Tissues

Chapter 5

Bio160

Epithelial Tissue

• Epithelial Tissue

Location

– Covers body surface = epidermis

– Lines hollow organs, cavities, ducts, tubes (like blood vessels)

– Forms glands (sweat, salivary, oil)

Epithelial Tissue

Characteristics

– Very little intercellular (extracellular) substance between cells

– No blood vessels

– Free surface contacts air or fluid (this means that the cell’s free surface does not contact another cell at this surface, but instead contacts air/fluid)

Epithelial Tissue– Basement membrane connects epithelium

to underlying connective tissue

– Cells very readily divide, because epithelium is subject to abrasion

Epithelial Tissue

Classification according to shape of cell at the free surface:

– Cuboidal

– Squamous (thin, flat)

– Columnar

Epithelial Tissue

Classification according to number of cell layers:

– Stratified (2 or more layers)

– Simple (one layer)

Epithelial TissueSpecific names of tissues

– Simple Squamous Epithelium

Epithelial Tissue– Simple Columnar Epithelium

Epithelial Tissue

– Simple Cuboidal Epithelium

Epithelial Tissue

– Stratified Squamous Epithelium

Epithelial Tissue

– Pseudostratified Ciliated Columnar Epithelium

Epithelial Tissue

– Transitional Epithelium