1. Epithelial tissues

2. Epithelial functions 1) Protection: covers body and lines all body cavities; provides a protective shield for underlying tissues (e.g. epidermis) 2) Absorption: in some parts of the body it takes in certain materials (e.g. digestive tract) 3) Secretion: in some parts of the body epi. tissue is specialized to secrete certain products E.g. small intestine: some cells are specialized to secrete mucus 4) Excretion: in the kidney cells rid the body of materials 5) Surface transport: cilia on cells in the lungs move mucus and particles up and out 6) Sensory functions: Ex. taste buds in the mouth

3. Cell shapes 1) squamous: square cells that are thin and flat 2) cuboidal: small cubes in cross section 3) columnar: tiny columns

4. Layers 1) simple: one layer of cells 2) stratified: cells arranged in two or more layers 3) pseudostratified: falsely appear to be layered

5. Epithelial tissues Cover all body surfaces, and body organs Epithelial tissues are avascular ET have a free surface, exposed to the outside of the structure Under side have a basement membrane, always near connective tissue, connective tissues are very vascular Cancers of epithelial tissues are called carcinomas

6. Simple Squamous Epithelium Location: Alveoli of lungs, walls of capillaries, and linings of blood vessels Function: Diffusion, filtration, and osmosis

7. Simple Squamous 1000X

8. Simple Squamous

9. Simple squamous 400X

10. Simple Cuboidal epithelium Location: surface of ovaries, linings of kidney tubules, and various other glands Function:Secretion and absorption

11. Simple Cuboidal 400X

12. More simple cuboidal 400X

13. Simple cuboidal 400X

14. Simple Columnar Epithelium Location: lining of digestive tract, lining of uterus Function:Protection, secretion, and absorption Goblet cells often present- Secrete mucus

15. Simple Columnar 400x

16. Simple columnar with Goblet cells 400x

17. Psuedostratified Columnar Epithelium Location: Lining of respiratory tract, and lining of various tubes of reproductive tract. Function: Protection, secretion, and movement of sex cells

18. Pseudostratified Columnar 400X

20. Trachea 400X

21. Stratified Squamous Epithelium Location:Outer layers of skin, linings of mouth cavity, and anal canal Function: Protection Keratinazation- cells become filled with Keratin Keratin- protein found in skin that waterproofs skin

22. Stratified squamous 400X

23. Stratified squamous 400x

24. Stratified Squamous 400X

25. Transitional Epithelium Location: Lining of urinary bladder, passageways of urinary tract Function: Distensibility and protection Distensibility- ability to change shape

26. Transitional