Transcript Document
Chapter 5 The Integumentary System and Body Membranes Objectives Classify, compare the structure of, and give examples of each type of body membrane. Describe the structure and function of the epidermis and dermis. List and briefly describe each accessory organ of the skin. List and discuss the three primary functions of the integumentary system. Question What are the four major types of membranes in the body? Membranes Epithelial membranes Mucous Membranes Serous membranes – Pleura – Pericardium – Peritoneum Connective Tissue Membranes CLASSIFICATION OF BODY MEMBRANES Epithelial membranes –Cutaneous membrane— the skin –More later!! Slide 5 Classification of Body Membranes Mucous membranes – Line body surfaces that open directly to the exterior – Produce mucus, a thick secretion that keeps the membranes soft and moist What are examples of mucous membranes? Serous Membranes Line the cavities that do not open to the outside world Double layered – Visceral – Parietal Serous fluid is in the cavity between them Synovial Membranes Connective tissue membranes – Do not contain epithelial components – Produce a lubricant called synovial fluid – Examples are the synovial membranes in the spaces between joints and in the lining of bursal sacs Slide 9 Disorders of Body Membranes Diseases – Pleurisy—inflammation of the serous membranes that line the chest cavity and cover the lungs – Peritonitis—inflammation of the serous membranes in the abdominal cavity that line the walls and cover the abdominal organs Integumentary System Integument Consists = covering of: – Skin – Accessory Organs: Hair Nails Glands The Skin largest organ of the body is the Question What are the functions of the skin? Functions of Skin Protects from injuries Acts as barrier and regulates what enters/leaves body. Regulates body temperature. Synthesizes, stores vitamins. Sensory functions Functions of the Skin Sense organ activity – Skin functions as an enormous sense organ – Receptors serve as receivers for the body, keeping it informed of changes in its environment—disorders of the skin (dermatoses) Functions of the Skin Protection—first line of defense – Against infection by microbes – Against ultraviolet rays from sun – Against harmful chemicals – Against cuts and tears – Skin grafts Structure of the Skin 3 main layers from superficial to deep 1) Epidermis Epiderm/o -is above skin structure “structure above the skin” a. Thin cellular membrane layer Structure of the Skin (cont’d) 2) Dermis Derm/o Skin “true skin” -is structure a. thick, contains connective tissue layer with collagen and elastic fibers, epithelial tissue, smooth muscle tissue, nervous tissue and blood Sensory Structures of Dermis Deep touch/pressure: Pacinian corpuscles Light touch/pressure: Meisner’s corpuscles Warm temperature: Free nerve endings Cold temperature: Free nerve endings Pain: Free nerve endings Structure of the Skin (cont’d) 3) Subcutaneous tissue Subcutane/o -us Below skin structure “structure below the skin” a. thick, fat-containing tissue Hypodermis (Subcutaneous) Recognize d by adipose tissue. Question What are some of the appendages of the skin? The Skin Appendages of the skin – Hair Soft hair of fetus and newborn called lanugo Hair growth requires epidermal tube-like structure called hair follicle Hair growth begins from hair papilla The Skin Appendages of the skin – Hair Hair root lies hidden in follicle; visible part of hair called shaft Alopecia hair loss Arrector pili—specialized smooth muscle that produces “goose pimples” and causes hair to stand up straight Slide 25 The Skin Nails – Produced by epidermal cells over terminal ends of fingers and toes – Visible part called nail body – Root lies in a groove and is hidden by cuticle – Crescent-shaped area nearest root called lunula – Nail bed may change color with change in blood flow Slide 28 The Skin Skin glands – Types Sweat or sudoriferous Sebaceous Skin The Skin glands – Sweat or sudoriferous glands Types – Eccrine sweat gland Most numerous, important, and widespread of the sweat gland Produce perspiration or sweat, which flows out through pores on skin surface Function throughout life and assist in body heat regulation The Skin Skin glands – Sweat or sudoriferous glands Types – Apocrine sweat gland Found primarily in axilla and around genitalia Secrete a thicker, milky secretion quite different from eccrine perspiration Breakdown of secretion by skin bacteria produces odor Skin glands The Skin – Sweat or sudoriferous glands Types – Sebaceous gland Secrete oil or sebum for hair and skin Level of secretion increases during adolescence Amount of secretion regulated by sex hormones Sebum in sebaceous gland ducts may darken to form a blackhead Acne vulgaris inflammation of sebaceous gland ducts Dermis Sweat gland Sebaceous gland Arrector pili muscle Blood vessels The Skin Appendages of the skin – Receptors Specialized nerve endings—make it possible for skin to act as a sense organ Meissner’s corpuscle—capable of detecting light touch Pacinian corpuscle—capable of detecting pressure Quick Quiz Which layer does not