Epithelial
Tissue
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2
Characteristics
Fit
closely together to form continuous
sheets.
Has an apical surface which is a free
surface that is exposed to the body’s
exterior or to the cavity of an internal
organ.
Has a basement membrane which is
where the lower surface is attached.
No blood supply or avascular.
Can regenerate themselves easily.
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Classification of Epithelium
Arrangement
Simple
– one layer
of cells
Stratified – more
than one cell layer
Shape
Squamous
–
flattened
Cuboidal – cubeshaped like dice
Columnar –
shaped like
columns
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Types of Simple Epithelial Cells
Simple
squamous
Simple cuboidal
Simple columnar
Pseudostratified columnar
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Simple Squamous Epithelium
Single
layer of thin squamous cells
Lines air sacs of lungs, walls of capillaries
and forms the serous membranes
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Squamous Epithelium
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Simple Cuboidal Epithelium
Single
layer of cuboidal cells
Found in salivary glands and pancreas
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Simple Cuboidal Epithelium
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Simple Columnar Epithelium
Single
layer of tall cells
Goblet cells (produce
a lubricating mucus)are
often present
Lines entire digestive
tract from stomach to
anus
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Simple Columnar Epithelium
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Pseudostratified Columnar
Single
layer of columnar cell with different
heights giving it a multiple layer look.
Goble cell often present
Cells found in the respiratory tract have
cilia (ciliated).
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Pseudostratified Columnar
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Types of Stratified Epithelia
Stratified
squamous
Stratified cuboidal
transitional
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Stratified Squamous Epithelium
Several
layers of squamous cells with
either cuboidal or columnar cells near the
basement membrane.
Found in the esophagus, mouth, and
outer portion of the skin.
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Stratified Squamous Epithelium
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Stratified Cuboidal & Stratified
Columnar Epithelia
Rare
Found
mainly in the ducts of large glands
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Stratified Cuboidal & Stratified
Columnar Epithelia
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Transitional Epithelium
Highly
modified, stratified squamous
epithelium found in the bladder, ureters,
and part of urethra.
Cells change shape to adapt to
considerable stretching.
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Transitional Epithelia
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Glandular Epithelium
Endocrine
Has no connection to the surface – ductless
glands
Ex. Thyroid, adrenal, pituitary
Exocrine
glands
glands
Secretions empty through the ducts to the
epithelial surface
Ex. Sweat and oil glands (external surface),
liver and pancreas (internal surface)
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