Epithelial Tissue

What is Tissue?

Cells of similar type and function clustered together

• Best looked at using “histology”

Primary types

Epithelial - covers and lines

connective - provides support

muscle - enables movement

nervous - controls work

What is epithelial tissue

A sheet of cells that cover and line other tissues

• protects, covers and lines

• absorbs nutrients

• filters biochemical substances

• provides sensory input

• manufactures secretions

• manufactures excretions

Characteristics of epithelia

• organized into tightly packed groups that form sheets

• cells are avascular

• most cells are innervated by nerves

Epithelial cells can be classified by their surface area, the numbers of layers they have, their shape, and their attachments to one another.

Major types of cellular junctions

• tight junctions

• desmosomes

• gap junctions

• basement membrane

what is the cellular attachment of cells called

Junctional complexes