1. I. Tissue Groups Galena Park High School A&P Instructor: Terry E. Jones

2. A. Definition 1.A group of closely associated cells that perform related functions and are similar in structure.

3. B. Major Groups 1. Epithelia – surfaces 2. Connective – support 3. Muscular – movement 4. Nervous - control

4. II. Epithelia Tissue A. Epithelium: sheet of cells that covers a body surface or lines a body cavity; also form most of the body’s glands B. Roles: as interfaces and as boundaries

5. C. Functions: Protection Absorption Sensory reception Ion transport Secretion Filtration Formation of slippery surfaces for movement

6. D. Classification of Epithelia 1. According to thickness a. “simple” - one cell layer b.“stratified” – more than one layer of cells (which are named according to the shape of the cells in the apical layer)

7. 2. According to shape a. “squamous” – wider than tall b. Used for protection c. Found in areas where diffusion is important

8. Simple Squamous

9. 3. “cuboidal” – as tall as wide a. Found where there is exretion and absorption going on b. Large because of production of materials

10. Cuboidal

11. 3. “columnar” - taller than wide a. Secretion of mucous b. Found commonly lining the digestive system c. Some with cilia line the bronchiole tubes of the lungs

13. 4. “pseudostratified” – false layers a. appear to be in layers, but they are not b. All are in contact with the basal layer of cells c. They line the trachea

14. Pseudostratified

15. E. Formation of Glands 1. Epithelial cells form them 2. Production & secretion of needed substances

16. 3. Are aqueous (water-based) products 4. The protein product is made in rough ER,, packed into secretory granules by Golgi apparatus, released from the cell by exocytosis

17. F. Classification of Glands 1. Exocrine: external secretion onto body surfaces (skin) or into body cavities 2. Endocrine: secrete messenger molecules (hormones) which are carried by blood to target organs; “ductless” glands

18. Goblet Cell Makes Mucus

19. G. Examples of exocrine gland products 1. Sweat glands of skin 2. Oil glands of skin 3. Salivary glands of mouth 4. Liver (bile) 5. Pancreas (digestive enzymes) 6. Mammary glands (milk