J oe Pistack MS/ED

1. Integumentary System and Body Temperature-Chapter 7 Joe Pistack MS/ED

2. Integumentary system includes: The skin Accessory structures:- sweat glands -oil glands - hair - nails Integumentary System

3. The skin performs the following functions: • Keeps harmful substances out of the body and helps retain water and electrolytes. • Protects the internal structures and organs from injuries due to blows, cuts, harsh chemicals, sunlight burns, and pathogenic microorganisms. • Performs an excretory function. Secretes water and small amounts of urea. Functions of skin

4. Acts as a gland by synthesizing vitamin D. Vitamin D is necessary for absorption of calcium from the digestive tract. Performs a sensory role by housing the sensory receptors for touch, pressure, pain, and temperature. Plays an important role in the regulation of body temperature. Functions of the skin

5. Skin: Considered an organ Also called integument or cutaneous membrane Skin has 2 layers: Epidermis-outer layer Dermis-inner layer Dermatology-the study of skin and skin disorders. Structure of the skin

6. Epidermis-thin outer layer of skin. Composed of stratified squamous epithelium. Has no blood supply of it’s own, avascular. Oxygen and nutrients diffuse into the epidermis from blood supply from the dermis. Layers of skin

7. The epidermis can be divided into 5 layers the two of interest here are the deeper stratum germinativum and the more superficial stratum corneum 1.Stratum germinativum- -lies on top of the dermis. -has access to a rich supply of blood. -cells of this layer constantly divide, push old cells to the surface. Layers of skin

8. Changes take place as cells move away from surface: 1. cells begin to die 2. keratinization takes place Keratinization-process whereby tough protein called keratin is deposited within the cell, keratin hardens and flattens the cells as they move toward surface. This makes the skin water-resistant. Layers of skin

9. Stratum Corneum: • Surface layer of the epidermis. • Composed of about 30 layers of dead cells. • Dead cells are continuously sloughed off. • Sloughed cells are called dander, dandruff when clumped by oil on the skull. Layers of the skin

10. Insensible perspiration-500ml/day of perspiration that is lost through the skin. Sensible perspiration-due to activity of the sweat glands. If the epidermis is damaged, the rate of insensible perspiration increases. E.g. burns Levels of skin

11. Dermis: • Located under the epidermis. • Largest portion of the skin • Composed of dense, fibrous, connective tissue. • Contains collagen and elastin fibers that make the skin strong and stretchable. E.g. Pregnancy Levels of skin

12. Subcutaneous layer or hypodermis: • Not considered part of the skin, • Lies under the skin. • Composed primarily of loose connective and adipose tissue. Layers of skin

13. Subcutaneous tissue performs two main roles: • 1. Helps to insulate the body from extreme temperature changes in the external environment. • 2. Anchors the skin to the underlying structures. • Several areas of the body have no subcutaneous layer and are anchored directly to bone • Drugs are administered (SubQ) because hypodermis has a rich supply of blood vessels. Layers of skin

14. Layers of skin

15. SQ injections 22 to20 ga. 5/8 to 3/4 long

16. Skin color is determined by: Genetic factors Physiological factors Disease Melanocytes-skin cells within the epidermal layer. Melanin-darkening pigment, stains the surrounding cells causing them to darken. Skin color

17. The more melanin, the darker the skin. Amount of melanin secreted determines the skin color. Exposure to ultraviolet sunlight increases the secretion of melanin=suntan. Skin color

18. Conditions involving malfunctioning melanocyte: Albinism: - melanocytes fail to secrete melanin. - skin, hair, and iris (colored part of eye) are white. Vitiligo: -loss of pigment in certain areas of skin. -creates patches of white skin. Freckles and Moles: -Areas in the skin where melanin is concentrated Malignant melanoma -A mole that has changed in character and has become cancerous Malfunctioning melanocyte

19. Carotene-yellowish pigment to skin. Cyanosis-blue look to skin, result of poorly oxygenated blood. Blushing-dilation of the blood vessels. Pallor-constriction of blood vessels, decrease in oxygenated blood. Skin conditions

20. Accessory structures include: - hair - nails - glands Hairless body parts: palms of hands, soles of feet, lips, nipples, and parts of the external reproductive organs. Accessory structures

21. Chief parts: Shaft-part above the surface of the skin. Root-part that extends from the dermis to the surface. Hair follicle-formed by downward extension of epithelial cells. Parts of hair

