1. Epithelial tissue part 1
Histology
Epithelial tissue part 1
05/06/1438
lecturer Farah E. Alrawi

2. lecturer Farah E. Alrawi
05/06/1438
lecturer Farah E. Alrawi

3. The main characteristics of basic types of tissue are:
Function
Extracellular matrix
cells
Tissue
Transmissionof nerve impulses
Very small amount
Elongated cells with extremely fine processes
Nervous
Lining of surface or body cavities;
glandular secretion
Small amount
Aggregated polyhedral cells
epithelial
movements
Moderate amount
Elongated contractile cells
Muscle
Support and protection of tissues/organs
Abundant amount
Several types of fixed and wandering cells
connective
05/06/1438
lecturer Farah E. Alrawi

4. lecturer Farah E. Alrawi
Epithelial Tissue
Epithelia are cellular sheets that line the cavities of organs and cover the body surface.
05/06/1438
lecturer Farah E. Alrawi

5. The principal functions of epithelial tissues include the following:
Protection
Sensation
Secretion
Absorption
Cellular transport
Contractility
05/06/1438
lecturer Farah E. Alrawi

6. Characteristics features of epithelial tissue
05/06/1438
lecturer Farah E. Alrawi

7. Polarity of epithelia
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lecturer Farah E. Alrawi

8. Junctional complexes of epithelial cells
05/06/1438
lecturer Farah E. Alrawi

9. lecturer Farah E. Alrawi
05/06/1438
lecturer Farah E. Alrawi

10. 05/06/1438
lecturer Farah E. Alrawi

11. Basal laminae and basement membranes
All epithelial cells have at their basal surface a sheet like extracellular structure called the basal lamina, separating them from the underlying connective tissue.
where are formed from an electron-dense layer composed of:
1. lamina lucidae: which appear to be transparent.
2. lamina densa: a delicate network of fine fibrils.
05/06/1438
lecturer Farah E. Alrawi

12. Basement membrane
05/06/1438
lecturer Farah E. Alrawi

13. Functions of basal lamina
It is considered as a molecular filter and as a flexible, firm support for the overlying epithelium.
Provide a selective barrier between connective tissue and other cells.
The presence of the basal lamina around a muscle cell is necessary for the establishment of new neuromuscular junctions.
The ability to influence cell polarity.
Regulate cell proliferation and differentiation by binding with growth factors.
Influence cell metabolism
05/06/1438
lecturer Farah E. Alrawi

14. 05/06/1438
lecturer Farah E. Alrawi

15. Covering epithelium/Simple epithelia
05/06/1438
lecturer Farah E. Alrawi

16. Covering epithelium/Simple epi.
05/06/1438
lecturer Farah E. Alrawi

17. Covering epi.\Stratified epithelium:
05/06/1438
lecturer Farah E. Alrawi

18. Covering epi.\Stratified epithelium:
05/06/1438
lecturer Farah E. Alrawi

19. Proliferation and regeneration of epithelia
05/06/1438
lecturer Farah E. Alrawi

20. Thank you
05/06/1438
lecturer Farah E. Alrawi