© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-1 The Integumentary System

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-2 Learning Outcomes 24.1List the functions of skin. 24.2Explain the role of skin in regulating body temperature. 24.3Describe the layers of skin and the characteristics of each layer. 24.4Explain the factors that affect skin color. 24.5Identify and describe common skin lesions.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-3 Learning Outcomes (cont.) 24.6List the accessory organs of skin and describe their structures and functions. 24.7Explain the process of skin healing, including scar production. 24.8Describe the effects of aging on skin. 24.9List the different types of burns and describe their appearances and treatments.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-4 Learning Outcomes (cont.) 24.10Describe the causes, signs and symptoms, and treatments of various types of skin cancer Describe the causes, signs and symptoms, and treatments of common skin disorders Explain the ABCD rule and its use in evaluating melanoma Using the acronym CAUTION, list the seven warning signs of cancer.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-5 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.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-6 Functions of the Integumentary System  Protection First line of defense against  Bacteria  Viruses Protects underlying structures from  Ultraviolet (UV) radiation  Dehydration

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-7 Functions of the Integumentary System (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

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-8  Vitamin D production Needed for calcium absorption  Sensation Sensory receptors  Excretion Small amounts of waste products are lost through perspiration Functions of the Integumentary System (cont.)

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-9 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.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Structure of Skin  Epidermis  Dermis  Hypodermis or subcutaneous layer

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Structure: Epidermis  Most superficial layer  Two parts Stratum corneum  Outermost layer  Mostly dead cells form an impermeable layer Stratum basale (stratum germinativum)  Deepest layer  Cells constantly dividing and pushing older cells outward

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Structure: Epidermis (cont.)  Keratinocyte – most common Makes and accumulates keratin  Durable protein that makes the epidermis waterproof and resistant to pathogens  Melanocyte Makes the pigment melanin  Traps UV radiation and prevents damage to underlying layers of the skin

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Structure: 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, elastic, and nerve fibers Blood vessels  Binds the epidermis to the subcutaneous tissue

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Structure: Subcutaneous Layer  Hypodermis  Composed of Adipose (fat) and loose connective tissue Blood vessels and nerves  Functions Storage in adipose tissue Cushions and insulates underlying structures

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge Where are melanocytes and keratinocytes, and what is their function? ANSWER: Both are located in the epidermis of the skin. Keratinocytes make and accumulate keratin, which is a durable protein that makes the epidermis waterproof and resistant to pathogens. Melanocytes make the pigment melanin, which traps UV radiation and prevents damage to underlying layers of the skin.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Color  Determined by amount of melanin in the epidermis of skin  The more melanin, the darker the skin color Range is from yellowish to brownish

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Color (cont.)  Oxygenated blood Amount of oxygen dissolved in the hemoglobin of the red blood cells  Hemoglobin – a pigment in the RBCs If blood is well-oxygenated, skin will be pink If oxygen level in blood is low, skin will be pale or have a bluish color (cyanosis)

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge What affects skin color? ANSWER: The amount of melanin produced by the melanocytes and the oxygenation of the blood.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Lesions  Any variation in the skin As simple as a freckle As serious as a tumor

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Lesions (cont.) Lesion NameDescription BullaA large blister or cluster of blisters CicatrixA scar, usually inside a wound or tissue CrustDried blood or pus on the skin EcchymosisA black-and-blue mark or bruise ErosionA shallow area of skin worn away by friction or pressure ExcoriationA scratch; may be covered with dried blood

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Lesions (cont.) Lesion NameDescription FissureA crack in the skin’s surface KeloidAn overgrowth of scar tissue MaculeA flat skin discoloration, such as a freckle or a flat mole NoduleA large pimple or small node PapuleAn elevated mass similar to but smaller than a nodule PetechiaePinpoint skin hemorrhages that result from bleeding disorders

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Lesions (cont.) Lesion NameDescription PlaqueA small, flat, scaly area of skin PurpuraPurple-red bruises usually due to clotting abnormalities ScaleThin plaques of epithelial tissue on skin’s surface PustuleAn elevated (infected) lesion containing pus TumorA swelling of abnormal tissue growth

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Lesions (cont.) Lesion NameDescription UlcerA wound that results from tissue loss VesicleA blister WhealAnother term for hive

