Epithelial
Tissue
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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)