Epithelia Flashcards
Simple epithelium examples
Simple squamous, simple cuboidal, simple columnar, simple pseudostratified columnar
Stratified epithelium examples
Stratified squamous, stratified cuboidal, stratified columnar, transitional epithelium
Simple squamous epithelium function
Passive transport of substances across cytoplasm
E.g. alveoli, vessels, body cavities
Simple cuboidal & columnar epithelium function
Secretion & absorption
Simple cuboidal: thyroid, kidney, lung, ovary & ducts
Simple columnar: intestine, female reproductive tract, exocrine glands
Simple pseudostratified epithelium function
Secretion & movement of particles along tubular organs
E.g. trachea, bronchi, epididymis
Stratified squamous epithelium function
Most common multilayered epithelia, covers most external & some internal body parts
Protection of underlying tissues & prevent their desiccation
Stratified cuboidal & columnar epithelia function
Not abundant
Cover areas of transition between simple & stratified epithelia
E.g. respiratory tract, ducts of exocrine glands
Transitional epithelium function
Only in urogenital system
E.g. renal pelvis, ureter, urinary bladder & urethra
Major classes of cell junctions
Adherent junctions - cells bind to each other & to connective tissue
Tight junctions - cells involved in control of what enters body
Gap junctions - cells must communicate with each other
Paraffin procedure to prepare tissue sample
- tissue collection
- fixation & trimming
- dehydration using alcohols
- paraffin embedding
- sectioning with microtome
- straightening sections on water bath
- transferring sections to slide
- Staining & coverslipping
Describe Haematoxylin & eosin staining
Haematoxylin stains blue & mainly genetic material (DNA, RNA)
Eosin stains pink & mainly proteins (mainly cytoplasm)
