ASC101 Lab 3: Microscope Basics and Histology

Vocabulary flashcards covering microscope components, histology preparation, staining techniques with Hematoxylin and Eosin, orientation effects, and morphological epithelial cell types.

Upright Compound Light Microscope

The most common form of microscope used in undergraduate science courses, utilized for examining tissue histology and biological fluids like blood, urine, or semen.

PrimeCam

A free app available for iOS and Android that streams live video from the microscope's embedded camera system to a phone or tablet.

Histological Section Thickness

Thin tissue slices mounted on glass slides, typically $4\,\mu\text{m}$ thick, which is $25$ times thinner than a human hair.

Three-Dimensional Tissue Orientation Effect

The effect where slicing tissue thin reduces its structure to two dimensions, making the visual appearance of complex 3D structures dependent on their orientation relative to the section cut.

Hematoxylin

A basic or positively charged dye that interacts strongly with acidic, negatively charged cellular components like DNA, staining nuclei a blue to purple color.

Basophilic

Descriptive term for acidic cellular components that interact strongly with and stain using basic dyes like hematoxylin.

Eosin

An acidic dye that binds to basic or positively charged cellular components, such as cytoplasm and extracellular proteins containing arginine and lysine, staining them pink or orange.

Eosinophilic

Descriptive term for basic or positively charged cellular components that stain strongly with acidic dyes like eosin (also referred to as acidophilic).

Cuboidal Cells

Epithelial cells characterized by a roughly square cross section and centrally located nuclei.

Columnar Cells

Epithelial cells with a rectangular cross section and abundant cytoplasm, typically involved in secretion or absorption and often possessing surface structures such as microvilli or cilia.

Squamous Cells

Relatively flat epithelial cells organized horizontally (named from the Latin word for scales) that present a minimal cross section to facilitate passive diffusion.

Simple Epithelia

Epithelial cells arranged in a single layer, functioning primarily to facilitate absorption or filtration.

Stratified Epithelium

Epithelial cells arranged in multiple layers, creating a substantial protective barrier at the expense of absorptive efficiency.

Keratinization

A process in stratified epithelia where the outermost cell layers undergo terminal differentiation, losing their nuclei and filling with fibrous proteins like keratin to resist abrasion and chemical damage.

Epithelial Type Schematics and Histology

Diagrams and corresponding tissue section examples depicting simple cuboidal, simple columnar, simple squamous, stratified, and keratinized epithelial structures.