Hematology and Clinical Pathology Flashcards

Flashcards covering terminology, cell types, morphological abnormalities, and laboratory calculations from the Hematology lecture notes.

Hematology

The study of blood and the tissues responsible for the formation, storage, and circulation of blood cells.

Buffy Coat

The middle layer in a vial of anticoagulated blood that contains leukocytes (WBCs) and platelets.

Plasma

The fluid portion of blood that still contains clotting factors; the top layer in an anticoagulated tube.

PCV (Packed Cell Volume)

The measurement of the percentage of red blood cells in the blood, also known as Hematocrit ($Hct$).

Serum

The fluid portion of blood that remains after the sample is allowed to form a clot, removing clotting elements.

Seven Formed Elements

The components of blood including RBCs (erythrocytes), neutrophils, basophils, eosinophils, lymphocytes, monocytes, and platelets (thrombocytes).

Central Pallor

The lighter-colored center of a mammalian RBC; it is most pronounced in canine cells.

Heterophils

The name for neutrophils in avian, amphibian, reptile, rabbit, chinchilla, and guinea pig species.

Eosinophilic

The characteristic of granules to attract eosin, the red dye used in staining.

Basophils

Rarely seen WBCs most common in equine blood; they contain purple granules and initiate acute inflammatory reactions.

Lymphocytes

The most common WBC seen in ruminants and lab animals; they vary in size and include B and T types for immune response.

Monocytes

The largest WBCs with pleomorphic nuclei and foamy, bluish-gray cytoplasm containing vacuoles; they function as macrophages in tissues.

Megakaryocytes

Bone marrow cells whose cytoplasmic fragments form platelets (thrombocytes).

EDTA

The anticoagulant found in purple top tubes, used for mammalian CBCs and blood smears.

Sodium Heparin

The anticoagulant found in green top tubes, preferred for avian, reptilian, and amphibian blood smears.

Sodium Citrate

The anticoagulant found in blue top tubes, used for coagulation profiles.

Blood Volume Estimation

The calculation that blood volume is approximately $5$ to $11\%$ of body weight, with $7\%$ being the average.

Leukocytosis

An increase in the number of WBCs above the normal reference range.

Leukopenia

An abnormally low number of WBCs below the normal reference range.

Leukemoid Response

The presence of abnormal WBCs in circulating blood in the absence of neoplasia.

Band Neutrophil

An immature neutrophil with a nucleus that has no lobes or segments.

Barr Body

A drumstick-like appendage of the nucleus seen only in females, representing an inactivated X chromosome.

Dohle Bodies

Bluish cytoplasmic inclusions in neutrophils that represent remnants of the rough ER; they are the earliest sign of toxic change.

Left Shift

A condition where increased demand for neutrophils causes the bone marrow to release a greater percentage of immature forms.

Regenerative Left Shift

A state where neutrophilic leukocytosis is present and immature forms are fewer than or equal to mature adult forms.

Rouleaux Formation

The arrangement of RBCs in columns or stacks like coins; normal in horses but can be a handling artifact.

Agglutination

The clumping of RBCs caused by antibody coating, which does not disperse when saline is added.

Anisocytosis

A variation in the size of RBCs in a blood film.

Polychromasia

The presence of RBCs with a faint blue color, usually representing immature cells like reticulocytes.

Spherocytes

Microcytic, hyperchromic RBCs that have lost their central pallor; associated with immune-mediated hemolytic anemia (IMHA).

Schistocyte

An irregular RBC fragment caused by mechanical damage to the cell membrane.

Howell-Jolly Body

A single, round, randomly located fragment of the nucleus retained within an RBC.

Heinz Body

A refractile inclusion on or in the RBC associated with toxic oxidative damage; commonly seen in healthy cats.

Basophilic Stippling

Small blue dots in RBCs representing scattered material; associated with ruminant blood or lead poisoning.

MCV (Mean Corpuscular Volume)

An index expressing the average volume of individual RBCs, calculated as $\frac{PCV \times 10}{\text{Total RBC count}}$ and expressed in femtoliters ($fL$).

MCHC (Mean Corpuscular Hemoglobin Concentration)

An index determining the hemoglobin concentration in the average RBC, calculated as $\frac{Hb \times 100}{PCV}$ and expressed in $g/dL$.

Absolute WBC Count

The total value for each specific WBC type, calculated by multiplying the percentage from the differential count by the total WBC count ($WBCs/cu\,mm$).

Corrected WBC Count

A calculation used when nRBCs are present: $\frac{\text{Total WBC count} \times 100}{100 + \text{nRBC count}}$.

DIC (Disseminated Intravascular Coagulation)

A serious complication involving generalized concurrent intravascular thrombosis and bleeding.

Erythropoietin

A hormone produced by the kidneys that communicates with the bone marrow to stimulate RBC production.