Integumentary System

1. Integumentary System The Skin

2. Integumentary System • AKA: skin • Also called a membrane (because it covers the body) and an organ (because it contains several kinds of tissues) • Avg: covers more than 3,000 sq in of surface area • Accounts for 15% of total body weight

3. 3 Layers of the Skin • Epidermis: the outermost layer • Actually made of 5 smaller layers but no blood vessels or cells • Two main layers: stratum corneum (outermost) and stratum germinativum (innermost) • Outermost layer constantly sheds dead cells while innermost layer replenishes the lost cells

4. 3 Layers of the Skin • Dermis: (corium) “true skin”; has a framework of elastic connective tissue, contains blood vessels, lymph vessels, nerves, involuntary muscle, sweat and oil glands, and hair follicles • top of the dermis is covered with papillae • Fit into ridges on the stratum germinativum of the epidermis

5. 3 Layers of the Skin • Those ridges form lines (striations) on the skin • This is what causes fingerprints and footprints

6. 3 Layers of the Skin • Subcutaneous Fascia (hypodermis): innermost layer • made of elastic and fibrous connective tissue and adipose tissue • connects the skin to underlying muscles

8. Integumentary System • Two main types of glands: sudoriferous and sebaceous • Sudoiferous glands: (sweat glands) coiled tubes that extend via the dermis and open on the surface of the skin at pores • Sweat/perspiration eliminated by the glands contains water, salt, and some body waste • Basically odorless

9. Integumentary System • When sweat interacts with bacteria on the skin, body odor occurs • Process of sweating removes excess water from the body and cools the body as sweat evaporates into the air

10. Integumentary System • Sebaceous glands: oil glands that usually open onto hair follicles • Produce sebum (an oil that keeps the skin and hair from becoming dry and brittle) • Slightly acidic • Acts as an antibacterial and antifungal secretion to help prevent infections

11. Integumentary System • When an oil gland becomes plugged, the result is a blackhead or pimple

12. Hair • Each hair consists of a root (which grows in a hollow tube called a follicle) and a hair shaft • Helps protect the body and covers all body surfaces except for the palms and soles • Alopecia: baldness; permanent hair loss on the scalp (caused by genetics)

13. Nails • Protect the fingers and toes from injury • Made of dead keratinized epidermal epithelial cells packed closely together to form a thick, dense surface • Formed in the nail bed • If lost, nails will regrow if the nail bed is not damaged

15. Functions • Protection: barrier to UV rays and invasion of pathogens; holds in moisture • Sensory Perception: respond to pain, pressure, temperature, and touch • Body Temperature Regulation: help the body retain or lose heat • When blood vessels dilate, excess heat from the blood can escape via the skin

16. Functions • Dilate: get larger • When the blood vessels constrict, the heat is retained in the body • Constrict: get smaller • Storage: temporary storage of fat, glucose, water, vitamins, and salts

17. Functions • Absorption: medications for motion sickness or heart disease and nicotine patches • Transdermal Medication: medications are placed on sticky patches and applied to the skin • Excretion: helps the body eliminate salt, a minute amount of waste, and excess water and heat via perspiration

18. Functions • Production: helps in the production of vitamin D by using UV rays from the sun to form an initial molecule of vitamin D that matures in the liver

19. Pigmentation • Basic skin color is inherited and is determined by pigments in the epidermis of the skin • Melanin: brownish black pigment that’s produced in the epidermis by specialized cells called melanocytes • Everyone has the same number of melanocytes

20. Pigmentation • Melanin can lead to a black, brown, or yellow skin tint • UV light activates the melanocytes to produce more melanin to protect and to tan the skin • Freckles: small concentrated areas of melanin pigment • Carotene: a yellowish, red pigment, also helps determine skin color

21. Pigmentation • Albino: a person with an absence of color pigments • Has a pinkish tint and the hair is pale yellow or white • Their eyes also lack pigment and are red and very sensitive to light

23. Pigmentation • Abnormal colors of the skin can indicate disease • Erythema: a reddish color of the skin that can be caused by either burns or a congestion of blood in the vessels • Jaundice: a yellow discoloration of the skin • Can indicate bile in the blood as a result of liver or gallbladder disease

