Leukocytes and WBC Anomalies

Comprehensive practice flashcards covering leukocyte classification, phagocytosis mechanisms, kinetic compartments, and various WBC anomalies and inclusions mentioned in the lecture.

Leukocytes

Colorless nucleated cells that circulate normally inside the peripheral blood; synonymous with white blood cells.

Immunocytes

A classification of white blood cells involved in the production of antibodies, specifically lymphocytes.

Metamyelocyte

The stage of a neutrophil cell where the indentation of the nucleus is less than $\frac{1}{2}$.

Band or Stab

The stage of a neutrophil cell where the indentation of the nucleus is greater than $\frac{1}{2}$.

Hypersegmented neutrophil

A neutrophil with more than $5$ lobes, typically occurring in megaloblastic types of anemia.

Diapedesis

The process where cells squeeze between junctions of endothelial cells of vessel walls to move from the peripheral blood into tissues.

Primary (azurophilic) granules

Membrane-bound lysosomes that appear first in the promyelocytic stage, containing myeloperoxidase, lysozyme (muramidase), and proteases.

Secondary (specific) granules

Granules containing lysozyme, lactoferrin, specific collagenases, and Vit.B12-binding proteins, but NO PEROXIDASE.

Chemotaxis

The movement of neutrophils toward the highest concentration of chemical factors.

C5a

Considered the most potent anaphylatoxin during the recognition phase of phagocytosis.

Phagosome

A structure formed when a neutrophil's lamellopod flows around and fuses with a foreign particle or microorganism.

Degranulation

The process where cytoplasmic granules migrate to and fuse with the phagosome, releasing their contents to kill invaders.

Chediak-Higashi Syndrome

A rare congenital disorder involving a mutation in the $CHS1$ $LYST$ gene on chromosome $1q42.1-2$, leading to abnormal fusion of granules and recurrent infections.

Major Basic Protein (MBP)

An arginine-rich protein making up $50\%$ of the inner core of eosinophil granules, responsible for damaging larval cells of parasites.

Charcot Leyden crystals

Crystals associated with eosinophils and composed of lysophospholipase.

T-cells

Lymphocytes that develop in the thymus and function in cell-mediated immunity such as graft rejection and delayed hypersensitivity.

B-cells

Lymphocytes that develop in the bone marrow or bursal equivalent and perform humoral immunity through antibody production.

Pelger-Huët Anomaly (PHA)

An autosomal dominant disorder resulting from a mutation in the lamin b-receptor gene, characterized by decreased nuclear segmentation.

Pince-nez

The characteristic spectacle-like morphology of mature neutrophils in Pelger-Huët Anomaly, where bilobed nuclei are attached by a thin filament.

Myelokathexis

A component of WHIM syndrome characterized by normal granulocyte production but impaired release into circulation, resulting in neutropenia.

Alder-Reilly Anomaly

A recessive trait characterized by dark-staining metachromatic cytoplasmic granules composed of partially digested mucopolysaccharides.

May-Hegglin Anomaly

A rare autosomal dominant condition characterized by pale blue inclusions resembling Döhle bodies, giant platelets, and potential thrombocytopenia.

Döhle bodies

Gray to light blue round or oval inclusions in the peripheral cytoplasm of PMNs that are remnants of free ribosomes or rough surface ER.

Toxic granulation

Abnormally large, dark-staining primary granules (Peroxidase positive) in neutrophils associated with severe infections or toxic conditions.

Auer Rods

Red-staining, needle-like cytoplasmic inclusions in myeloblasts or promyelocytes resulting from abnormal fusion of primary granules.

Barr body

The inactive X chromosome in a female somatic cell, appearing as a drumstick-like shape projecting from a neutrophil nucleus.