22. Functions: Eyelashes and eyebrows-protect the eyes from dust and perspiration. Nasal hairs trap dust and prevent it from entering the lungs. Hair of the scalp keeps us warm. Functions of hair

23. Hair growth-influenced by sex hormones. Puberty-growth of hair in axillary and pubic areas in male and females. Hirsutism-excessive hair growth in females, caused by too much testosterone. Function of hair

24. Epidermal cells –receive blood supply from the dermal blood vessels. Keratinization of cells- cells die as they move away from their source of nourishment. Hair that we brush, blow dry, and curl is dead. Hair Follicle

25. Hair color: Genetically controlled by the amount of melanin. Abundance of melanin-dark hair. Less melanin-blond hair. Absence of melanin-white hair. Hair color

26. Shape of the hair shaft: Determines the appearance of hair. Round shaft produces straight hair. Oval shaft produces wavy hair. Flat hair shafts produce curly and kinky hair. Shape of hair

27. Hair Follicle

28. Arrector Pili muscle- attached to the hair follicle. Bundle of smooth muscle fibers, when these muscles contract, hair stands on end. Contract when cold or frightened. Also called goose bumps. Hair follicle

29. Hair standing on end

30. Alopecia-loss of hair. • Male-pattern baldness • most common type. • Characterized by a gradual loss of hair. • Drug toxicity • second most common type. • Eg. Chemo, radiation. Alopecia

31. Hair loss from radiation

32. Nails: Thin plates of stratified squamous epithelial cells. Contain a hard form of keratin. Found on the distal end of the fingers and toes. Protect structures from injury. nails

33. Structure: • Free edge • Nail body (finger nail) • Nail root Nail structure

34. Nail growth-determined by half-moon shaped lunula located at the base of the nail. As nail grows, it slides over the nailbed. Underlying dermal layer contains blood vessels which give pink color to nail. Cuticle-fold of stratum corneum-grows onto proximal portion of the nail body. Nail structure

35. Nail structure

36. nails

37. nails

38. Assessment of the nails should include: -shape -dorsal curvature -adhesion to the nail bed -color -thickness assessment

39. clubbing-condition that indicates fingertips have received an insufficient supply of oxygenated blood over a period of time. Fingertips become large, nails become think, hard, shiny and curved at the free end. Causes-chronic heart and lung disease. Nail conditions

40. Clubbing of fingers

41. Cyanosis-poor oxygenation makes the blood appear bluish, this in turn makes the nails appear bluish. Nail abuse-trauma to the nail that causes the nail to thicken and hypertrophy. Brittle- generally due to poor oxygenation or poor nutrition, or anemias. cyanosis

42. Cyanosis

43. Two major glands: Sebaceous glands Sweat glands Sebaceous glands or oil glands-associated with the hair follicles, found in all body areas that have hair. Sebum-oily substance that flows into hair follicle or onto surface of skin. glands

44. Function: Sebum lubricates and helps waterproof skin and hair. Inhibits bacteria on the surface of the skin. Production decreases with aging, results in dry skin and brittle hair. Vernix caseosa-cream cheese covering that babies are born with, secreted by sebaceous glands. glands

45. Glands can become blocked by accumulating sebum and debris. • A blackhead forms when sebum is exposed to air and dries out • A pimple forms when the blocked sebum becomes infected with staphylococci-it becomes a pustule Glands

46. Sebaceous glands

47. Sweat glands or sudoriferous glands: • Located in the dermis. • Secrete sweat. • Sweat is secreted into a duct that opens onto the skin as a pore. • We have approximately three million sweat glands. Sweat glands

48. Two types of sweat glands: 1) Apocrine glands-usually associated with the hair follicles, found in the axillary and genital areas. • Respond to emotional stress and become activated when a person is frightened, upset, in pain or sexually excited. • Become activated during puberty. Sweat glands

49. Body odor- occurs when the substances in sweat are degraded by bacteria into chemicals with a strong unpleasant odor. 2) Eccrine glands-more numerous and widely distirubuted throughout the body. Especially numerous on the forehead, neck, back, upper lip, palms, and soles. Sweat glands

50. Eccrine glands: • Not associated with hair follicles. • Sweat that is secreted plays an important role in temperature regulation. • As sweat evaporates on the skin, heat is lost. • Sensible perspiration-secreted by the eccrine glands, can secrete a gallon of sweat per hour. Glands