1. Warmup 1/12/16 How does sweating work? Explain as best as you can Objective Tonight’s Homework To define some additional aspects to skin pp 513: 5, 6, 7, finish integumentary page

2. Notes on Integumentary System II Hair Hair follicles are located on almost the entire body. The root of the hair sits in a follicle and grows upward out of the skin. Hair is made of dead cells. As new cells are added to the base, it pushes the others up. Scalp hair grows at a rate of about ½ in per month. Stratum corneum

3. Notes on Integumentary System II Hair Attached to hair is an erector muscle. This muscle pulls tight when afraid or cold, causing goosebumps. Stratum corneum

4. Notes on Integumentary System II Oil Glands Connected to every hair follicle is an oil gland. This keeps the hair and skin soft. The amount of oil your skin produces is inherited. Without oil, the skin dries up and cracks. Stratum corneum

5. Notes on Integumentary System II Sweat Glands Last are the sweat glands. Every square inch of your skin contains about 80 of these. These push out a mixture of (mostly) water and salt to help cool the body down when overheated. On a hot day, a person can sweat out as much as 2 gallons. Stratum corneum

6. Notes on Integumentary System II Sensory Receptors There are many other things embedded in skin. Notably, there are sensory receptors – specialized nerve cell clusters designed to sense pressure, temperature, pain, etc. We’re going to go into more detail on these when we get to the nervous system.

7. How Much Skin? We’ve mostly covered all we need to about skin by this point. Let’s wrap up our discussion with an activity. Your job for the rest of class is to determine as accurately as possible how much skin you have. There are rulers up front. See if you can get your answer in square meters or square centimeters.

8. Exit Question What causes acne? a) A blockage of the sweat glands b) A blockage of the hair follicle c) A blockage of the oil glands d) A blockage of the nerve endings e) A blockage of the erector muscle connection f) None of the above