Chapter 4: Integumentary System Chapter Objectives Upon completion of this chapter the participant will be able to: 1. 2. 3. 4. 5. 6. 7. 8. Identify and describe the structures of the skin. Discuss the functions of the skin. Locate the structures of the skin on a diagram. Analyze medical terms that are common to the skin Define medical terms that are common to the skin Spell medical terms that are common to the skin. Pronounce medical terms that are common to the skin. Successfully complete the review exercises at the end of the chapter. To give this chapter the title of “The Skin” is technically incorrect because the skin is only part of what will be discussed. The proper name that should be used is the “integumentary system”. This term comes from a Latin word which means “covering” and this system covers the body as a whole. Besides the skin we will also discuss the related structures of the hair, glands and nails. An extension of the skin “the breast” will also be discussed at this time. The breast, which is discussed in the next chapter, will also be referred to later in the course when we consider the female reproductive system. Anatomy and Physiology of the Skin The skin consists of a structure that has three distinct layers: Epidermis Dermis Subcutaneous layer Epidermis Consists of epithelial cells that also line the body cavities and the organs. Melanocytes are the cells in the skin that give it color. The reason for the color is the presence of a pigment called melanin. The more melanin you have the darker your skin will be. The skin is made tough, waterproof and resistant to infection by the presence of a protein called keratin. There are no blood vessels or nerves in this layer. Relies on the layers below it for nourishment. Outermost layer of the skin. Revised August 2003 -39- Hair shaft Pore Epidermis Dermis Sebaceous (oil) gland Subcutaneous Layer Hair follicle Sudoriferous (sweat) gland Vein Artery Nerve Dermis Layer of skin directly below the epidermis. Composed of blood and lymph vessels, nerve fibers, and the accessory organs of the skin. Blood vessels in this layer bring the nutrients to the skin. Blood vessels also help control the body temperature by dilating and allowing heat to escape when the body is hot and by constricting and preventing loss of heat when it is cold. Contains cells that allow it to be strong (fibroblasts), destroy bacteria (macrophages) and act against foreign bodies (mast cells and plasma cells) Subcutaneous Tissue Layer of connective tissue that is not really part of the skin. Revised August 2003 -40- Connects the dermis layer to the muscles and organs that are below. Contains fat that insulates the body parts below. Related Organs Hair Nails Glands (Sebaceous and Sweat) Hair Rod like fibers that are made up of dead protein cells filled with keratin. Grows from hair follicles. These are shafts or sacs that hold the hair fiber. The combining forms pil/o and pil/i. Color depends on the melanin that is present in the hair fiber. With aging there is a decrease in the amount of melanin we produce that explains why our hair turns gray. Nails Consist of epithelial cells that have been keratinized. The combining forms ungu/o and onych/o mean nails. Sebaceous Gland Glands that secrete an oily substance known as sebum. This substance lubricates the skin and because it has an acid property it discourages growth of bacteria. Located in the dermal layer and are closely associated with the hair follicles. The combining form for the sebum produced by these glands is seb/o. Sweat Gland Tiny coiled gland found on almost all body surfaces. Numerous in the palms of the hands and the soles of the feet. Ducts from these glands open onto the surface of the skin through pores. Sweat, which is 99% water, is secreted by these glands. This allows for the body to get rid of extra water and to cool as sweat is evaporated. The other term for sweat gland is “sudoriferous” gland. The combining form for sweat is hidr/o. Word Parts for the Integumentary System Roots albin/o adip/o, lip/o, steat/o Revised August 2003 white fat -41- bi/o cry/o cyan/o derm/o; dermat/o; cutane/o diaphor/e epitheli/o