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Chapter 20 - The integumentary system. After studying this chapter you will be able to: List the functions of skin, explain the role of skin in regulating body temperature, describe the layers of skin and the characteristics of each layer, explain the factors that affect skin color, identify and describe common skin lesions,...
CHAPTER 20 The Integumentary System © 2011 The McGraw-Hill Companies, Inc All rights reserved 202 Learning Outcomes 20.1 List the functions of skin 20.2 Explain the role of skin in regulating body temperature 20.3 Describe the layers of skin and the characteristics of each layer 20.4 Explain the factors that affect skin color 20.5 Identify and describe common skin lesions © 2011 The McGraw-Hill Companies, Inc All rights reserved 203 Learning Outcomes (cont.) 20.6 List the accessory organs of skin and describe their structures and functions 20.7 Explain the process of skin healing, including scar production 20.8 Describe the effects of aging on skin 20.9 List the different types of burns and describe their appearances and treatments © 2011 The McGraw-Hill Companies, Inc All rights reserved 204 Learning Outcomes (cont.) 20.10 Describe the causes, signs and symptoms, and treatments of various types of skin cancer 20.11 Describe the causes, signs and symptoms, and treatments of common skin disorders 20.12 Explain the ABCDE rule and its use in evaluating melanoma 20.13 Using the acronym CAUTION, list the seven warning signs of cancer © 2011 The McGraw-Hill Companies, Inc All rights reserved 205 Introduction • Integumentary system consists of skin and its accessory organs • Accessory organs: – Hair follicles – Nails – Skin glands Skin is the body’s outer covering and its largest organ © 2011 The McGraw-Hill Companies, Inc All rights reserved 206 Functions of the Integumentary System • Protection – First line of defense against • • Bacteria Viruses – Protects underlying structures from • • Ultraviolet (UV) radiation Dehydration © 2011 The McGraw-Hill Companies, Inc All rights reserved Functions of the Integumentary System 207 (cont.) • Body temperature regulation – If too hot • • Dermal blood vessels dilate Vessels carry more blood to surface so heat can escape – If too cold • • Dermal blood vessels constrict Prevents heat from escaping © 2011 The McGraw-Hill Companies, Inc All rights reserved Functions of the Integumentary System 208 (cont.) • Vitamin D production – Needed for calcium absorption • Sensation – Sensory receptors • Excretion – Small amounts of waste products are lost through perspiration © 2011 The McGraw-Hill Companies, Inc All rights reserved 209 Apply Your Knowledge What are the functions of the integumentary system? ANSWER: The functions of the integumentary system are protection, regulation of body temperature, vitamin D production, sensation, and excretion Super! © 2011 The McGraw-Hill Companies, Inc All rights reserved 2010 Structure of Skin • Epidermis • Dermis • Hypodermis or subcutaneous layer Back © 2011 The McGraw-Hill Companies, Inc All rights reserved 2043 Malignant Melanoma • Signs and Symptoms – From melanocytes – Appear on trunk, head, neck of men – Appear on arms and legs of women – Itches or bleeds • Treatment – Surgery and biopsy – Removal of lymph nodes – Chemotherapy and radiation therapy – Immunotherapy © 2011 The McGraw-Hill Companies, Inc All rights reserved 2044 Stages of Melanoma Stage Only found in epidermis Stage I Spread to epidermis and dermis (1 to mm thick) Stage II to mm thick plus ulceration Stage III Spread to one or more lymph nodes Stage IV Spread to other body organs or lymph nodes far from original melanoma © 2011 The McGraw-Hill Companies, Inc All rights reserved 2045 ABCDE Rule A Asymmetry – a mole should not become asymmetrical It should look equal in size from side to side B C D Border – a mole should not have irregular borders and edges should not blur into normal tissue E Evolving – a mole that has been changing in size, color and appearance, or growing in an area of previously normal skin Color – a mole should not change or become mixture of colors It should have even coloring Diameter – a mole should not grow larger than the diameter of a pencil eraser (6 mm.) © 2011 The McGraw-Hill Companies, Inc All rights reserved 2046 24-46 Cancer Warning Signs C– A– U– T– I – O– N– Change in bowel or bladder habits A sore that will not heal Unusual bleeding or discharge Thickening or lump Indigestion or difficulty swallowing Obvious change in wart or mole Nagging cough or hoarseness © 2011 The McGraw-Hill Companies, Inc All rights reserved 2047 Apply Your Knowledge True or False: ANSWER: F Basal cell carcinoma is the most aggressive form of skin _ cancer and can form anywhere Melanomas are more aggressive T _ Squamous cell carcinoma is more likely to spread to T surrounding tissues _ Lesions of melanoma appear on trunk, head, neck of F men and on arms and legs of women are irregular _ The borders Borders of skin cancers are usually regular T _ Basal cell carcinoma progresses slowly and