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Lecture #6 (15-2-2017)
Lecture name: Buthainah Al masaeed
Edited by: Yaqeen Jousef
Epithelial tissue
How to name the epithelial tissues :
Surface feature
1-ciliated
2-keratinized
Number of layer
1-simple : one layer
2-stratified : two or more
Shape of the
superficies layer
1-squamous
2-cobidal
3-columnar
Glandular
Specialized epithelium tissue that
secretions : e.x.,( protein hormone ,steroid hormone, enzymes) .
1-even though I have many feature in the cell ex .microvilli and
stereocilia , increase the surfaces area but it is not motile original
(cannot move) .
2-microvilli in small intestine ,sterocilia(same microvilli but longer)
in epididymis of the male reproductive system .
3- motile original is the cilia.
4-non-keratinize just in stratified squamous epithelium.
5-if we have non-ciliated or non-keratinize don’t enter in the label
name.
Simple:
1-simple squamous epithelium:
Function: exchange
Description: single layer of flat cells with disc-shaped nuclei
Special types:
1-Endothelium (in Blood vessels)
2-Mesothelium (Around the heart and lungs and produce flowed to
address shocks)
In alveolar (lungs)
in the kidney
2-simple cuboidal epithelium:
Function: secretion and absorption.
Description: single layer of cube-like cells with large, spherical central
nuclei.
Location: kidney tubules, secretory portions of small glands,
ovary & thyroid follicles
*there are no cilia and no keratinized.
Basement membrane
3-simpe columnar epithelium:
In this type we have ciliated.
Function:
• Absorption; secretion of mucus, enzymes, and other
substances
• Ciliated type propels mucus or reproductive cells by
ciliary action
Description:
Single layer of column-shaped (rectangular) cells with
oval nuclei, Some bear cilia at their apical surface, May
contain goblet cells
In small intestine we have microvilli, and in Unique place
we have cilia in fallopian tube of female.
4- Pseudostratified Columnar Epithelium(Gives false impression of
stratification so its simple)
Function: secretion of mucus; propulsion
of mucus by cilia
This type have cilia ,conditions: goblet cell
,cilia ,different level of nuclei .(ciliated
Pseudostratified Columnar Epithelium).
Note : ciliated Pseudostratified Columnar Epithelium in nasal cell .
Stratified:
Major function is protection.
1- Stratified Squamous Epithelium
Description: Many layers of cells – squamous in shapeDeeper layers of
cells appear cuboidal or column ,Thickest epithelial tissue – adapted
for protection
Specific types :
 Keratinized – contain the protective protein keratin
Surface cells are dead and full of keratin ,forms epidermis(the first
layer of the skin).
 Non-keratinized – forms moist lining of body openings forms
lining of
esophagus, mouth, and vagina(‫)باطنيه‬.
Note more than two layer always Stratified Squamous Epithelium.
2- Transitional Epithelium (urinary EP)
Function: stretches and permits distension of urinary bladder
Location: Lines ureters, urinary bladder and part of urethra
WHY transitional, cause Different shape in the resting phase of the stretched
state.
3- Stratified Cuboidal Epithelium
Description: generally two layers of cube-shaped cells
Location: Forms largest ducts of sweat glands
Forms ducts of mammary glands and salivary glands
4- Stratified Columnar Epithelium
Description:several layers; basal cells usually cuboidal; superficial cells
elongated
Function: protection and secretion
Location:
Rare tissue type
Found in male urethra and vas deferens, largest ducts of salivary
glands, nasolpharynx
Note : in unique place The conjunctiva of the eye contains stratified
columnar epithelium,
If the plan doesn’t work, change the plane but never the goal…good
luck