Epithelial Tissue - Histology on the Fly

Epithelial
Tissue
Simple Squamous Epithelium
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Cells
o Thin/flat squamous cells
o Lateral view
 “flattened fried eggs”
o Surface view
 “loosely fit tiles”
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Features
o 1 layer (simple)
o Perpendicular to free surface
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Function
o Fluid transport
o Gas exchange
o Organ movement
o Lining membrane
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Location
o Pulmonary alveoli
o Endothelium (blood vessels)
o Mesothelium (serous membranes)
o Glomerular (Bowman’s) Capsule
o Primordial ovarian follicles
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Video recording
o Isolated cells
o Lateral view
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Microscope images
o Isolated cells
 10x
 40x
Simple Cuboidal Epithelium
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Cells
o Cube shaped cells
o Tall as they are wide
o Spherical nuclei
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Features
o 1 layer (simple)
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Function
o Secretion
o Absorption
o Covering (ovary)
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Location
o Walls of glandular ducts
 i.e. eccrine (sweat) glands
o Kidney tubules
 i.e. proximal convoluted tubule
o Thyroid follicles
o Ovary
 Germinal epithelium
 Primary ovarian follicles
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Video recording
o Simple cuboidal epithelium
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Microscope images
o 10x
o 40x
Simple Columnar Epithelium (Ciliated)
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Cells
o Tall, rectangular cells
o Ovoid nuclei
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Features
o 1 layer (simple)
o Cilia (2-3 micrometers in length)
 Hair-like extensions located on the apical surface
 Function to move substances or objects along the apical surface
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Function
o Transportation (ciliated)
o Secretion (may have cells lined with microvilli between ciliated cells)
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Location
o Oviducts
o Uterus
o Small bronchi
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Video recording
o Simple columnar epithelium (ciliated)
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Microscope images
o 10x
o 40x
Simple Columnar Epithelium (Non-Ciliated)
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Cells
o Tall, rectangular cells
o Ovoid nuclei
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Features
o 1 layer (simple)
o Microvilli (~ 1 micrometer in length)
 Microscopic hair like extensions from the apical surface of cells
 Increase the surface area for absorption
 Usually associated with mucous glands and goblet cells
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Function
o Absorption
o Secretion (microvilli)
o Protection
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Location
o Digestive tract
o Gall bladder
o Large glandular ducts
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Video recording
o Simple columnar epithelium (non-ciliated)
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Microscope images
o 10x
o 40x
Pseudostratified Columnar Epithelium
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Cells
o Columnar cells
 Tall, rectangular cells
 Ovoid nuclei
o Goblet cells
 Mucous production
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Features
o Single layer of cells
o All cells in contact with basement membrane/lamina but only some reach
the surface causing nuclei to appear at different levels
 Gives impression of “stratified”
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Functions
o Secretion
o Absorption
o Transportation
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Locations
o Ciliated (“respiratory epithelium”)
 Trachea
 Primary bronchi
 Nasal cavity
 Auditory tube
 Lacrimal sac
o Non-Ciliated (contain stereocilia)
 Male urethra
 Epididymis
 Large excretory ducts of glands
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Video recording
o Pseudostratified columnar epithelium (ciliated)
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Microscope images
o 10x
o 40x
Stratified Squamous Epithelium (Non-Keratinized)
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Cells
o Free surface cells – nucleated squamous cells
o Deeper layers – nucleated columnar to cuboidal cells
 Basal layer –mitotically active
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Features
o Several layers (stratified)
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Functions
o Protection
o Secretion
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Location
o Esophagus
o Vagina
o Oral cavity
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Video recording
o Stratified squamous epithelium (non-keratinized)
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Microscope images
o 4x
o 10x
o 40x
Stratified Squamous Epithelium (Keratinized)
*Described in more detail in the Integument System
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Cells
o Free surface cells – dead, non-nucleated squamous cells
 Filled with protein (keratin)
o Deeper layers – nucleated columnar to cuboidal cells
 Basal layer –mitotically active
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Features
o Several layers (stratified)
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Function
o Protection
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Location
o Epidermis (skin)
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Video recording
o Stratified squamous epithelium (keratinized)
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Microscope images
o 4x
o 10x
o 40x
Stratified Cuboidal Epithelium
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Cells
o
o
o
o
Cube-shaped cells
Tall as they are wide
Spherical nuclei
Inferiormost layer can vary from columnar to cuboidal
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Features
o Rare
o Usually two layers (stratified)
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Functions
o Secretion
o Protection
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Locations
o Sweat glands
o Mammary glands
o Salivary glands
o Developing ovarian follicles
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Video recording
o Stratified cuboidal epithelium
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Microscope images
o 40x
Stratified Columnar Epithelium
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Cells
o Tall, rectangular cells
o Ovoid nuclei
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Features
o Rare
o Usually two layers
o Top layer columnar
o Deeper layers cuboidal
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Functions
o Secretion
o Protection
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Location
o Conjunctiva (eye)
o Various excretory ducts
 i.e. salivary ducts
o Regions of male urethra
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Microscope images
o 40x
Transitional Epithelium
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Cells
o Top layer – apical (cuboidal-like) cells
 Umbrella cells
 Transition to squamous with distention
o Deeper layers – columnar to cuboidal cells
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Features
o Several layers
o Top layer transitions with distention
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Functions
o Distention
o Protection
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Locations
o Urinary bladder
o Ureter
o Renal calyces
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Video recording
o Transitional epithelium
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Microscope images
o 10x
o 40x