Transcript skin
Chapter 5 Integumentary System © 2009 Delmar, Cengage Learning Integumentary System • Skin and its appendages – – – – Hair Nails Sebaceous glands Sweat glands • Integumentary means covering • 3,000 square inches of surface area © 2009 Delmar, Cengage Learning Functions of Skin • • • • Covering Regulate body temperature Manufacture Vitamin D Nerve receptors © 2009 Delmar, Cengage Learning Functions of Skin • Temporary storage • Screen out ultraviolet radiation • Special absorptive properties © 2009 Delmar, Cengage Learning Structure of the Skin • Epidermis – Outermost covering – Avascular • Dermis – Connective tissue – Vascular / Receptors © 2009 Delmar, Cengage Learning Structure of the Skin © 2009 Delmar, Cengage Learning Epidermal Cells • • • • Keratinocytes- gives strength Merkel cells- sensory touch Melanocytes- protect against UV Langerhans cells- part of immune © 2009 Delmar, Cengage Learning Epidermal Layers (5) • • • • • Stratum germinativum Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum © 2009 Delmar, Cengage Learning Dermis • Thicker, inner layer of the skin • Many nerve receptors • Blood vessels and heat regulation © 2009 Delmar, Cengage Learning Subcutaneous Layer • Lies under dermis • Not a true part of the integumentary system • Attaches integumentary system to the surface muscles underneath © 2009 Delmar, Cengage Learning Different parts of the skin- Hair • • • • Root shaft – part that is showing (pg. 76) Medulla- Inner part Hair follicle-embedded Arrector pili muscle © 2009 Delmar, Cengage Learning Appendages Nails • Hard structures covering – phalanges of the fingers and toes • Nail bed or matrix • Diseases and nail color © 2009 Delmar, Cengage Learning Appendages Sweat Glands • • • • Perspiration 99% water Perspiration is excreted through pores Under the control of the nervous system 500ml water lost per day through skin (.5 gal) © 2009 Delmar, Cengage Learning Sebaceous Glands • Secrete sebum which is thick, oily substance • Sebum lubricates the skin, keeping it soft and pliable © 2009 Delmar, Cengage Learning Microorganisms • Intact skin is the best way to protect itself against pathogens • Most skin bacteria are associated with hair follicles and sweat glands • Handwashing – Most effective action to prevent spread of disease • 20 seconds for washing hands • 2-4 minutes for infectious material © 2009 Delmar, Cengage Learning Aging • • • • Becomes more fragile and dry Loss of elasticity Less effective body temperature control Melanocytes decrease © 2009 Delmar, Cengage Learning Disorders Skin • Acne vulgaris – Common and chronic disorder of sebaceous glands • Athlete’s foot – Contagious fungal infection • Dermatitis – Inflammation of the skin © 2009 Delmar, Cengage Learning Disorders Skin • Eczema – Acute or chronic, noncontagious inflammatory skin disease • Impetigo – Acute, inflammatory, and contagious skin disease caused by staph • Psoriasis – Chronic inflammatory skin disease (reddish patches covered by silvery-white scales) © 2009 Delmar, Cengage Learning Disorders Skin • Ringworm – Highly contagious fungal infection • Urticaria (hives) – Intensely itching wheals or welts • Boils (carbuncles) – Painful, bacterial infection of the hair follicles or sebaceous glands © 2009 Delmar, Cengage Learning Disorders Skin • Rosacea – Common inflammatory disorder (chronic redness and irritation to the face) • Herpes – Viral infection which is usually seen as a blister © 2009 Delmar, Cengage Learning Disorders Skin • Genital herpes – Virus which may appear as a blister in the genital area • Shingle (herpes zoster) – Skin eruption due to a virus infection of the nerve ending © 2009 Delmar, Cengage Learning Disorders Hair and Nails • Head lice – Parasitic insects • Ingrown nails – Common nail problem © 2009 Delmar, Cengage Learning Disorders Hair and Nails • Fungal infections – Infections of the nail • Warts – Viral infections that affect the skin surrounding or underneath the nail © 2009 Delmar, Cengage Learning Skin Cancer • Basal cell carcinoma • Squamous cell carcinoma • Malignant melanoma • Skin and sun exposure © 2009 Delmar, Cengage Learning Burns • Rule of nines – Body divided into 11 area; each part is 9% • First degree burns • Second degree burns • Third degree burns © 2009 Delmar, Cengage Learning Skin Lesions • Pressure ulcer (decubitus ulcers) – – – – Stage I Stage II Stage III Stage IV © 2009 Delmar, Cengage Learning