Unit 3 skillS Our first line of defence T he skin is the largest and heaviest organ of the body. It is the main barrier between the body and the outside world. It serves many important functions: it protects the body from external factors mechanical, biological and chemical; it regulates body temperature; it allows us to have the sensations of touch, heat, and cold; it maintains water and electrolyte balance; it produces vitamin D as a response to exposure to UVB radiation. The skin is made up of three layers, each with its own important 3 parts: epidermis, dermis, and hypodermis (or subcutaneous). Together, the epidermis and dermis form the cutaneous layer. The hypodermis is a subcutaneous layer connecting the skin to the underlying tissues. It also serves as a shock absorber and insulator for the organs. New skin cells are continuously forming at the bottom of the epidermis. When the cells are ready, they move toward the top of the epidermis to replace old cells. As they arrive, older top cells die and rise to the surface of the skin. Therefore, the cells covering and protecting our bodies are really dead skin cells which we will soon loose. Every minute of the day we lose about 30,000 to 40,000 dead skin cells off the surface of our skin. That s almost 4 kilograms of cells every year! Watch this video on How the skin works and complete the sentences. https://www.youtube.com/watch?v=nCzGflPoHa0 1. An adult s skin weighs about 2. The skin s top layer is the ............................................ pounds. ............................................. 3. ............................................ waterproofs and strengthens the skin. 4. ............................................ is the pigment which gives skin its colour. 5. The epidermis provides ............................................ sensation and protection against microorganisms. 6. Fat cells and adipose tissue are contained in the ............................................. 7. ............................................ is the layer which supports the skin and gives it strength and flexibility. 8. Sensory ............................................ in the dermis allow us to feel pressure, pain and temperature. 9. ............................................ vessels nourish the skin and eliminate wastes. 10. ............................................ glands are present all over the body, except in hand palms and feet soles. 4 PAIR WORK. Imagine you are going to a job interview. Refer to the text and the video and ask and answer possible questions about skin to prepare for the interview. What is the largest organ of the body? B: It is the skin, which is also the heaviest. A: Ideas: function of blood vessels, importance of skin oil, top and bottom layers of skin, function of melanin, function of dermis/hypodermis 28 balance: equilibrio exposure: esposizione insulator: isolante layer: strato to loose: perdere to maintain: mantenere to rise: salire shock absorber: ammortizzatore toward: verso underlying: sottostante