Medical brain notes 41

  A lthough massage and other complementary ther-apies affect many systems, the organ system or struc-ture that is physically handled by the therapist is the integumentary system. Therapists use their sense of touch to assess their clients’ temperature, texture, and tension of soft tissue. The client perceives the manipulation by the therapist through the skin and  complex mechanical, physiologic, and psychological responses are produced in the deeper structures. A thorough knowledge of structure and function will help therapists treat clients more effectively. For ex-ample, some areas of the skin are more sensitive to touch than others and less pressure is sufficient. The type of technique used and the rate, vigor, and rhythm determine the effect on the client. Because client satisfaction largely relies on the sensations evoked, knowledge of how the brain perceives sensa-tion gains importance. Heat and cold may be used for therapy and questions, such as what effect they have ...

  Functions of the Skin The skin has many functions. It protects the underlying organs and tissues from abrasion, irradiation from sunlight, and attack by pathogens and other harmful agents. Salt, water, and certain organic wastes are lost through sweat and, thus, the skin has excretory functions. The skin plays an important role in maintenance of body temperature. It prevents loss of heat when the atmosphere is cold and facilitates loss of heat when the body gets hot. The skin detects changes in the surrounding environment by its ability to sense touch, pressure, pain, and temperature and relays this information to the central nervous system. The skin participates in the synthesis of vitamin D, which plays an important role in calcium metabolism. Its vast surface area helps store nutrients. The skin also serves as a reservoir of blood, as the volume of blood flowing in its extensive network of blood vessels can be altered according to systemic needs. Diseases of the body are often...

  Structure of the Skin The integument consists of the cutaneous membrane, or skin, and the accessory structures, such as hair, nails, glands, muscles, and nerves (see Figure 2.1). The skin covers an area of approximately 1.5–2 m 2  (59–78.7 sq in) and is responsible for about 16% of body weight. The superficial part of the skin is the  epithelium,  or  epidermis.  Deep to the epithelium is a layer of con-nective tissue, the  dermis,  in which the glands, hair, and nails are located. Deep to the dermis is the  subcu-taneous layer,  or hypodermis,  which consists of looseconnective tissue and adipose tissue. This layer sepa-rates the skin from the underlying muscle, bone, and other structures. THE EPIDERMIS The epidermis (see Figures 2.2 and 2.3) is the most superficial layer of the skin and is composed of strat-ified squamous epithelium. The epidermis is sepa-rated from the dermis—the deeper layer—by the basement membrane. Not havin...

  THE EPIDERMIS The epidermis (see Figures 2.2 and 2.3) is the most superficial layer of the skin and is composed of strat-ified squamous epithelium. The epidermis is sepa-rated from the dermis—the deeper layer—by the basement membrane. Not having a direct blood sup-ply, the epidermis relies on nutrients in the intersti-tial fluid that have diffused from the capillaries lo-cated in the dermis. There are four types of skin cells: ·             keratinocytes   ·             melanocytes   ·             Merkel cells   ·             Langerhans cells  (Figure 2.2).   Keratinocytes make up 90% of the epidermis; they lie in many distinct layers and produce a tough fi-brous protein called  keratin.  Keratin helps protect the skin from heat,...