have a blood supply? Quick Quiz Which layer has the pigment cells? Quick Quiz What is that pigment called? Quick Quiz Which layer has the fatty tissue? Quick Quiz Which part of the epidermis is undergoing mitosis all the time? Case Study Katie is a 15-year-old girl who is very upset because of the pimples on her face. She cannot understand why her little sister Kimberly, who is 7, doesn’t have acne. Question What explanation can you give Katie concerning her skin? A. In several years Kimberly also will have acne. B. Acne is present most likely because she doesn’t wash her face. C. Acne is an allergic reaction to certain creams used on the face. D. Acne in adolescence is a result of overactive sebaceous glands. Question Katie is embarrassed because of the pimples on her face. Her mother has decided to seek medical attention. What sort of doctor will she probably see? A. dermatologist B. cosmetic specialist C. plastic surgeon D. pediatrician Question Which of the following statements about hair follicles is true? A. Arrector pili muscles are associated with them. B. Sudoriferous glands empty into them. C. They arise directly from the epidermis layer of skin. D. All of the above. Burns – Classification of burns First-degree (partial-thickness) burns—only the surface layers of epidermis involved Second-degree (partial-thickness) burns—involve the deep epidermal layers and always cause injury to the upper layers of the dermis Third-degree (full-thickness) burns— characterized by complete destruction of the epidermis and dermis and subcutaneous tissues. Slide 44 THE SKIN Burns – Treatment and recovery or survival depend on total area involved and severity or depth of the burn – Body surface area is estimated using the “rule of nines” (Figure 58) in adults Body is divided into 11 areas of 9% each Additional 1% located around genitals Slide 45 Burns First-degree (partial-thickness) burns—only surface layers of epidermis involved Second-degree (partial-thickness) burns—involve the deep epidermal layers and always cause injury to the upper layers of the dermis Burns Third-degree (full-thickness) burns (Figure 6-14) characterized by complete destruction of the epidermis, dermis, and subcutaneous tissue – May involve underlying muscle and bone (fourth-degree) – Lesion is insensitive to pain because of destruction of nerve endings immediately after injury—intense pain is soon experienced Burns Estimating body surface area using the “rule of nines” in adults – Body divided into 11 areas of 9% each – Additional 1% of body surface area around genitals Skin Lesions Elevated lesions—cast a shadow outside their edges – Papule—small, firm raised lesion – Plaque—large raised lesion – Vesicle—blister – Pustule—pus-filled lesion – Crust—scab – Wheal (hive)—raised, firm lesion with a light center Skin Lesions Flat lesions—do not cast a shadow – Macule—flat, discolored region Depressed lesions cast a shadow within their edges – Excoriation—missing epidermis, as in a scratch wound – Ulcer—craterlike lesion – Fissure—deep crack or break Skin Cancer Three common types – Squamous cell carcinoma—the most common type, characterized by hard, raised tumors – Basal cell carcinoma—characterized by papules with a central crater; rarely spreads – Melanoma—malignancy in a nevus (mole); the most serious type Skin Cancer The most important causative factor in common skin cancers is exposure to sunlight Kaposi sarcoma, characterized by purple lesions, is associated with AIDS and other immune deficiencies Skin Infections Impetigo—highly contagious staphylococcal infection – Tinea—fungal infection (mycosis) of the skin; several forms occur – Boils—furuncles; staphylococcal infection in hair follicles – Scabies—parasitic infection Vascular and Inflammatory Skin Disorders Decubitus ulcers (bedsores) develop when pressure slows down blood flow to local areas of the skin Urticaria or hives—red lesions caused by fluid loss from blood vessels Scleroderma—disorder of vessels and connective tissue characterized by hardening of the skin; two types: localized and systemic Vascular and Inflammatory Skin Disorders Psoriasis—chronic inflammatory condition accompanied by scaly plaques Eczema—common inflammatory condition characterized by papules, vesicles, and crusts; not a disease itself but a symptom of an underlying condition PSORIASIS Let’s Review! Which type of body membrane lines the digestive tract? A. Cutaneous membrane B. Tympanic membrane C. Serous membrane D.Synovial membrane E. Mucous membrane Slide 66 Which is the thickest part of the skin? A.Epidermis B.Dermis Slide 67 The gland that produces a “conditioning cream” for the hair and skin is the A. Eccrine sweat gland B. Apocrine sweat gland C. Sebaceous gland D.Mammary gland E. Ceruminous gland Slide 68 The skin plays important roles in maintaining a stable body temperature. A.True B.False What is the largest sensory organ of the body? A.Eye B.Ear C.Tongue D.Skin E.Nose Slide 70 What characterizes seconddegree burns? A. B. C. D. blisters swelling severe pain all of the above Questions? ????????????? ???????????? ?????????