Unit 5: Hemoglobin Testing 6 Original: October 1999 Revision: September 2010 Before you learn about how to use the HemoCue machine and take blood from clients, you need to learn about anemia and the causes of anemia.
Skin has three layers: 1  The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone. 2  The dermis, beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands. 3  The deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue.
The fourth layer in the epidermis is called the stratum lucidum, or the clear layer. This layer is present only in the fingertips, palms, and soles of the feet. It is 3-5 layers of extremely flattened cells. The fifth layer, or horny layer, is called the stratum corneum. This is the top, outermost layer of the epidermis and is 25-30 layers of flattened, dead keratinocytes. This layer is the real protective layer of the skin.