1. Basic Tissue Types Epithelium The Anatomy Lecture of Dr. Nicolaes Tulp - Rembrandt (1632) The Cadaver belongs to Aris Kindt 1/16/1632 Hanged for burglary

2. Basic Tissue Types There are four basic tissue types –Epithelium –Muscle –Bone –Connective Tissue Today we will discuss the First type – Epithelium

3. Epithelial tissue consists of cells arranged in continuous sheets in either single or multiple layers. They are closely packed with little intracellular space

4. Epithelial Cells Provide an excellent protective barrier Separate and isolate substances within the body They have a very high rate of cell division, due to high rate of physical stress and injury

5. Epithelial cells have specialized areas Apical (free) surface - Faces the body surface, lines a body cavity or the open space of an internal organ

6. Epithelial cells have specialized areas Apical (free) surface - Faces the body surface, lines a body cavity or the open space of an internal organ Lateral surface - faces adjacent cells on either side and may contain gap junctions for communication

7. Gap Junction - used for communication

8. Epithelial cells have specialized areas Apical (free) surface - Faces the body surface, lines a body cavity or the open space of an internal organ Lateral surface - faces adjacent cells on either side and may contain gap junctions for communication Basal surface - opposite the apical end and adheres to the matrix

10. Epithelial tissue has a nerve supply but has no blood vessels going to it (avascular) these cells get all their nutrition through the process of diffusion

11. Epithelial cells are classified according to two characteristics: Layers and Shapes

12. Layer Classification Simple Epithelium - Single layer that functions in diffusion, filtration, secretion and absorption - These cells are found in the blood vessels, heart, air sacs and parts of the kidney

13. Simple Epithelium

14. Layer Classification Pseudostratified Epithelium - Multiple layers of cells with nuclei appearing at different levels. Not all cells reach the apical end, however all cells reach the matrix. These cell are found in the respiratory tract, glands and the male reproductive tract

15. Pseudostratified Epithelium Cilia

16. Layer Classification Stratified Epithelium - Contains two or more layers of cells, found in locations with considerable wear and tear. These cells are found in the tongue, esophagus, mouth and vagina

18. Stratified Squamous Epithelium

20. Shape Classification Squamous Epithelium - Flat cells, arranged like tiles, very thin and allow for the rapid movement of substances These cells may or may not have a keratinized surface (keratin protein) depending on location

21. Keratinized Stratified Squamous Epithelium Keratin

22. Shape Classification Cuboidal Epithelium - These cells are as tall as they are wide. They are shaped like cubes or hexagons. These cells often have microvilli on their apical surface

23. Cuboidal Epithelium

24. Shape Classification Columnar Epithelium - These cells are much taller than they are wide. Many of these cells have cilia, they are specialized for secretion and absorption

25. Columnar Epithelium

26. Shape Classification Transitional Epithelium - These cells can change shape cuboidal to flat (simple) as such organs as the bladder distend with urine

27. Transitional Epithelium Cuboidal Squamous

28. Practice Quiz The Anatomist - Gabriel Von Max (1869)

29. What Am I?