24. Pigmentation • Jaundice also occurs in conjunction with certain diseases that involve the destruction of RBC • Cyanosis: a bluish discoloration of the skin caused by insufficient oxygen • Can be associated with heart, lung, and circulatory diseases or disorders • Chronic poisoning may cause a gray or brown skin discoloration

25. Skin Eruptions • Macules: flat spots on the skin, such as freckles • Papules: firm, raised areas such as pimples and the eruptions seen in some stages or chickenpox and syphilis • Vesicles: blisters, or fluid-filled sacs, such as those seen in chickenpox • Pustules: pus-filled sacs such as those seen in acne, or pimples

26. Macules

27. Papules

28. Vesicles

29. Pustules

30. Skin Eruptions • Crusts: areas of dried pus and blood, commonly called scabs • Wheals: itchy, elevated areas with an irregular shape; hives and insect bites are examples • Ulcer: a deep loss of skin surface that may extend into the dermis; may cause periodic bleeding and the formation of scars

31. Crusts

32. Wheals

33. Ulcer

34. Ulcer

35. Acne Vulgaris • An inflammation of the sebaceous glands • Cause is unknown, but usually occurs in adolescence • Symptoms: papules, pustules, and black heads • Occur when follicles become blocked • Tx: frequent, thorough skin washing, avoid creams and heavy makeup, antibiotic or vitamin A ointments, oral antibiotics, & UV light

36. Athlete’s Foot • A contagious fungal infection that usually affects the feet • Symptoms: itchiness, blisters, cracks, open sores • Tx: antifungal medication and keeping the area clean and dry

37. Skin Cancer • Most common type of cancer • 3 main types of skin cancer • Basal Cell Carcinoma • Squamous Cell Carcinoma • Melanoma

38. Basal Cell Carcinoma • cancer of the basal cells in the epidermis of the skin • grows slowly and does not usually spread • Lesions can be pink to yellow-white • Usually smooth with a depressed center and an elevated, irregular-shaped border

39. Squamous Cell Carcinoma • Affects the thin cells of the epithelium but can spread quickly to other areas of the body • Start as small, firm, red, flat sores that later scale and crust • Sores that do not heal are frequently squamous cell carcinomas

40. Melanoma • Develops in the melanocytes of the epidermis and is the most dangerous type of skin cancer • Lesions can be brown, black, pink, or multicolored • Usually flat or raised slightly, asymmetric and irregular notched on the edges

41. Skin Cancer • Usually develops as a mole or nevus that changes in color, shape, size or texture • Bleeding or itching of a mole can indicate cancer • Causes: exposure to the sun, prolonged use of tanning beds, irritating chemicals, radiation • Tx: surgical removal of the cancer, radiation, &/or chemotherapy

42. Dermatitis • An inflammation of the skin • Can be caused by any substance that irritates the skin • Frequently, an allergic reaction to detergents, cosmetics, pollen, or certain foods • Symptoms: dry skin, erythema, itching, edema, macular-papular rashes, and scaling

43. Dermatitis • Tx: eliminating the cause; anti-inflammatory ointments, antihistamines, &/or steroids

44. Eczema • A noncontagious, inflammatory skin disorder caused by an allergen or irritant • Causes: diet, cosmetics, soaps, medications, and emotional stress • Symptoms: dryness, erythema, edema, itching, vesicles, crusts, and scaling • Tx: removing the irritant; corticosteroids

45. Eczema

46. Impetigo • A highly contagious skin infection usually caused by streptococci and staphylococci organisms • Symptoms: erythema, oozing vesicles, pustules, and the formation of a yellow crust • Lesions should be washed with soap and water and kept dry • Tx: antibiotics (topical and oral)

47. Impetigo

48. Psoriasis • A chronic, noncontagious skin disease with periods of exacerbations and remission • Cause: unknown • Cause of exacerbation: stress, cold weather, sunlight, pregnancy, and endocrine changes • Symptoms: thick, red areas covered with white or silver scales • No cure but tx: coal/tar or corticosteroids ointments, UV light, &/or scale removal

49. Psoriasis

50. Ringworm • A highly contagious fungal infection of the skin or scalp • Symptoms: formation of a flat or raised circular area with a clear central area surrounded by an itchy, scaly, or crusty outer ring • Tx: antifungal medications (oral and topical)