Lecture 4- Basic Tissues Flashcards
what are the 4 basic tissues?
epithelia
connective tissue
muscle
nervous
where is epithelia located?
covers surfaces
lines cavities and tubes
forms glands
examples of where epithelia is found
skin, mouth, tubes (blood vessels)
what are the 4 important characteristics of epithelia?
attachment (loosely packed cells supported by a basement membrane)
avascularity (contains no blood vessels)
regeneration
polarity (apical and basal)
where does the apical membrane of epithelia face
lumen
where does the basal side of epithelium face
basement of the membrane
what is classification of epithelia based on?
number of cell layers and the shape of cells
simple epithelium
one layer
stratified epithelium
two or more layers
what are the 3 shapes of epithelia
squamous (flat)
cuboidal (cube)
columnar (rectangle)
what are the 6 main types of epithelia?
Simple squamous
Keratinised stratified squamous
Non keratinized stratified squamous
Simple cuboidal
Simple columnar
Pseudostratified stratified columnar with goblet cell
2 features of simple squamous
flat cells- oval shaped nuclei
one layer of cells
what is the major function of simple squamous
exchange of nutrients and gases
where is simple squamous located?
blood vessels and alveoli (smooth flow for less resistance)
3 features of keratinised stratified squamous
-flat surface cells with oval-shaped nuclei
-many layers
-keratin sits on the upper surface of the epithelium
what is the major function of keratinised stratified squamous
protection, barrier, waterproof
where is keratinised stratified squamous epithelium found
skin, gums and hard pallet where more abrasion occurs
2 features of non-keratinised stratified squamous epithelium
flat surface cells with oval-shaped nuclei
-many layers
major function of non keratinised stratified squamous epithelium
protection, barrier
where is non keratinised stratified squamous located
oral cavity, oesophagus
2 features of simple cuboidal epithelium
square cells with round nuclei
one layer
what is the major function of simple cuboidal epithelium
secretion and absorption
where is simple cuboidal epithelium located
glands and kidney tubules
what is microvilli
projections of the cytoplasm increasing the SA for absorption
what are the 2 features of simple columnar epithelium
tall cells with oval, basally located nuclei
one layer
what is the major function of simple columnar epithelium
absorption and secretion
4 features of pseudostratified ciliated columnar epithelium
-tall cells
-appears stratified some cells don’t reach the free surface
-all cells touch the basement membrane
-cilia and goblet cells