Anatomy of the Skin Information taken from: http://medicalcenter.osu.edu/patientcare/healthcare_services/skin_conditions/anatomy_skin/Pages/index.aspx Throughout the body, the skin's characteristics vary (i.e., thickness, color, texture). For instance, the head contains more hair follicles than anywhere else, while the soles of the feet contain none. In addition, the soles of the feet and the palms of the hands are much thicker. The skin is made up of the following layers, with each layer performing specific functions: Epidermis Dermis Subcutaneous fat layer (subcutis) Epidermis The epidermis is the thin outer layer of the skin which consists of the following three parts: Stratum corneum (horny layer) This layer consists of fully mature keratinocytes which contain fibrous proteins (keratins). The outermost layer is continuously shed. The stratum corneum prevents the entry of most foreign substances as well as the loss of fluid from the body. Keratinocytes (squamous cells) This layer, just beneath the stratum corneum, contains living keratinocytes (squamous cells), which mature and form the stratum corneum. Basal layer The basal layer is the deepest layer of the epidermis, containing basal cells. Basal cells continually divide, forming new keratinocytes, replacing the old ones that are shed from the skin's surface. The epidermis also contains melanocytes, which are cells that produce melanin (skin pigment). Dermis The dermis is the middle layer of the skin. The dermis contains the following: Blood vessels Lymph vessels Hair follicles Sweat glands Collagen bundles Fibroblasts Nerves The dermis is held together by a protein called collagen, made by fibroblasts. This layer gives skin flexibility and strength. It also contains pain and touch receptors. Subcutis (also known as the subcutane ous layer) The subcutis is the deepest layer of skin. The subcutis, consisting of a network of collagen and fat cells, helps conserve the body's heat and protects the body from injury by acting as a "shock absorber." MAKE YOUR OWN SKIN MODEL Use the picture above and the chart of skin layer characteristics as your guide. You can make your model as detailed or simple as you want, but at the very least you should include the 3 main skin layers (epidermis, dermis, and subcutaneous tissue) and a hair follicle. Choose the materials you want to represent your skin layers. you can use whatever reasoning makes the most sense to you to decide which product best represents each layer, for example do you want sugar as your Subcutaneous tissue because subcutaneous tissue is mostly comprised of collagen and fat cells? Do you want to use rice for the dermis because the shape reminds you of blood or lymph vessels? Do you want something with more color to represent the epidermis since that is where skin pigment is found? Choose materials that will help you remember later what is in each layer. Layer them in the cup, then add pasta or another material for your hair follicles. When you are done making your skin model, you can cover it with saran wrap and a rubber band to keep it from spilling.