Epithelial Tissues Flashcards
where is epithelium tissue found
lines all body surfaces and also all internal tubes and cavities e.g mouth, cardiovascular system, skin
How does epithelium aid the immune system
acts as a barrier to prevent microbe entry
what is the apical surface
surface that is facing the lumen/ external surface
what is the basal surface
surface that is facing the interior surface/ connective tissue
tight junctions
water tight seal between adjacent cells
desmosomes
anchor adjacent cells but also allow stretch
where is simple squamous epithelium found
lines surfaces involved in passive diffusion e.g capillaries, lungs (alveoli)
where are simple cuboidal epithelium found
lining small ducts and tubules e.g ducts of salivary glands
where is simple columnar epithelium found
lining absorptive surfaces
e.g small intestine
where is pseudo stratified ciliated columnar epithelium found
airways of respiratory tract
cilia propel trapped dirt to be expelled
goblet cells
modified columnar epithelial cells that secrete mucus
scattered throughout simple columnar in the GIT and respiratory tract
transitional stratified
multiple layers of different shaped cells allowing expansion and stretch - found in the bladder
pseudo stratified
single layered however nuclei give appearance of multiple layers
always apical specialisation
How is stratified epithelium named
Named after shape of cells at apical surface
Where is stratified epithelium found
in areas needing protection from mechanical abrasion
e.g epidermis and oral cavity
Keratin
apical specialisation that may be present on stratified epithelium
provides a tough protective barrier on the apical layer (non-living)
ulceration
break in continuity of epithelium allowing microbe access. potential to be infectious
carcinoma
malignancy of epithelial tissue
