1. Integumentary System Allied Health Science I Michelle Garon

2. Layers of Skin 1. Epidermis (outer layer of the skin): made up of epithelial cells with no blood vessels present (avascular) 2. Dermis (true skin): made up of connective tissue and is vascular.

3. Epidermis Layer 1. Stratum corneum (outermost layer of the epidermis) 2. Stratum germinativum (innermost layer of epidermis)

4. Stratum Corneum 1. Contains hard nonliving protein called Keratin 2. Keratin makes our skin waterproof 3. Cells in this layer are flat and scalelike. They flake off from constant friction of clothing, rubbing, and washing 4.This layer can also be called the horny layer 5.As these cells flake off, they are replaced by new cells from the lower stratum germinativum

5. Stratum Corneum cont… 6. Stratum corneum is our body’s first line of defense 7. It is acidic and therefore many organisms are destroyed just by coming in contact with it 8. The thickness of this layer varies over the body –Thickest on palms of hands and soles of feet –If thickness grow outward = calluses –If thickness grows inward = corn

6. Stratum Germinativum Inner epidermal layer Cell division takes place here Skin pigment is found in melanocytes in this layer Skin pigment = melanin Melanin can be brown, black, or yellow depending on racial origin Freckles = patchy melanin Absence of pigments = albinism

7. Stratum Germinativum cont… Environment can alter skin color (sun exposure can cause temporary increase in melanin) Prolonged exposure to sun = skin cancer Lower edges of SG grow into ridges These ridges are papillae. –These are pronounced in hands and feet –These provide maximum resistance to slipping when grasping & holding objects – (friction ridges) –Ridges on fingers = fingerprints

8. Dermis Also called corium Thicker inner layer of skin Contains connective tissue, collagen, elastic fibers, nerve endings, muscles, hair follicles, oil and sweat glands, and fat cells.

9. Nerve Receptors in Dermis We have many different kind of nerve receptors in this dermal layer Sensory nerves = sensitive to heat, cold, touch, pain and pressure The nerve endings vary in where they are located. Receptors for touch are closer to epidermis so that you can feel someone touch you Pressure receptors are deeper in the dermal layer Pain receptors are numerous in your lower arm, breast, and forehead

10. Subcutaneous Layer Also called hypodermal layer Not a true part of integumentary system Made up of connective tissue and fat This layer attaches the integumentary system to the muscles underneath Injections/shots given in this area are called hypodermic or subcutaneous

11. Appendages of the Skin 1. Hair 2. Nails 3. Sudoriferous (sweat) glands 4. Sebaceous (oil) glands 5. Ducts of these glands

12. Hairs Distributed all over surface of body Not on palms of hands, soles of feet, penis, inner surfaces of vagina The length, thickness, type, and color of hair varies with location on body and racial origin

13. Hair Composition Root shaft – outer cuticle layer –Root = part of hair that is beneath skin, embedded in epidermis called hair follicle (the lower end of hair follicle is a tuft of tissue call the papilla) –The papilla has blood vessel and so it feeds the hair follicle cells –Shaft = part of hair that projects from skin surface Cortex – middle layer –Hair pigment located here Medulla – inner layer

14. Misc. Hair Facts Arrector pili muscle – located around each hair follicle –When this muscle contracts it causes “goose bumps”

15. Nails Hard surfaces covering dorsal surfaces of phalanges of fingers and toes Nail bed = matrix

16. Functions of Skin 1. Protects – covers deeper tissues protecting them from dehydration, injury, and germ invasion 2. Temperature regulation –Control heat loss –Perspiration 3. Helps to make vitamin D

17. Functions of Skin cont… 4. Site of many nerve endings 5. Contains tissues for temporary storage of fat, glucose, water, salts 6. Screens out harmful UV radiation in sunlight 7. Absorption – certain drugs (ex. Nitro- Bid paste)

18. Sweat Glands Also called sudoriferous glands All over body Is large numbers under arm (axilla), palms of hands, soles of feet, and forehead Sweat duct is tubular in shape and goes from gland up to pore in skin Sweat glands can be stimulated by heat, pain, fever, and nervousness by the nervous system

19. Sweat Glands cont… Perspiration is 99% water with small amounts of salt and other waste products It is vital that we replace the water we lose through sweating by drinking water so that our body can maintain homeostasis

20. Oil Glands Also called sebaceous glands These glands secrete sebum which is a thick, oily substance that protects and lubricates skin (keeps our skin soft and pliable