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge Match the following: ___ KeloidA. A blister ___ VesicleB. A crack in the skin’s surface ___ CrustC. An overgrowth of scar tissue ___ Fissure D. A small, flat scaly area of skin ___ Ulcer E. Dried blood or pus on the skin ___ PlaqueF. A wound that results from tissue loss A E B F D C ANSWER:

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Accessory Organs (cont.)  Hair follicles Tube-like depressions in the dermis of skin Generate hairs Alopecia (baldness) occurs when follicles die Arrector pili muscles attached to follicles cause goose bumps  Sebaceous glands Produce sebum to keep hair soft Prevent bacteria from growing on skin  Nails Protect the ends of fingers and toes Hard keratin

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Accessory Organs (cont.)  Sudoriferous (sweat) glands Located in the dermis of skin Types  Eccrine Produce watery type of sweat Activated by heat  Apocrine Produce thicker type of sweat with more proteins Concentrated in armpit and groin areas Activated by nervousness or stress

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Accessory Organs Hair follicle Sebaceous gland Sudoriferous gland

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Healing  Injury  inflammation Redness due to dilation of nearby blood vessels Swelling because vessels leak fluid into spaces between cells Pain because excess fluid activates pain receptors

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Healing (cont.)  Inflammation promotes healing Extra blood to area Extra nutrients for skin repair Defensive cells Injury occurs Blood clot forms Scab replaces blood clot Clotted blood and other dried tissue Collagen fibers replace scab Bind the edges of wound; major component of scars

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge How does inflammation promote healing of the skin? ANSWER: Inflammation promotes healing by bringing extra blood, nutrients for skin repair, and defensive cells to the area of injury.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin and Aging  Skin loses firmness due to Loss of elastic and collagen fibers in dermis Loss and shifting of underlying adipose tissues  Skin color changes Dermis becomes thinner and more transparent Paler due to decrease in circulation

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin and Aging (cont.)  Melanocytes decrease Those remaining gather  “age” spots Hair grays and becomes thinner  Decreased tolerance to temperature changes Sudoriferous glands decrease in number  Decreased perspiration, hard to adjust to high temperatures Loss in adipose tissue and decreased circulation  Increased sensitivity to cold

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge What happens to the skin in the elderly? ANSWER: As a person ages, the skin loses firmness, skin color changes, melanocytes decrease, and tolerance to temperature changes decreases due to a loss of adipose tissue and sweat glands.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer-The most common type of cancer  Cancer – abnormal cell mass  Two types of tumors: Benign – cells are not able to metastisize (move to new location) Malignant – cancerous cells that can metastisize Risks: 1.Skin type 2.Sun exposure 3.Family history 4.Age 5.Immunological status -and-human-body/human-body/skin-article/

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer Types  Basal cell carcinoma – least malignant and most common bump with pearly edge, rarely metastisizes, surgery

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer Continued  Squamous cell carcinoma – rapid growth, metastisizes to lymph nodes Scaly, red areas forming an ulcer, common on scalp, ears, hands & lower lip Surgery + radiation

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer Continued  Malignant melanoma – cancer of melanocytes, spreads rapidly, often deadly 5% of skin cancer is this type, often from pigmented mole Normal mole Malignant Melanoma

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer: summarized  Basal cell carcinoma – progresses slowly and rarely spreads to other body parts  Squamous cell carcinoma – more likely to spread to surrounding tissues  Malignant melanoma – more aggressive and occurs anywhere Most arise from melanocytes

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer: Basal Cell Carcinoma  Signs and symptoms New growth or sore that will not heal Waxy, smooth, red, pale, flat, or lumpy May or may not bleed  Treatment: Curettage and electrodessication Cryosurgery Mohs’ surgery Laser therapy

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer: Squamous Cell Carcinoma  Less common than basal cell carcinoma  Found on face, lips, ears, and backs of hands  Signs and symptoms and treatments are the same as for basal cell carcinoma

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer: 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

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer: Stages of Melanoma Stage 0Only found in epidermis Stage ISpread to epidermis and dermis (1 to 2 mm thick) Stage II2 to 4 mm thick plus ulceration Stage IIISpread to one or more lymph nodes Stage IVSpread to other body organs or lymph nodes far from original melanoma

© 2009 The McGraw-Hill Companies, Inc. All rights reserved ABCD Rule –for recognizing melanoma  A = Asymmetry – sides of mole do not match  B = Border irregularity – no smooth borders  C = Color – different colors, reds, tans, black, brown  D = Diameter – larger than 6 mm  You want moles to be symmetrical, smooth borders, one color and small!!

