Epithelial Tissue

Epithilial tissue

type of tissue that lines the interior and exterior body surfaces

types of epithelial tissue

Outer layer of skin, lining of stomach, and lining of urinary bladder

Apical surface

Not attached to surrounding tissue and exposed to either the outside of the body or the lining of an organ

Basal surface

attached to basement membrane (underlying connective tissue)

Basement membrane

In between the epithelial and connective tissue

The structure of epithelial tissue is...

Avascular but innervated

Shape classifications

squamous, cuboidal, columnar

Layer classifications

simple, stratified, pseudostratified

Squamous

flat cells

Cuboidal

cube shaped

Columnar

column shaped

Simple

one layer of cells

Stratified

multiple layers

Pseudostratified

This type of epithelial tissue appears to have multiple layers but all cells are in contact with the basement membrane (one layer)

Simple Squamish

-resembles a tile floor

Function: thin to allow for diffusion

Location: found in the lungs and blood vessels

simple cuboidal

Function: secretion and absorption

Location: Walls of glands and kidney tubules

Simple columnar

-tall closely packed cells

Function: absorption and secretion of mucus

Location: lines the digestive tract

Stratified Squamous

-many layers of flat cells

Function: protect protection from abrasion

Location: skin mouth, esophagus, and vagina

stratified cuboidal

-Very rare

Location: found in the dust of sweat, glands, and mammary glands

Stratified columnar

-Rare

Location: found in the pharynx and male urethra

Transitional

-forms the lining of urinary organs, uterus, urinary bladder, and part of the urethra

Function: stretches easily (to allow urine to stretch the bladder)

Pseudostratified columnar

Function: secretes substances, such as mucus and propel's particles for using cilia

Location: found in the trachea and fallopian tubes