21. The Integument & It’s Relationship to Microorganisms Intact skin is best way body can defend itself against pathogens (disease-causing organisms), toxins, & water loss Skin is dry (organisms like moist environments) Most skin bacteria are associated with hair follicles or sweat glands where nutrients are present and moisture content is higher

22. The Integument & It’s Relationship to Microorganisms cont… Underarm perspiration odor is caused by bacteria mixing with the sweat

23. The Integument & It’s Relationship to Microorganisms cont… HC workers must know the #1 way to prevent the spread of disease is by WASHING HANDS PROPERLY Warm water Fingertips down Do not touch sink or surrounding surfaces At least 10-30 seconds 2-4 minutes if hands in contact with infectious material

24. Disorders of the Skin Acne Vulgaris – common and chronic disorder of the sebaceous glands –Oil glands produce excess sebum, this becomes hardened and plugs up the opening of the gland, area becomes filled with leukocytes (WBC’s), leukocytes cause pus formation –Occurs most often in adolescence (blackheads, cysts, pimples, & scarring

25. Athlete’s Foot Contagious fungal infection Occurs on superficial layers of skin usually between fingers and toes initially Usually contracted in public baths/showers Do not share towels/washclothes, socks, shoes, etc Tx = cleansing & drying area, antifungal medication

26. Dermatitis Inflammation of skin (nonspecific) Some people get this from using certain types of soaps/detergents

27. Eczema Acute/chronic noncontagious inflammatory skin disease Skin is dry, red, itchy, scaly Causes = allergies, drugs, artificial sunlight Tx = removal of causative agent

28. Impetigo Acute, inflammatory, contagious skin disease Seen is babies/young children Caused by a staph/strep microorganism Blisters form, rupture, and crust over yellow

29. Psoriasis Chronic inflammatory skin disease Dry reddish patches that are covered by silvery-white scales Elbows, knees, shins, scalp Triggered by stress, trauma, & infection

30. Ringworm Highly contagious fungal infection Raised, itchy, circular patches with crusts On skin, scalp, or underneath nails Tx = drug call Griseofulvin

31. Utricaria/Hives Intensely itching wheals or welts Welts are usually elevated with white center and surrounding pink area Usually in response to an allergen

32. Boils Painful bump Bacterial infection of hair follicle/sebaceous gland Caused by staph organism Tx = antibiotics, excision, and drainage of affected area

33. Shingles (Herpes Zoster) Skin eruption Caused by the virus that causes chicken pox in children Causes severe pain (neuralgia) Especially serious in the elderly or debilitated persons Tx = medication for pain and itching, protect the affected area from friction

34. Herpes Viral infection Fever blister or cold sore Spread through oral contact or respiratory route

35. Genital Herpes Caused by a virus Blister in genital area Spread through sexual contact Periods of exacerbation (outbreak) and remission Tx = Acyclovir Causes problems if woman becomes pregnant (baby would be exposed to this if delivered vaginally)

36. Skin Cancer Associated with exposure to UV light Most common type of cancer –Basal cell carcinoma most common type of skin cancer usually occurs on face Tx = surgical removal and radiation Good prognosis

37. Skin Cancer cont… –Squamous cell carcinoma Occurs most often on scalp and lower lip Grows rapidly and metastasizes to lymph nodes Tx = surgical removal, radiation If found early, prognosis is good –Malignant melanoma Occurs in melanocytes (pigment cells) Cancer cells spread quickly to other parts of body Tx = removal of cancer and surrounding area, chemotherapy –***This may be a brown irregular patch that appears suddenly

38. Burns When skin is burnt = dehydration and infection may occur (this can be life- threatening) The “rule of nines” measures the percent of body burned –Body is divided into 11 areas and each area accounts of 9% of total body surface

39. First Degree Burns Involves only epidermis Sx = redness, swelling, and pain Tx = cold water Healing occurs in about one week

40. Second Degree Burns Involves epidermis and dermis Sx = pain, swelling, redness, and blistering Risk of infection with open wounds Tx = pain medication, dry sterile dressing to open areas Healing occurs w/i 2 weeks

41. Third Degree Burns Involve complete destruction of epidermis, dermis, and subcutaneous layers Sx = loss of skin, eschar (blackened skin), yet there may be no pain Life-threatening condition depending on amount of skin damaged, fluid/blood/plasma lost Tx = immediate hospitalization to prevent infection, contracture, and fluid replacement Skin grafting is done asap