rarely spreads to other body parts © 2011 The McGraw-Hill Companies, Inc All rights reserved 2048 Common Skin Disorders Alopecia • – Results in hair loss Dermatitis Cellulitis • – Inflammation of connective tissue in skin Eczema Inflammation of skin or a rash Chronic dermatitis Folliculitis Inflammation of hair follicles © 2011 The McGraw-Hill Companies, Inc All rights reserved 2049 Common Skin Disorders • Herpes simplex • – Type – cold sores – Type – genital • Herpes zoster – Shingles • Impetigo (cont.) Pediculosis – Head lice – Body lice – Pubic lice • Psoriasis – Inherited autoimmune disorder – Oozing skin lesions that eventually crust over © 2011 The McGraw-Hill Companies, Inc All rights reserved 2050 Common Skin Disorders • Ringworm – Tinea corporis – Tinea capitis – Tinea pedis • Rosacea – Dilation of small facial blood vessels (cont.) • Scabies – Contagious skin condition caused by mites • Warts – Harmless growths caused by a virus © 2011 The McGraw-Hill Companies, Inc All rights reserved 2051 Apply Your Knowledge Match the following: ANSWER: C Alopecia _ A Dilation of small facial blood vessels E Folliculitis _ B Inherited autoimmune disorder F Impetigo _ C Hair loss B Psoriasis _ D Growths caused by a virus A Rosacea _ E Inflammation of hair follicles D Warts _ F Oozing skin lesions Right! © 2011 The McGraw-Hill Companies, Inc All rights reserved 2052 In Summary 20.1 The functions of skin include protection, body temperature regulation, vitamin D production, sensation, and excretion 20.2 When the body is warm, the dermal blood vessels dilate, allowing heat to escape and cool the body When the body is cool, the same vessels constrict, preventing the heat carried by blood from escaping, keeping the body warmer 20.3 The topmost layer of the skin is the epidermis The dermis is the complex middle layer The innermost layer, attaching the skin to muscle, is the subcutaneous layer © 2011 The McGraw-Hill Companies, Inc All rights reserved 2053 In Summary (cont.) 20.4 The amount of melanin affects and determines skin color The amount of oxygen-carrying hemoglobin in our blood also affects skin color 20.5 Skin lesions are split among three main types: primary lesions such as macules and vesicles; secondary lesions include ulcers and keloids; vascular lesions involve blood vessels and include telangiectasias and ecchymoses 20.6 The accessory organs of skin include hair follicles, arrector pili muscles, sebaceous glands, sudoriferous glands, and keratin-filled nails © 2011 The McGraw-Hill Companies, Inc All rights reserved 2054 In Summary (cont.) 20.7 Injured skin becomes inflamed from dilating blood vessels which leak and cause swelling A blood clot is formed, which is replaced by a scab, which is then replaced by collagen fibers that produce scar tissue 20.8 Skin loses elasticity with aging as well as the youthful glow because of the loss of collagen and elastin fibers The loss of melanin also causes graying and thinning of the hair The loss of adipose tissue and decreased number of sudoriferous glands makes it difficult to readily adjust to temperature changes © 2011 The McGraw-Hill Companies, Inc All rights reserved 2055 In Summary (cont.) 20.9 First-degree burns affect only the epidermis and are known as superficial burns Second-degree burns or partial thickness burns involve both the epidermis and dermis Third-degree or full-thickness burns affect all skin layers and underlying structures, including muscle and bone 20.10 There are three types of skin cancer: basal cell, squamous cell, and malignant melanoma Signs of skin cancer vary, as the treatment methods for each type © 2011 The McGraw-Hill Companies, Inc All rights reserved 2056 In Summary (cont.) 20.11 Common skin disorders: the signs, symptoms, and treatments for these conditions are found in the Pathophysiology section at the end of the chapter 20.12 ABCDE is the acronym used to remember the signs of possible melanoma when looking at suspicious moles on the body A = Asymmetry, B = Border, C = Color, D = Diameter, and E = Evolving 20.13 The seven warning signs of cancer are: C = Change, A = A sore, U = Unusual, T = Thickening, I = Indigestion, O = Obvious change, and N = Nagging cough © 2011 The McGraw-Hill Companies, Inc All rights reserved 2057 End of Chapter 20 We may have different religions, different languages, different colored skin, but we all belong to one human race ~Kofi Annan © 2011 The McGraw-Hill Companies, Inc All rights reserved ... Types • Eccrine gland – Produce watery type of sweat – Activated by heat • Apocrine gland – Produce thicker type of sweat with more proteins – Concentrated in armpit and groin areas – Activated by... Composed of – Adipose (fat) and loose connective tissue – Blood vessels and nerves • Functions – Storage in adipose tissue – Cushions and insulates underlying structures To Figure of Skin © 201 1 The... reserved 20 13 Dermis • Deeper of the two skin layers • Contains all major tissue types, plus – Sudoriferous (sweat) glands – Sebaceous (oil) glands – Hair follicles and arrector pili muscles – Collagen,