This is simple presentation about the Epithelial tissue, which is one of the four tissues of human body and about the cell type, functions . . . etc.

1. Epithelial Tissue
Zoology Presentation
Supervisor: Adris Georgis Shilmon
27/02/2012

2. Prepared By:Prepared By:
Mahmoud Kh. Pirani
Bazhdr Hussein
Farhang Esmat
Shorsh Sh. Yaseen

3. Introduction
Cells are arranged in tissues that provide
specific functions for the body.
Cells of different tissues are structured
differently, which leads to differences in
their function.

4. 4 primary tissue types:
1. Epithelial tissue-covers surfaces, lines cavities, forms glands.
2. Connective tissue- supports and protects other tissues
3. Muscle tissue- causes movement.
4. Nervous tissue- receives and generates nerve impulses

5. Characteristics of Epithelial
Tissue
• All over the body, covers surfaces (like organs),
lines cavities, and forms glands.
• Lines body surfaces
• Anchored to a basement membrane
• Made of tightly packed cells
• Lack blood vessels
• Contain little extracellular material (matrix).
• Replaced frequently

6. Functions of Epithelial
Tissue
1. Protection
2. Secretion
3. Absorption
4. Excretion
5. Sensory reception

7. More epithelial characteristics:
• function is determined by the cell type and
number of cell layers.
• Anchored or supported by underlying
connective tissue:
– Basement membrane: separates the
epithelial and connective tissues.

8. 2 types of epithelial tissues
1. Covering and lining epithelia: covers surface of
body and organs, line all hollow body structures
2. Glandular epithelia: forms glands that produce
and secrete products needed by the body

9. Epithelial cell shapes:
• Squamous cells- the thinnest of the 4, have
a flattened nucleus
• Cuboidal cells- cubelike with a round
nucleus in the center of the cell
• Columnar cells- tall with an oval nucleus
close to the base of the cell
• Transitional cells- change shape (cuboidal
when tissue is relaxed, squamous when the
tissue is expanded)

10. EPITHELIAL TISSUE
TYPES
1. SIMPLE: Epithelial tissue with ONE cell
2. STRATIFIED: Epithleial with TWO OR
MORE

11. Three big Categories of Epi
general functions!
• Simple epi: provides a selective barrier for diffusion,
filtration, secretion, or absorption of selected substances
• Stratified epi: thicker, subject to wear and tear, forms
protective barrier
• Pseudostratified epi: one cell layer thick b/c all cells
touch the basement membrane, not all cells reach the
surface. Nuclei are at different levels giving the
appearance of different cell layers.

12. Three types of simple epi:
1. simple squamous
2. simple cuboidal
3. simple columnar

13. Four types of stratified epi:
1. Stratified squamous
2. Stratified cuboidal
3. Stratified columnar
4. Transitional

14. Two types of Pseudostratified epi:
Pseudostratified columnar
Pseudostratified ciliated