EPITHELIUM

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EPITHELIAL TISSUE
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EPITHELIAL TISSUE

• 1- Epithelial membranes (Epithelia).
• 2- Glands.

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EPITHELIAL TISSUE

• General characteristics
• 1- Have cells with little intercellular space.
• 2- are avascular.
• 3- Are separated from the underlying C.T.
• by the basement membrane.
• 4- Apical surface modifications
• a- Microvilli (brush
  border).
• b- Cilia.
• 5- Are derived from ectoderm, endoderm or
  mesoderm.

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Parameters for classificationof epithelial
membranes

• (1) The shape of most superficial cells
• a- squamous (flat)
• b- cuboidal
• c- columnar

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• (2)The Number of cell layers
• a- Simple
• b- stratified

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• (3) Function
• a- Protection
• b- Absorption
• c- Secretion
• d- Excretion
• e- Transport
• f- Sensory reception

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TYPES OF EPITHELIAL MEMBRANES

• (A) Simple Epithelium
• 1- Simple squamous epithelium
• 2- Simple cuboidal epithelium
• 3- Simple columnar epithelium
• a- with cilia b- without cilia
• 4- Pseudostratified columnar epith.
• a- with cilia b- without cilia

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TYPES OF EPITHELIAL MEMBRANES

• (B) Stratified epithelium
• 1- Str. Squamous epith.
• 2- Str. Cuboidal epith.
• 3- Str. Columnar Epith.
• 4- Transitional epith.

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MICROVILLI
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CILIA
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SIMPLE EPITHELIUM
D. Pseudo-stratified columnar epith.
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STRATIFIED EPITHELIUM
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C. Str. Cuboidal epith. D. Str. Columnar epith.
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Simple squamous epithelium
Endothelium
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Simple squamous epithelium
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Simple cuboidal epithelium
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Simple cuboidal epithelium
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Simple Columnar Epithelium
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Pseudostratified columnar epithelium
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Non-keratinized Stratified Squamous epithelium
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Keratinized stratified squamous epithelium
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Transitional Epithelium
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GLANDS
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CLASIFICATION OF GLANDS

• Glands are classified according to the following
  parameters
• Presence or absence of ducts
• Exocrine.
• Endocrine.
• (2) No. of cells
• Unicellular e.g. Goblet cell.
• Multicellular.

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CLASIFICATION OF GLANDS

• (3) Nature of secretion
• Serous serous acini
• Mucous mucous acini
• Seromucous Seromucous acini
• Aqueous (watery)
• Fatty
• Waxy

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CLASIFICATION OF GLANDS

• (4) Mechanism of secretion
• a- Merocrine (by exocytosis)
• b- Apocrine
• c- Holocrine

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CLASIFICATION OF EXOCRINE GLANDS

• (5) Branching of duct Shape of secretory unit
• - Simple
• - Simple branched
• - Compound branched
• - Tubular
• - Alveolar (acinar)
• - Tubuloalveolar

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TYPES OF EXOCRINE GLANDS
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GOBLET CELLS
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GOBLET CELLS
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GOBLET CELLS
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GOBLET CELLS
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MAJOR SALIVARY GLANDS
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SEROUS, MUCOUS SEROMUCOUS ACINISEROUS
DEMILUNEMYOEPITHELIAL CELLS
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SEROUS ACINAR CELL
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SEROUS ACINI
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MUCOUS ACINI
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MUCOUS ACINI
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