Histology- Epithelial Tissue Flashcards
Epithelial Tissue Function:
-covers exposed surfaces
-lines internal passageways & chambers
-forms glands
-physical protection
-control permeability
-provide sensation
Epithelia:
-layers of cells that cover internal or external structures
Glands:
-structures that produce fluid secretions
-either attached to or derived from epithelia
Epithelia Characteristics:
-cells bound closely together
-polarity (differences between exposed(apical) and attached (basal) surfaces
——-attached to basal lamina (basement layer w connective tissue)
-avascular
-cells continuously replaced quickly
Classification of Epithelia:
-cell shape (squamous, cuboidal, columnar)
-number of cell layers (simple, stratified)
Squamous Epithelia:
-thin, flat, irregular
Simple Squamous Epithelia Functions:
-absorption and diffusion
OR
-slick slippery surface
Simple Squamous Epithelia Locations:
-alveoli
-mesothelium
-endothelium
Mesothelium:
-simple squamous epithelium
-lines body cavities
ex. pleura, pericardium
Endothelium:
-simple squamous epithelium
-lines heart and blood vessels
Stratified Squamous Epithelia Functions:
-protects where mechanical stresses are severe
Stratified Squamous Epithelia Locations:
-skin
-lining of mouth
-esophagus
-anus
-vagina
-keratin
—> tough and water resistant
Simple Cuboidal Epithelia Functions
-secretion & absorption
Simple Cuboidal Epithelia Location:
-lines portions of kidney tubules
Stratified Cuboidal Epithelia Functions
-rare
-form glands
Stratified Cuboidal Epithelia Location:
-sweat, salivary, and mammary ducts
Transitional Epithelia Functions:
-tolerated repeated cycles of stretching and recoiling
-returns to previous shape without damage
Transitional Epithelia Location:
-Urinary bladder
-when empty, tissue appears with many layers & superficially plump (like cuboidal cells)
-when full, tissue appears flattened (like simple epithelium)
Simple Columnar Epithelia Function & Location:
-absorption and secretion
-small and large intestine
(secretions protect against chemical stresses)
Pseudostratified Columnar Epithelia Function:
-varying shapes and functions(based on location)
ex. (absorption and secretion, protection, transport)
Ciliated Pseudostratified Columnar Epithelia Location::
-nasal cavity
-respiratory airways
-reproductive tract
—-> fallopian tubes, vas deferens??
Stratified Columnar Epithelia Function:
-protection
Stratified Columnar Epithelia Location:
-portions of pharynx
-epiglottis
-anus
-urethra
