Integumentary System Chapter 5 Page 65 Integumentary System

Integumentary System Chapter 5

Page 65 Integumentary System v Made up of skin & its appendages • Hair • Nails • Sebaceous glands • Sweat glands v Integumentary v 3, 000 means “covering” square inches of surface area

Page 65 Functions of the Skin v Covering v Regulate body temperature v Manufacture v Nerve Vitamin D receptors v Temporary storage of fat, glucose, water & salts v Screen out ultraviolet radiation v Special absorptive properties

Page 65 Structure of the Skin v Epidermis • • v Outermost covering Avascular Dermis • • • True skin Connective tissue Vascular

Page 66 Figure 5 - 2

Page 65 Epidermal Cells v Keratinocytes – comprise most of the epidermis & produce keratin v Merkel cells – Sensory receptors for touch v Melanocytes – Produce the pigment melanin which protects the skin against the ultraviolet rays of the sun v Langerhans cells – Macrophages that defend against microorganisms

Page 67 Epidermal Layers v Stratum germinativum – Deepest epidermal layer; undergoes continuous cell division. Papillae originate in this layer (fingerprint). v Stratum spinosum – 8 -10 cell layers thick v Stratum granulosum – Where keratinization occurs v Stratum lucidum – Palms & soles v Stratum corneum – Dead cell layer

Page 67 v Three • • • Skin Color pigments contribute to skin color: Melanin – produces two distinct classes of melanin ü Pheomelanin – which is red to yellow ü Eumelanin – which is dark brown to black Carotene – a yellow to orange pigment found in certain plants. Hemoglobin – pinkish color of some fairskinned people is due to the presence of oxygen in the hemoglobin

Pages 67 – 68 Dermis (Corium) v Thicker, inner layer of the skin below the epidermis v Composed of: • • • dense connective tissue collagen tissue bands elastic fibers muscle fibers some mast cells white blood cells • • oil & fat glands fat cells Many nerve receptors Blood vessels & heat regulation

Page 68 Subcutaneous Layer v Also v Not called hypodermal layer (Lies under dermis) a true part of the integumentary system v Attaches integumentary system to the surface muscles underneath

Page 68 Appendages - Hair v Hair is composed of Root shaft, Outer cuticle layer, the Cortex & the Inner medulla. • Root = the part of the hair that is implanted in the skin. • Shaft = projects from the skin’s surface • Hair follicle = an inpocketing of the epidermis where the hair is embedded. The shape determines the curl of the hair. v Arrector pili muscle – attached to the hair & when you get chilled your hair stands up.

Page 69 Figure 5 – 3

Page 69 Appendages - Nails v Hard structures covering the dorsal surfaces of the last phalanges of the fingers & toes v Formed in the nail bed or matrix v Lunula: white crescent at the proximal end of the nail

Page 69 Figure 5 – 4

Page 70 Appendages – Nails (Cont’d) Disease Condition & Nail Color Condition Nail Color liver disease white nails half of nail is pink; half is kidney disease white heart condition nail bed is red lung disease yellow & thickening nails Anemia pale nail bed yellowish with a slight blush diabetes at the base hypoxia bluish nails

Pages 69 – 70 Appendages – Sweat Glands v Also called sudoriferous glands v Perspiration is 99% water; it is excreted through pores v Under the control of the nervous system, these glands may be activated by several factors including heat, pain, fever, & nervousness. v 500 ml water lost per day through the skin v Ceruminous or wax glands are modified sweat glands & are found in ear canals

Page 70 Sebaceous Glands v Secretes v Sebum pliable sebum which is thick, oily substance lubricates the skin, keeping it soft &

Page 70 v Intact Microorganisms skin is the best way to protect against pathogens v Most skin bacteria are associated with hair follicles & sweat glands Handwashing v Most effective action to prevent spread of disease • 20 seconds for washing hands • 2– 4 minutes for infectious material

Page 71 SB Aging Skin v Becomes more fragile and dry v Loss of elasticity v Less effective body temperature control v Melanocytes decrease v Physiological changes can impact self-worth

Pages 70 – 71 Disorders of the Skin Acne vulgaris v Common & chronic disorder of sebaceous glands v Occurs mostly during adolescence & marked by blackheads, cysts, pimples and scarring Athlete’s foot v Contagious fungal infection v Blisters between fingers & toes causing cracking & scaling Dermatitis v Non-contagious inflammation of the skin

Page 71 Disorders of the Skin (Cont’d) Eczema v Acute or chronic, noncontagious inflammatory skin disease v Dry, red, itchy & scaly Impetigo v Acute, inflammatory, & contagious skin disease v Caused typically by staph or strep v Honey crusted exudates

Page 71 Disorders of the Skin (Cont’d) Psoriasis v Chronic inflammatory skin disease (reddish patches covered by silvery-white scales) v Autoimmune disease triggered by stress, trauma or infection Ringworm v Highly contagious fungal infection v Red, circular patches with scaly borders Urticaria (hives) v Intensely itchy, red, raised wheals or welts v Response to an allergen

Page 73 Disorders of the Skin (Cont’d) Boils (carbuncles) v Painful, bacterial infection of the hair follicles or sebaceous glands v May require an incision and drainage Rosacea v Common inflammatory disorder (chronic redness and irritation to the face) v Triggers include stress, caffeine, hot foods, and alcohol

Page 73 Disorders of the Skin (Cont’d) Herpes v Viral infection that is usually seen as a blister v Simplex includes cold sores involving the lips or beneath the nose Genital herpes v Virus that may appear as a blister in the genital area; this is covered in Chapter 21 Shingles (herpes zoster) v Skin eruption due to a viral infection of the nerve ending v Reactivation of the chicken pox virus (varicella)

Page 73 Disorders of the Hair & Nails Head lice v Parasitic v Intense insects itching & sores on the head Ingrown nails v Common nail problem Fungal infections v Infections v Makes of the nail up 50% of all nail problems

Page 73 Disorders of the Hair & Nails (Cont’d) Warts v Viral infections that affect the skin surrounding or underneath the nail v Caused by human papilloma virus (HPV)

Pages 73 – 74 v Basal Skin Cancer cell carcinoma = Most common & least malignant v Squamous cell carcinoma = Most often found on the scalp & lower lip v Malignant melanoma = Metastasizes to other areas quickly v Change in color, size, shape of a mole

Pages 74 – 76 v Rule Burns of nines – measures the percent of the body burned; the body is divided into 11 areas & each area = 9% of the body v First-degree burns = Superficial, epidermis only, no blister, redness swelling & pain v Second-degree burns = Epidermis & dermis, blister forms v Third-degree burns = Complete destruction of epidermis, dermis & subcutaneous layers forming an eschar (black skin)

Page 76 Skin Lesions v Abrasion = an injury in which superficial layers of the skin are scraped or rubbed away. v Fissure = a groove or crack like break in the skin v Laceration = a torn or jagged wound

Page 76 Pressure ulcer (decubitus ulcers) v v v Also known as Bedsores they occur along the spine, coccyx, hips, elbows & heels • Preventable & are a primary concern of health care professionals. Stage I – Redness only, skin intact Stage II – Blistered skin, broken or unbroken Stage III – Skin breaks through all layers Stage IV – Ulceration to underlying muscle & bone

Page 79 Figure 5 – 10