non-nucleated erythrocytes while staining the nuclei of leukocytes, drawn to line $11$ during white blood cell counting.

Leucocyte Count Formula

$\text{Number of Leucocytes (in } 1\,\text{mm}^3\text{)} = \frac{\text{Leucocytes counted} \times 10 \times 4000}{400} = \text{Leucocytes counted} \times 100$, based on scanning the entire ruled grid area.

Sahli's Hemoglobinometer

A manual diagnostic apparatus comprising a graduated hemoglobin tube, a $20\,\mu\text{l}$ ($0.02\,\text{ml}$) capillary pipette, a glass stirrer, and permanent colored comparison standards for assessing hemoglobin levels.

Acid Hematin (Hemin Chlorur)

The brown-pigmented compound formed when blood hemoglobin reacts with $0.1\,\text{N}\;\text{HCl}$ in Sahli's hemoglobin tube, which is subsequently diluted with distilled water until matching the comparator block.

Mean Corpuscular Volume (MCV)

A Wintrobe index quantifying average erythrocyte volume, calculated as $\text{MCV}\,(\mu^3) = \frac{\text{Hematocrit} \times 10}{\text{Number of Erythrocytes}}$, used to define normocytic, microcytic, or macrocytic conditions.

Mean Corpuscular Hemoglobin (MCH)

A Wintrobe index measuring average hemoglobin content per red blood cell by weight, determined as $\text{MCH}\,(\text{picogram}) = \frac{\text{Hemoglobin} \times 10}{\text{Number of Erythrocytes}}$.

Mean Corpuscular Hemoglobin Concentration (MCHC)

A Wintrobe index evaluating the mean concentration of hemoglobin within a unit volume of packed erythrocytes, calculated as $\text{MCHC}\,(\%) = \frac{\text{Hemoglobin} \times 100}{\text{Hematocrit}}$.

Blood Smear (Froti)

A thin layer of blood spread evenly across a microscope slide, dried, and treated with Romanowsky stains such as May-Grünwald-Giemsa or Giemsa to evaluate cell morphology and blood parasites.

Leucocyte Formula (Differential Count)

A procedure in which $100$ consecutive white blood cells are counted and classified ($10$ cells per field across stepped rows) to calculate relative percentages of each leukocyte type.

Neutrophil

The most prevalent granulocyte characterized by pale pink-blue cytoplasm, segmented or banded purple nuclei, and phagocytic activity against acute bacterial infections; referred to as heterophils in avian species.

Eosinophil

A granulocyte possessing prominent reddish cytoplasmic granules (noted for a blackberry-like appearance in horses) whose count varies during stress, allergic conditions, and parasitic infestations.

Basophil

The least numerous leukocyte ($0.5\text{--}1\%$ of circulating WBCs) densely packed with coarse, dark blue cytoplasmic granules that synthesize and release heparin and histamine during chronic inflammation.

Lymphocyte

A mononuclear agranulocyte featuring a spherical, dark purple nucleus occupying almost the entire cell, functioning in antibody-mediated humoral immunity (B cells) and cell-mediated immunity (T cells).

Monocyte

A large mononuclear phagocyte exhibiting an irregular cellular border, grayish-blue cytoplasm, and a light purple horseshoe-shaped indented nucleus, elevated in chronic infections.

Tissue Thromboplastin

A procoagulant factor released from traumatized epidermal tissue during skin puncture, necessitating the disposal of the very first drop of capillary blood to prevent premature clotting artifacts.

Fibrin Threads

Polymerized strands of insoluble fibrin that stretch across broken segments of an unheparinized capillary tube, marking the endpoint of the manual coagulation time measurement.

Erythroblastosis Fetalis

A hemolytic condition triggered when maternal Anti-D antibodies from an Rh-negative mother cross the placenta to bind and destroy Rh-positive fetal red blood cells, causing compensatory release of immature erythroblasts.

NESTROFT

An acronym for Naked Eye Single Tube Red cell Osmotic Fragility Test, a rapid screening protocol for erythrocyte fragility using EDTA-anticoagulated blood in hypotonic saline.

Minimal Durability (Osmotic Fragility)

The specific salt concentration at which initial red blood cell lysis begins, identifiable by the earliest appearance of a faint reddish tint in the tube supernatant.

Maximal Durability (Osmotic Fragility)

The salt concentration at which complete erythrocyte lysis occurs, characterized by a completely clear, transparent wine-red solution with no remaining intact cells.