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Cancer: ABCD Rule A Asymmetry: The mole should not become asymmetrical B Border should not become irregular C Color should not change or become mixture of colors D Diameter should not grow larger than the diameter of a pencil eraser

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Cancer Warning Signs C –Change in bowel or bladder habits A –A sore that will not heal U –Unusual bleeding or discharge T –Thickening or lump I –Indigestion or difficulty swallowing O –Obvious change in wart or mole N –Nagging cough or hoarseness

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge True or False: ___ Basal cell carcinoma is the most aggressive form of skin cancer and can form anywhere. ___ Squamous cell carcinoma is more likely to spread to surrounding tissues. ___ Lesions of melanoma appear on trunk, head, neck of men and on arms and legs of women. ___ The borders of skin cancers are usually regular. ___ Basal cell carcinoma progresses slowly and rarely spreads to other body parts. ANSWER: F T T F T Melanomas are more aggressive. Borders are irregular.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Common Skin Disorders  Alopecia Results in hair loss  Cellulitis Inflammation of connective tissue in skin  Dermatitis Inflammation of skin or a rash  Eczema Chronic dermatitis  Folliculitis Inflammation of hair follicles

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Common Skin Disorders (cont.)  Herpes simplex Type 1 – cold sores Type 2 – genital  Herpes zoster Shingles  Impetigo Oozing skin lesions that eventually crust over  Pediculosis Head lice Body lice Pubic lice  Psoriasis Inherited autoimmune disorder

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Common Skin Disorders (cont.)  Ringworm Tinea corporis Tinea capitis Tinea pedis  Rosacea Dilation of small facial blood vessels  Scabies Contagious skin condition caused by mites  Warts Harmless growths caused by a virus

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge Match the following: ___ AlopeciaA. Dilation of small facial blood vessels ___ FolliculitisB. Inherited autoimmune disorder ___ ImpetigoC. Hair loss ___ PsoriasisD. Growths caused by a virus ___ RosaceaE. Inflammation of hair follicles ___ WartsF. Oozing skin lesions ANSWER: C F A B D E

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Skin Homeostatic Imbalances  BURNS: Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals Associated dangers  Body loses supply of fluids (proteins & electrolytes)  Infection RULE OF NINES: 11 areas of the body with 9% value each, + 1% perineum The higher the % the greater the risk of complications and death.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Severity of Burns  FIRST-DEGREE BURNS – partial thickness burn, epidermis damaged, red & swollen, 2-3 days to heal, “sunburn”  SECOND-DEGREE BURNS – partial thickness burn, epidermis and papillary layer burned, red with blisters Regrowth usually occurs with little to no scarring  THIRD-DEGREE BURNS – full thickness burn, area is blackened or gray/white, no pain (nerve endings burned off) Grafting must be done, scarring  Burns are considered critical if: over 25% of body has 2 nd degree burn, over 10% has 3 rd degree burns or 3 rd degree burns on hands/face/feet

© 2009 The McGraw-Hill Companies, Inc. All rights reserved (the skin gun)

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 24-54

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Burns: Treatment  Do not remove anything sticking to the burn  Do not apply butter, lotions, or ointments  Cool with large amounts of water  Cover with sterile sheet or plastic bag

© 2009 The McGraw-Hill Companies, Inc. All rights reserved Apply Your Knowledge Using Figure 24-5, determine burn severity for a patient who has burnt his anterior face and both arms. ANSWER: Head = 9% Both arms, hands, and shoulders = 18% + 18% 9% + 18% + 18% = 45%

© 2009 The McGraw-Hill Companies, Inc. All rights reserved 57 Homeostatic Skin Imbalances Directions: On a separate sheet of paper thoroughly answer the question below. Use appropriate academic vocabulary and clear and complete sentences. Name FOUR homeostatic imbalances that can occur in relation to the skin. Describe each problem in detail along with the underlying cause of each.

© 2009 The McGraw-Hill Companies, Inc. All rights reserved In Summary:  First line of defense for body  Protects the body from Invading organisms Chemicals UV light Water loss  Regulates body temperature  Understanding this system can help you be more effective in your role