1. EpitheliumEpithelium Michael Hall PhD University of California Los Angeles University of California Los Angeles

3. Features common to all epithelia 1.The cells are closely packed together 2.The cells are polarized 3.The apex always faces an open space 4.The base always sits on a basement membrane

4. Epithelial cells are closely packed

5. Free Surface Lamina propria Epithelial cells always have a free surface and sit on a basement membrane

6. Epithelium Basementmembrane Epithelium Basementmembrane Note that both of the epithelia face a free surface

7. Types of Epithelium Simple One cell layer Stratified More than one cell layer

8. Types of Epithelium 1.Simple squamous 2.Simple cuboidal 3.Simple columnar 4.Stratified squamous 5.Stratified cuboidal 6.Stratified columnar 7.Pseudostratified 8.Transitional

9. Simple squamous epithelium Basement membrane Connective tissue Free space

10. Simple squamous epithelium (endothelium) lining an arteriole endothelium

11. Simple cuboidal epithelium (kidney) Free surface Basement membranes

12. ss q sc u sc u* Simple epithelia in kidney medulla

13. Simple columnar epithelium (duodenum)

14. Stratified Squamous Epithelium (cornea) bm ct free surface

15. Stratified Squamous Epithelium free surface basement membrane squamous cells

16. Stratified Cuboidal Epithelium Duct of sweat gland Basement membrane Connective tissue

17. Stratified Columnar Epithelium (urethra) lp bm Columnar cells

18. PseudostratifiedEpithelium

19. Basement Membrane Pseudostratified Columnar Epithelium (duodenum) Basal cells

20. Transitional Epithelium (Urinary system)

21. TransitionalEpithelium (relaxed -top layer of cells is cuboidal) TransitionalEpithelium (stretched-top layer of cells is squamous) basement membrane

22. Mesothelium endothelium Endothelium Mesothelium is the name given to the simple squamous epithelium that lines the closed cavities of the body

24. Basement membranes

25. Simple squamous epithelium Basement membrane Connective tissue

26. Basement Membrane of epithelium

27. Molecular structure of extracellular matrix forming the basement membrane forming the basement membrane Inside of cell

28. Junctional Complexes

29. ‘Terminal Bars’ between epithelial cells

30. Epithelial Junctional Complex Z. occludens Z. adherens Desmosome Cell 1 Cell 2

31. Components of the Epithelial Junctional Complex 1.Z. occludens 2.Z. adherens 3.Macula adherens (desmosome) 4. Gap junction 5. Hemidesmosome 1 2 3 4 5

32. Generalized Structure of a Junctional Complex Cell 1 Cell 2

33. < 1,500 Da > 1,500 Da Connexon 2 Connexon 1 Gap Junction

34. Surface Specializations of Epithelial Cells

37. Myosin Actin Spectrin Structure of a microvillus Fimbrin Villin

38. Stereocilia in the Epididymis Stereocilia

39. Cilia in the Respiratory Mucosa Cilia

40. cilia microvilli

42. Basement membrane Mucosa Components of a Mucosa

44. The End Whoopee !!