Epithelial Tissue Vocabulary

Vocabulary flashcards summarizing essential terms and properties of epithelial tissues from the lecture notes.

Epithelial Tissue (Epithelium)

A sheet of cells that covers body surfaces or lines body cavities; functions in protection, absorption, filtration, excretion, secretion, and sensory reception.

Covering and Lining Epithelium

Type of epithelium that forms outer layers of skin and lines open cavities and organs.

Glandular Epithelium

Epithelium specialized for secretion; forms the body’s glands.

Polarity (of Epithelium)

Characteristic in which cells have an apical (free) surface that differs structurally and functionally from the basal surface.

Apical Surface

The free, exposed surface of an epithelial cell or tissue.

Basement Membrane

Acellular layer of basal lamina and reticular lamina that anchors epithelium to underlying connective tissue.

Specialized Contacts

Tight junctions and other cell connections that bind epithelial cells into continuous sheets.

Avascular but Innervated

Epithelia lack blood vessels yet are supplied with nerves; nutrients diffuse from underlying tissue.

Regeneration (Epithelial)

Ability of epithelial cells to rapidly divide and replace lost or damaged cells.

Simple Epithelium

One layer of epithelial cells attached to the basement membrane; specialized for filtration, absorption, or secretion.

Stratified Epithelium

Two or more layers of epithelial cells; chiefly protective in function.

Squamous Cells

Flat, scale-like epithelial cells.

Cuboidal Cells

Box-shaped epithelial cells approximately as tall as they are wide.

Columnar Cells

Tall, column-shaped epithelial cells.

Simple Squamous Epithelium

Single layer of flattened cells; allows diffusion and filtration; lines air sacs of lungs, kidney glomeruli, blood vessels, and serosae.

Pseudostratified Columnar Epithelium

Single layer of cells of varying height giving a false stratified appearance; often ciliated and contains nuclei at multiple levels.

Transitional Epithelium

Stratified epithelium with plump, elastic cells that slide over each other; lines urinary organs and stretches as they fill.

Cilia

Motile cell projections on apical surface that move substances across epithelial surfaces.

Microvilli

Minute membrane projections that increase surface area for absorption.

Goblet Cells

Mucus-secreting unicellular glands found within some epithelial linings.

Endocrine Glands

Ductless glands that release hormones into extracellular fluid and bloodstream.

Exocrine Glands

Glands that retain ducts and secrete substances onto body surfaces or into cavities (e.g., sweat, oil, liver, pancreas).