1. WARM UP “Tears are the safety valve of the heart when too much pressure is laid upon it.” –Albert Smith 1.Do you agree with this? Why? 2. How does this apply to this unit?

2. Integumentary System

3. Overview Integument –Latin for “to cover” –Tough, flexible barrier –Skin

4. Skin Basics Weighs 4 kg. (9 lbs.) 15 sq. ft. in area

5. Layers of Skin Epidermis –Thin epithelial tissue –Dead cells Dermis –Many living structures –Connective tissue Hypodermis –Mostly fat

6. Structures of Skin Sweat glands –99% water Oil glands Hair –Follicles (root) –Live roots, dead tips Sensory receptors Blood vessels

7. Skin Functions Flexibility –Softness from oils –Dermal c.t. Blocks UV rays –Pigments in epidermis Kills and blocks bacteria, holds moisture –Stratified squamous –Oil glands

8. Skin Functions Repairs injuries –Cell replacement Makes Vitamin D for calcium absorption –Pigment Temperature regulation –Hairs and fat –Sweat glands Senses –Receptors

9. WRAP UP List 4 or 5 ways the structure of the skin allows it to help control your body’s temperature.

10. WARM UP 1.List 4 functions of skin. 2.Identify the structure or structures responsible for each function listed in #1.

11. WRAP UP Describe why stratified squamous epithelium is effective as a part of the integumentary system (and its functions).