Tissue Structure List

Histology

The study of tissues.

Epithelial tissue

Tissue composed of tightly packed cells with free and basal surfaces, attached to a basement membrane; covers and lines structures.

Connective tissue

Tissue that supports, binds, and protects organs and structures in the body.

Muscle tissue

Tissue specialized for contraction to produce movement.

Nervous tissue

Tissue specialized for transmitting electrical impulses and communication.

Simple

One cell layer thick; each cell attached to the basement membrane.

Stratified

More than one cell layer thick; only basal cells attach to the basement membrane.

Pseudostratified

Appears multilayered but is a single layer; all cells attach to the basement membrane but not all reach the surface.

Squamous

Flat cells with centrally located nuclei; irregular shape.

Cuboidal

Cube-shaped cells with centrally located nuclei.

Columnar

Tall, thin, column-shaped cells with variable nuclear positions.

Keratinized

Stratified squamous epithelium whose superficial cells are dead, filled with keratin, providing toughness and water resistance.

Nonkeratinized

Stratified squamous epithelium with living surface cells, often moist, providing protection without the hardened keratin layer.

Transitional epithelium

A stratified epithelium specialized to stretch, found in the urinary tract.

Simple squamous epithelium

Single layer of flat cells; lines blood vessels, lymphatic vessels, alveoli, serous membranes.

Simple cuboidal epithelium

Single layer of cube-shaped cells; found in kidney tubules, glands, ducts, ovaries, terminal bronchioles.

Simple columnar epithelium

Single layer of tall column-shaped cells; may have cilia or microvilli; lines digestive tract, gallbladder, uterus, uterine tubes.

Keratinized stratified squamous epithelium

Stratified squamous with keratinized, dead surface cells; forms epidermis of skin.

Pseudostratified columnar ciliated epithelium

Single layer of column-shaped cells of varying heights; often ciliated and with goblet cells; lines nasal cavity, pharynx, trachea, bronchi.

Apical (free) surface

The surface of epithelial cells not attached to other cells; faces lumen or outside environment.

Basal surface

The surface of epithelial cells attached to the basement membrane.

Basement membrane

Thin sheet of proteins like collagen anchoring epithelium to connective tissue.

Cilia

Finger-like projections made of microtubules extending from the apical surface; beat rhythmically to move substances.

Brush border

Dense array of microvilli on apical surface, increasing surface area for absorption.

Microvilli

Small cytoplasmic extensions with microfilaments; increase surface area for absorption.

Glycocalyx

Outer protective coat of cell membrane composed of glycolipids and polysaccharides; part of brush border.

Goblet cells

Mucus-secreting epithelial cells, usually found in columnar epithelium.

Lumen

The hollow space inside a tubular structure, lined by epithelium.