Microscopy ✗ tissue preparation
Light microscope ( =
uses natural light)
resolving power = smallest distance between 2
particles at which they can be seen as separate objects
( Max .
012µm )
-
2 sets of lenses : •
eyepiece
•
objective
-
total magnification =
eyepiece ✗ objective
Electron microscope
-
beam is not light , it uses electron beam
-
resolution : 012 nm ( nooo ✗ better)
> transmission ITEM)
-
beam passes through specimens , image seen on fluorescent screen
> scanning ( SEM)
-
beam is scanning surface of specimen ,
not passing through
-
electron signal captured by detector
( worse resolution than TEM)
Tissue preparation
-
obtaining tissue ( biopsy / necropsy)
-
fixation ( to avoid tissue digestion , mostly formalin , osmium for SEM / TEM )
-
dehydration
-
clearing
-
wax embedding
-
-
sectioning ( paraffine sections)
-
staining ✗ mounting
methods
staining
( HE)
→ hematoxylin ✗ eosin
-
nucleus distinguished from cytoplasm
-
hematoxylin = basic dye , stains acidic structures purple ( nuclei , RER ) =
basophil ice
-
eosin = acidic dye stains basic structures pink ( cytoplasm collagen fibers) =
acidophil ic
, ,
> PAS -
reaction ( stains carbohydrates in cells )
-
polysaccharides basement membrane , mucin of goblet cells
,
, Epithelial tissue
-
covers surfaces cavities and forms glands
,
-
no or very little extracellular space ( tightly packed )
-
avascular ( no blood vessels or lymphatics present )
high regeneration
-
-
basal surface attached to basal lamina
-
covering and glandular
-
polarity of the cells :
apical domain ,
lateral domain , basal domain
v1 Iv to
connection to basal 1am
projections junctions .
basement membrane
basallaminaofepitheliumtfibrqremtiyulgarmlamn
gfunderlyingconnecttissue
-
=
( light micros c.)
> structural attachment , separation , filtration , regeneration
+ prevents cancer cells from spreading to other tissues
→ apical domain : -
microvilli ( absorbtion) immotile
-
stereocilia ( absorbtion) immotile
-
cilia ( movement) motile
→ lateral domain : -
impermeable occluding junctions C tight j .
)
-
anchoring j . I desmosome ,
zonula ad her ) .
-
communicating j .
( gap j .
,
hemidesmos )
.
→ basal domain ( basal info/ dings ) → ion
pumps
covering / lining epithelia
Layers -
simple squamous ( capillary ,
bronchi)
> simple ( single layer) -
simple cuboidal ( bite duct)
> stratified ( several sheets / layers) -
simple columnar ( uterus ,
tubes
,
intestine , stomach)
> pseudostratified ( simple , hight of cells different )
> transitional lurothel) -
pseudo str . columnar fairways epididimis) ,
-
transitional ( urothel) ( urinary bladder ) → umbrella cells
shape of cells
-
stratified squamous non keratinized Coral Cav .
, esophagus ,
-
squamous ( width greater than hight) 0 vagina ,
anal canal ,
vocal folds of larynx )
-
cuboidal 1 both same) ☐ -
Str .
squamous keratinized ( skin -
epidermis)
-
columnar ( hight greater than width) ①
! transition zone between 2 different epithelia → possible place for cancer e. g. cardio of stomach =
esophagus connects
to stomach -
different
epithelium
vagina -
uterus = cervical cancer
Light microscope ( =
uses natural light)
resolving power = smallest distance between 2
particles at which they can be seen as separate objects
( Max .
012µm )
-
2 sets of lenses : •
eyepiece
•
objective
-
total magnification =
eyepiece ✗ objective
Electron microscope
-
beam is not light , it uses electron beam
-
resolution : 012 nm ( nooo ✗ better)
> transmission ITEM)
-
beam passes through specimens , image seen on fluorescent screen
> scanning ( SEM)
-
beam is scanning surface of specimen ,
not passing through
-
electron signal captured by detector
( worse resolution than TEM)
Tissue preparation
-
obtaining tissue ( biopsy / necropsy)
-
fixation ( to avoid tissue digestion , mostly formalin , osmium for SEM / TEM )
-
dehydration
-
clearing
-
wax embedding
-
-
sectioning ( paraffine sections)
-
staining ✗ mounting
methods
staining
( HE)
→ hematoxylin ✗ eosin
-
nucleus distinguished from cytoplasm
-
hematoxylin = basic dye , stains acidic structures purple ( nuclei , RER ) =
basophil ice
-
eosin = acidic dye stains basic structures pink ( cytoplasm collagen fibers) =
acidophil ic
, ,
> PAS -
reaction ( stains carbohydrates in cells )
-
polysaccharides basement membrane , mucin of goblet cells
,
, Epithelial tissue
-
covers surfaces cavities and forms glands
,
-
no or very little extracellular space ( tightly packed )
-
avascular ( no blood vessels or lymphatics present )
high regeneration
-
-
basal surface attached to basal lamina
-
covering and glandular
-
polarity of the cells :
apical domain ,
lateral domain , basal domain
v1 Iv to
connection to basal 1am
projections junctions .
basement membrane
basallaminaofepitheliumtfibrqremtiyulgarmlamn
gfunderlyingconnecttissue
-
=
( light micros c.)
> structural attachment , separation , filtration , regeneration
+ prevents cancer cells from spreading to other tissues
→ apical domain : -
microvilli ( absorbtion) immotile
-
stereocilia ( absorbtion) immotile
-
cilia ( movement) motile
→ lateral domain : -
impermeable occluding junctions C tight j .
)
-
anchoring j . I desmosome ,
zonula ad her ) .
-
communicating j .
( gap j .
,
hemidesmos )
.
→ basal domain ( basal info/ dings ) → ion
pumps
covering / lining epithelia
Layers -
simple squamous ( capillary ,
bronchi)
> simple ( single layer) -
simple cuboidal ( bite duct)
> stratified ( several sheets / layers) -
simple columnar ( uterus ,
tubes
,
intestine , stomach)
> pseudostratified ( simple , hight of cells different )
> transitional lurothel) -
pseudo str . columnar fairways epididimis) ,
-
transitional ( urothel) ( urinary bladder ) → umbrella cells
shape of cells
-
stratified squamous non keratinized Coral Cav .
, esophagus ,
-
squamous ( width greater than hight) 0 vagina ,
anal canal ,
vocal folds of larynx )
-
cuboidal 1 both same) ☐ -
Str .
squamous keratinized ( skin -
epidermis)
-
columnar ( hight greater than width) ①
! transition zone between 2 different epithelia → possible place for cancer e. g. cardio of stomach =
esophagus connects
to stomach -
different
epithelium
vagina -
uterus = cervical cancer
