1. MUSCLE CONTRACTION GET OUT YOUR NOTEBOOK

2. Grip the close-pin and squeeze it together as many times as possible in one minute (always keep the same grip) Record number and get ready for a second trial Record number and get ready for a third trial Record- explain how it felt and how your numbers changed over time What muscle is being used for this experiment

3. SKIN (INTUGUMENTARY SYSTEM) NOTES

5. GENERAL INFORMATION The skin is only a few millimeters thick yet is by far the largest organ in the body. The average person’s skin weighs 10 pounds and has a surface area of almost 20 square feet. Skin forms the body’s outer covering and forms a barrier to protect the body from chemicals, disease, UV light, and physical damage. Hair and nails extend from the skin to reinforce the skin and protect it from the environment...innerbody.com

6. THE INTEGUMENTARY SYSTEM - WHAT IS IT? Integument (skin) Hair Nails Glands (sweat and oil) A fatty layer (hypodermis) lies deep to it Two distinct regions Epidermis Dermis

7. LAYERS

8. WHAT ARE THE FUNCTIONS OF THE INTEGUMENTARY SYSTEM? 1. Protection against viruses, bacteria, dirt and water loss 2. Temperature Regulation 3. Produce Vitamin D 4. Excretion of wastes 5. Sensory organ (nerve endings)

9. WHAT ARE THE MAIN LAYERS OF THE INTEGUMENTARY SYSTEM? 2 (3) main layers: Epidermis “over” the dermis Thin layer of epithelial cells Dermis “skin” Thicker, tough layer of dense irregular connective tissue and other components Hypodermis “ below the skin” Technically NOT part of the skin, varies in thickness depending in part on the amount of adipose present

11. CARE OF THE SKIN Lotions- keep moisture in Sunscreen- keeps ultraviolet rays from penetrating and causing mutations (cancer) to form Cleaning- keeps pores free from build up of dirt and oils that can block the release of wastes and cause blemishes Healthy diet- provides nutrients needed to repair damage