erythemat/o; erythr/o, erythem/o hidr/o hist/o, histi/o kerat/o; keratin/o leuk/o melan/o myc/o necr/o onych/o; ungu/o pil/o, pil/i py/o seb/o vascul/o life cold blue skin profuse sweating covering red, redness sweat tissue hard; hornlike white black fungus death nail hair pus sebum vessel Prefixes epi- upon, above, on Suffixes -derma oma -phagia -therapy Revised August 2003 skin tumor, mass eating treatment 42 Term Analysis and Definition Word Part Term Term Analysis Definition albin/o alb/o albinism albin = white -ism = condition Absence of pigment in the skin, hair and eyes. Appear very white. adip/o lip/o steat/o adipose adip = fat -ose = pertaining to Pertaining to fat lipoma -oma = tumor lip = fat Tumor or mass containing fat. bi/o skin biopsy bi = life -opsy = to view Removal of skin for microscopic examination cyan/o cyanotic cyan = blue -tic = pertaining to Pertaining to a bluish discoloration of the skin. derm/o dermat/o cutane/o dermatitis dermat = skin -itis = inflammation Inflammation of the skin. dermatology derm = skin -logy = study The study of the skin and its diseases. hypodermic hypo = under, below -ic = pertaining to derm = skin Pertaining to below the skin. subcutaneous Pertaining to under the skin. sub = under cutane = skin -ous = pertaining to diaphor/e diaphoresis diaphor = profuse sweating is = condition Condition where there is profuse sweating. epitheli/o epithelial epithel = covering -al = pertaining to Pertaining to the epithelium. epithelium epithel = covering -um = structure Structure made up of epithelial cells erythema erythr = red Red discoloration of the skin. erythematous erythemat = red -ous = pertaining to Pertaining to a redness of the skin. erythr/o erythemat/o erythem/o Revised August 2003 -43- Word Part Term Term Analysis anhidrosis -osis = abnormal condition a(n) = no, lack of hidr = sweat Abnormal condition where there is a lack of sweat. hyperhidrosis hyper = excessive Condition of excessive sweating. kerat/o keratin/o hyperkeratosis hyper = excessive -osis = abnormal condition kerat = hard, hornlike Excessive growth of the horny layer of the skin. leuk/o leukoderma leuk = white -derma = skin Lack of pigment in the skin that shows up as white patches. melan/o melanocyte melan = black -cyte = cell Cell that produces melanin. necr/o necrotic necr = death -tic = pertaining to Pertaining to death (of tissue) onych/o ungu/o onychomycosis onych = nail -osis = abnormal condition myc/o = fungus Fungal infection of the nail periungual peri- = around -al = pertaining to Pertaining to around the nail pil/o pil/i pilosebaceous pilo- = hair seb = sebum, oil -ous = pertaining to Pertaining to the hair follicles and the sebaceous glands py/o pyoderma py = pus -derma = skin Any pus-producing disease of the skin. pyogenic - genic = producing Pus producing. seb/o seborrhea seb = sebum -rrhea = flow, discharge Increased discharge of sebum from the sebaceous glands. vascul/o avascular a- = no, lack of vascul = vessel ar = pertaining to Pertaining to lack of blood vessels. hidr/o Revised August 2003 -44- Definition Word Part Term Term Analysis Definition epi- epidermis epi = upon, above dermis = dermis Above the dermis -oma adenoma aden = gland -oma = tumor Tumor of a gland. carcinoma carcin = cancerous -oma = tumor Malignant/cancerous tumor. melanoma melan = black -oma = tumor A malignant black mole or tumor (a tumor composed of melanin-pigmented cells) cryotherapy cry = cold therapy = treatment Treatment that involves use of cold as its basis. -therapy VOCABULARY WORDS: Acne an inflammatory condition of the sebaceous glands and hair follicles; Pimples Alopecia loss of hair; baldness Burn injury to tissue caused by heat, fire, lightening or radiation. Burns Are classified according to degree or depth of skin damage Carbuncle boil Cicatrix scar Comedo blackhead Decubitus ulcer a bed sore Exudate production of pus or serum Herpes simplex cold sore Urticaria hives Nevus mole Pruritus severe itching Tinea ringworm Revised August 2003 -45- Verruca wart ABBREVIATIONS: FUO Hx SLE Ung – – – - fever of unknown origin history Systemic Lupus Erythemoutosus ointment Revised August 2003