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.
A rhytid, (riâ²tid), is a wrinkle in the skin. The skin is composed of three layers: the epidermis, the dermis, and subcutaneous fat. The epidermis, the top layer of the skin, produces melanin, which gives the skin its color. It also protects the skin, with special cells known as keratinocytes, against environmental toxins.