Lab 1: Skin and Epithelial Tissue Flashcards
describe H&E stain
hematoxylin and eosin
describe hematoxylin
blue-purple
basic
what structures does hematoxylin dye
dyes acidic structures which are basophilic
- DNA/nucleus, etc
describe eosin
pink
acidic
what structures does eosin dye
dyes basic structures which are acidophilic
- cytoplasm, collagen, muscle fibers, etc
what are structures dyed by eosin called
eosinophilic
name the 4 basic tissues
epithelial
connective
muscular
nervous
what are the 3 main types of epithelial tissue
simple (simple)
stratified (compound)
pseudostratified
name simple epithelial tissue (types and a location)
squamous - endothelium
cuboidal - thyroid
columnar - GI tract
name stratified epithelial tissue (types and a location)
squamous - skin
cuboidal - sweat duct
transitional - urinary bladder
where is pseudostratified found
trachea
describe characteristics of epithelial tissue
rests on a BM (basement membrane)
epithelial tissue is avascular
may be keratinized or non keratinized
what does avascular mean
lacks blood vessels
where is keratinized epithelial tissue found
epidermis
where is non keratinized epithelial tissue found
esophagus
name layers of skin
epidermis
dermis
hypodermis
where is site of BM
between epidermis and dermis
name layers of the epidermis (top to bottom, 4)
stratum corneum
stratum granulosum
stratum spinosum
stratum germinativum
describe stratum granulosum (gen/1 fact)
keratohyalin granules
name the main objectives of the microscope
scanning x4
low power x10
high dry x40
oil immersion x100 (dont use tho)
describe the condenser
condenses light into parallel beams
diaphragm - make sure numbers match objective
how to determine final magnification
multiply objective by 10 (since eyepieces are x10)
describe objectives
all are parfocal - once image is focused with low power it is almost in focus and only requires fine focusing
what type of epithelium is the epidermis
stratified squamous keratinized epithelium
what are the dermis and hypodermis made of
connective tissue
nuclei, DNA, RNA appear…
basophilic
blue
cytoplasm and proteins appear…
red
describe BM
not visible in skin - but must know general location
in between epidermis and dermis
what is epidermis lined by
basement membrane
name the first layer of cells resting on BM
stratum germinativum (stratum basale)
describe stratum germinativum
single layer of columnar shaped cells
what do cells in stratum germinativum do
actively divide
responsible for regenerating epidermis
what are cells joined to the BM by (stratum germinativum)
hemidesmosomes
describe stratum spinosum
several layers of polygonal shaped cells
what are cells joined together by (stratum spinosum)
desmosomes
why is stratum spinosum referred to as spinosum
because tonofibrils gives cells a spiny appearance
what are tonofibrils
visible fibers that insert into the cellular junctions
describe stratum granulosum
2-5 layers of cells
flattened and contain basophilic (blue) granules called keratohyalin granules
what is the surface layer called
stratum corneum
describe stratum corneum
non nucleated cells & have cytoplasm filled with keratin
what happens in stratum corneum
desmosomes begin to breakdown
cells at surface are shed (de-squamation)
