Classification of epithelium

1. Classification of epithelium
Amjad al-bleahid

2. Classification of epithelium

3. According to their
structure and function :
Covering ( or lining )
epithelia . Glandular epithelia .

4. Covering epithelia

5. Classificationofliningepitheliaaccordingtothe
numberofcelllayers :
• Simple epithelia
• One layer.
• Stratified epithelia
• More than one .

6. Based on cell shape :
Stratified epitheliaSimple epithelia
Squamous kertinized.Squamous .
Squamous non kertinized.cuboidal
cuboidalColumnar
Columnar.Pseudostratified
Transitional.

7. Glandular epithelia

8. Classified according to
various criteria
1- Number of secretory cells .
B- Multicellular glands .A- Unicellular glands .

9. Presence or absence of duct :
• Exocrine glands
• Duct .
• Endocrine glands
• ductless .

10. Exocrine glands have :
• Ducts : which
transport the
secretion out of the
gland .
• Secretory portion :
which contains the
cells specialized for
secretion .

11. Ducts
• A- ducts can be simple
( unbranched )
• B- and can be compound
( with tow or more
branches )

12. Secretory portions can be
A-Tubular ( short or long and
coiled )
B- Acinar ( round or globular )
# Either type of secretory portion may be
branched .
# Compound glands can have tubular , acinar ,
or tubuloacinar secretory portions.

13. Exocrineglandsalsoclassifiedfunctionallyaccording
tothewaythesecretoryproductsleavethecell:
• A- Merocrine secretion .
• B- Holocrine secretion .
• C- Apocrine secretion .