1. Integumentary System I. Introduction A. Definition

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. II. Functions

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

5. III. Parts A. Epidermis

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

7. 2. Strata “Layers” a. Basal, Spinosum, Granulosum, Lucidium, & Corneum Figure 4.3Figure 4.4

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

9. 4. Epidermal Derivatives a. Hairi. Partsii. Types Figure 4.7

10. b. Naili. Parts Figure 4.9

11. c. Sweat Glandsi. Types

12. B. Dermis

13. 1. Definition 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

14. 2. Strata & Function

15. C. Hypodermis

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

18. IV. Problems A. Infections

20. B. Tumors

22. C. Wound Healing

24. D. Burns

25. Figure 4.11

26. Does effort equal success?