Histology of epithelial Flashcards
What is the 6 main roles of epithelial cells
Epithelial cells are involved in the linings of hollow cavities , creating physcial external barriers such as the skin to keep harmful toxins out , diseases and protection to the skin. KEY: Protection , Absorbtion , Secretion , filtration , Excretion and sensory imput
Give an example of epithelial cells role in protection and the type of epitheium involved ?
Epidermis the outermost layer of the skin involved in barrier protection , keeping internal and external evironemnts seperate .The skin is made up of startified squamous epithelium : Many layers of flat shaped cells with a keritinized layer ontop (dead cells ) waterproof and further protection
what type of epithelium is the skin made up of and why is it better suited than cuboidal or columnar ?
Cuboidal or columnar are larger and do not stack neatly as squamous , too many gaps in the skin and less layers for protection.
Absorption is a function of epithelaium where would it be found and what does it do to facilliate better absorption. What type of epithelial would be best suited ?
Absorption would be found primarily in regions of the intestines and stomach (In the GI/digestive tract ) Columnar cells are specilised in absorption of materials due to their apical specilisations microvilli.These help to increase surface area making it easier for nutreints to be absorbed. The epitheium is made up of simple cuboidal epitheium.
Do cuboidal cells absorb substances ?
Yes they do , they are more common for absorption and secretion specifically in glands and ducts as well as kidneys
what apical specilisations can columnar cells have ?
so they can be ciliated or non ciliated meaning they can either have cilia or microvilli .If they have microvilli (non motile) they are likely involved in absorption where as if they are involved in movement of mucus they will have cilia hence they will be found in the respiritory tract compared to the GI tract
Give an example of where Simple squamous would typically be found ?
Mainly involved in diffuson and filtration with some absorptive and secretion roles : since they are one cell thick they undergo alot of friction , not very protective and typcially found in Lining of blood vessels , walls of the heart and lining of alveoli
What is distinguishable about transitional epithelium?
The presence of umbrella cells and layers change becoming many layers to a fewer layers : Epithlium typically found is stratified whcih when stretched becomes flattened layer of cells near the surface.
what is pseudostratified ?
one layer which looks like many , its very rare that pseudostratified cuboidal or columnar epithelium, typically its known as pseuodtratifed columnar whcih is found in the respiratory tract : trachea, nasal cavity , lung bronchi
What are goblet cells mainly associated with ?
Where in the body would you expect to see stratified epithelial (more for protection )
Skin , vagina , tongue , anal cavity , oesophogus
where is simple cuboidal and where is startified cuboidal found ?
simple is found in ducts and and small glands kidneys where as stratified is found in glands : saliva and sweat
In which type of columnar epithelia are the nuclei not aligned at the basal end of the cell?
pseudostratified
What are keratins?
a type of protein (tough)
