1. Integumentary System I. Introduction A. Characteristics

2. 1. Skin, Cutaneous Membrane, or Integument 2. Largest organ 7% of body weight 3. Divisions = Epidermis, Dermis,& Hypodermis 4. Thick vs. Thin skin

3. Figure 5.1

4. II. Functions

5. 1. Protection from dehydration and mechanical damage 2. Sunscreen 3. Temperature Regulation 4. Waste Excretion 5. Produce Vitamin D 6. Sensory Reception

6. III. Parts A. Epidermis

7. 1. Characteristics a. Stratified squamous epithelium “Keratinized” b. Basic cell type called a keratinocyte c. All intercellular junction present d. Avascular and not innervated

8. 2. Strata or “Layers” a. Basal, Spinosum, Granulosum, Lucidium, & Corneum Figure 5.2

9. 3. Associated Cells a. Melanocytesb. Langerhans cellsc. Merkel cells

10. 4. Epidermal Derivatives a. Hairi. Partsii. Types & Function

11. b. Naili. Parts & Function

12. c. Sweat Glandsi. Types & Function

13. B. Dermis

14. 1. Characteristics a. Dense Irregular Connective Tissue b. Basic cell type = fibroblast (all others present) c. Collagen bundles thicken and increase in number with depth (Papillary versus Reticular) d. Highly vascularized and innervated

15. 2. Strata & Function Figure 5.3

16. C. Hypodermis

17. 1. Defining Characteristics a. Loose Connective Tissue b. Basic cell type = adipocyte (all others present) c. Fat layer (subcutaneous layer) d. Highly vascularized and innervated

18. 2. Function

19. IV. Problems A. Infections

21. B. Tumors

22. Figure 5.8

23. C. Wound Healing

25. Figure 4.12

26. D. Burns

27. Figure 5.9

28. Does effort equal success?