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.
Two distinct layers occur in the skin: the dermis and epidermis. The basic cell type of the epidermis is the keratinocyte, which contain keratin, a fibrous protein. Basal cells are the innermost layer of the epidermis. Melanocytes produce the pigment melanin, and are also in the inner layer of the epidermis. The dermis is a connective tissue layer under the epidermis, and contains nerve endings, sensory receptors, capillaries, and elastic fibers. The integumentary system has multiple roles in homeostasis, including protection, temperature regulation, sensory reception, biochemical synthesis, and absorption. All body systems work in an interconnected manner to maintain the internal conditions essential to the function of the body.