1. Class #1

2. Functions of the Skin Touch your fingertips, your arm, and your face. The soft tissue you feel is the largest organ of your body, your skin.

3. Functions of the Skin Your skin is part of the integumentary system, which includes all the external coverings of the body, including the skin, nails, and hair.

4. Functions of the Skin Most parts of the integumentary system are shown in Figure 15. Like bones and muscles, skin serves many different functions in your body.

5. Protection When you look at yourself in a mirror, you cannot see the bones, muscles, or other parts of your skeletal and muscular systems. Instead you see your skin.

6. Protection Skin covers your bones and muscles and protects them from the external environment.

7. Protection It keeps your body from drying out in sunlight and wind.

8. Protection Skin also protects the cells and tissues under the skin from damage.

9. Protection Skin is the first line of defense against dirt, bacteria, viruses, and other substances that might enter your body.

10. Sensory Response Close your eyes, and feel the surface of your desk and the objects on top. Even with your eyes closed, you can tell the difference between the desk, a book, paper, and pencils.

11. Sensory Response This is because your skin has special cells called sensory receptors that detect texture.

12. Sensory Response Sensory receptors also detect temperature and sense pain.

13. Sensory Response The more sensory receptors there are in an area of skin, the more sensitive it is.

15. Temperature Regulation Skin helps control body temperature.

16. Temperature Regulation When you exercise, sweat comes from tiny holes, or pores, on the skin’s surface, as shown in Figure 16.

17. Temperature Regulation Sweating is one way skin lowers your body temperature. As sweat evaporates, excess thermal energy leaves the body and the skin cools.

18. Temperature Regulation Another way that skin lowers body temperature is by releasing thermal energy from blood vessels.

19. Temperature Regulation Has your face ever turned red while exercising? The girl in Figure 16 has a red face because the blood vessels near the skin’s surface dilated or enlarged. This increases the surface area of the blood vessels and releases more thermal energy.

20. Production of Vitamin D If your skin is exposed to sunlight, it can make vitamin D.

21. Production of Vitamin D Your body needs vitamin D to help it absorb calcium and phosphorous and to promote the growth of bones.

22. Production of Vitamin D Your skin is not the only source of vitamin D. Vitamin D is usually added to milk and is found naturally in certain types of fish.

23. Homework Skin:____________________ Soft Tissue:________________ Integumentary System:______ _________________________ Protection:________________ External Environment:_______ Drying Out:_______________ The first line of defense:_____ _________________________ Sensory Response:__________ Sensory Receptors:_________ Pain:_____________________ Pores:____________________ Translate the words into Chinese and then send me a WeChat message saying the words in English Name:____________ Sweat:____________________ Temperature Regulation:______ Blood Vessels:_______________ Dilated:_____________________ Vitamin D:__________________ Found Naturally:_____________ Your skin is the largest organ of your body.__________________ The integumentary system includes your skin, hair, and nails:_______________________ Skin covers your bones and muscles and protects them from the external environment:____ ___________________________

24. Fill in the blanks with the correct response. 1. Your ______ is the largest organ of your body. 2. Skin helps keep your body from _____ in sunlight. 3. Skin also ________ the cells and tissue under the skin from damage. 4. Sensory receptors detect temperature and sense _____. 5. The more _____________ there are in an area of skin, the more sensitive it is. 6. __________ is one way skin lowers your body temperature. 7. Skin lowers body temperature by releasing ______________. 8. Your body needs __________ to promote the growth of bones. Name: ____________ Drying out Sensory receptors Pain Skin Vitamin D ProtectsSweating Thermal Energy

25. Dictation Wordlist Lucy: Integumentary System Michael: Protection Mi Xue: External Environment Stephanie: Blood Vessels Simon: Sensory Receptor Eric: Organ Alice: Temperature Regulation Spring: Vitamin D Judy: Dilated Candy: Sensory Response Ling Ling: Skin Michael 2: Sweat Phoebe: Pores