Histology/Epithelial Tissues

Anatomy & Physiology

Tissue

A group of similar cells that perform a specific function.

Epithelial

A body tissue that covers the surfaces of the body, inside and out

Glands

A cell, a group of cells, or an organ that produces a secretion for use elsewhere in the body or in a body cavity or for elimination from the body.

Exocrine

secreting externally

Endocrine

secreting internally

Tight Junction

seals neighboring cells together in an epithelial sheet to prevent leakage of molecules between them

Gap Junction

allows the passage of small water-soluble ions and molecules

Desmosome

joins the intermediate filaments in one cell to those in a neighbor

Basement Membrane

connects ET to CT; strong, protective barrier

Stem Cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

Simple Epithelium

single layer of cells

Stratified Epithelium

several layers of cells

Squamous

flat cells

Cuboidal

cube shaped cells

Columnar

column-shaped cells, taller than they are wide

Pseudostratified Columnar

a single layer of irregularly shaped and differently sized columnar cells

Transitional Epithelia

Allows for expansion and recoil after stretching; of several layers of cells which become flattened when stretched

Merocrine Secretion

Released by exocytosis

Apocrine Secretion

Release both cytoplasm and product, entire outer layer lost

Holocrine Secretion

Cell becomes packed with secretions and bursts