INTEGUMENTARY SYSTEM Chapter 5

©2004 Delmar Learning, a Division of Thomson Learning, Inc. FUNCTIONS OF THE SKIN The skin has 7 functions: –Covers underlying tissues to protect against dehydration, injury, and germ invasion –Regulates body temperature –Helps manufacture vitamin D –Serves as the site of many nerve endings

©2004 Delmar Learning, a Division of Thomson Learning, Inc. FUNCTIONS OF THE SKIN –Temporarily stores fat, glucose, water, and salts –Screens out ultraviolet radiation –Absorbs certain drugs and chemical substances

©2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE SKIN Layers of the skin: –Epidermis - the outermost covering of epithelial cells with no blood vessels –Dermis - true skin made of connective tissue and is vascular –Subcutaneous (hypodermal layer) lies under the dermis and consists of loose connective tissue

©2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE SKIN

©2004 Delmar Learning, a Division of Thomson Learning, Inc. APPENDAGES OF THE SKIN Hair Nails Sweat Glands Sebaceous Glands

©2004 Delmar Learning, a Division of Thomson Learning, Inc. THE INTEGUMENT AND ITS RELATIONSHIP TO MICROORGANISMS Most skin bacteria are associated with hair follicles or sweat glands where nutrients and moisture are present The best way to prevent disease is by washing the hands

©2004 Delmar Learning, a Division of Thomson Learning, Inc. REPRESENTATIVE DISORDERS OF THE SKIN Acne vulgaris Athlete’s foot Dermatitis Eczema Impetigo Psoriasis Ringworm Urticaria (hives) Boils Herpes Genital herpes Shingles (herpes zoster)

©2004 Delmar Learning, a Division of Thomson Learning, Inc. SKIN CANCER Basal cell carcinoma is the most common and least malignant skin cancer Squamous cell carcinoma occurs in the epidermis and grows rapidly Malignant melanoma is present in pigmented cells called melanocytes

©2004 Delmar Learning, a Division of Thomson Learning, Inc. BURNS Burns are the result of radiation from sun, heat, boiling water, steam, fire, chemicals, and electricity

©2004 Delmar Learning, a Division of Thomson Learning, Inc. BURNS Classification of burns –First degree burns epidermis –Second degree burns epidermis and dermis –Third degree burns destruction of epidermis, dermis, and subcutaneous

©2004 Delmar Learning, a Division of Thomson Learning, Inc. SKIN LESIONS Pressure Ulcers (Decubitus) are the result of constant pressure against an area of tissue that lies over a bone

©2004 Delmar Learning, a Division of Thomson Learning, Inc. SKIN LESIONS 4 Stages of pressure ulcers are: –Stage I - skin is red but unbroken –Stage II - blisters; broken or unbroken –Stage III - all layers of skin are broken –Stage IV - ulcerated area involves underlying muscles, tendons, and bones