Glycocalyx
Protective mechanical barrier associated with the cell membrane in all cells
Basal Lamina
Extracellular matrix secreted by epithelial cells, Visible only with TEM, Makes up a portion of the basement
Cell Junctions
Within Epithelium there are four types of cell junctions which in certain conditions can be observed
Hemidesmosomes
“half desmosomes” attach the basal cell membrane to the basal lamina.
Zonula adherens
Zonula adherens Linked to actin cytoskeleton
Zonula occludens
(tight junction)
Gap Junction (Nexus)
where cytoplasm of two cells communicate through tiny pores
Junctional Complex
Zonula occludens, Zonula adherens, Macula adherens, Gap junctions
Terminal Bar
All four junctions create these
Zonula adherens
Only one cell junction is unique to epithelia
Apical Projections
Microvilli, Stereocilia, Cilia
Microvilli
Actin core
Microvilli
Enhances absorption, Expand surface area of cells apex up to 10,000 times
Location of the Microvilli
Mucosal lining of most of the GI tract
Stereocilia
Lining of portion of the male reproductive tract (epididymis)
Second Stereocilia
Lining of the inner ear
CIlia
Lining of uterine portion of the female reproductive tract