Hole s Human Anatomy and Physiology Eleventh Edition Mrs. Hummer Chapter 6 1
Chapter 6 Skin and the Integumentary System Composed of several tissues Maintains homeostasis Protective covering Retards water loss Regulates body temperature Houses sensory receptors Contains immune system cells Synthesizes chemicals (vitamin D) Excretes small amounts of waste 2
help produce Vitamin D needed for normal bone and tooth development some cells (keratinocytes) produce substances that simulate development of some WBCs 3
Layers of Skin Epidermis outer layer Dermis Inner layer Subcutaneous layer beneath dermis not part of skin 4
Subcutaneous Layer hypodermis adipose tissue insulates contains the major blood vessels that supply the skin 5
Epidermis lacks blood vessels keratinized - hardened keratonized masses on toes are called corns thickest on palms and soles (0.8-1.4mm) melanocytes provide melanin rests on basement membrane composed of stratified squamous 6
Dermis on average 1.0-2.0mm thick contains dermal papillae binds epidermis to underlying tissues irregular dense connective tissue muscle cells and nerve cells present specialized sensory receptors blood vessels 7
Understanding Words 1. What are the layers of the skin? Notebook 2. What causes the characteristic lesions of psoriasis? 3. How do allergic contact dermatitis and irritant contact dermatitis differ? 4. Why is water not absorbed through the skin? 5. Cancer of the skin can arise from the deep layers of the or from pigmented. 6. Deep layers of the skin are protected from the ultraviolet portion of sunlight by. 7. How do the patterns of fingerprints form? 8. What types of muscle cells are found in the dermis? 8
Hair Follicles epidermal cells tube-like depression extends into dermis hair root, shaft, papilla dead epidermal cells arrector pili muscle - makes the hair stand up loose 20-100 hairs per day 9
Nails protective coverings nail plate nail bed lunula 10
Sebaceous Glands usually associated with hair follicles holocrine glands secrete sebum-fatty material and cellular debris absent on palms and soles 11
Sweat Glands sudoriferous glands widespread in skin originates in deeper dermis or hypodermis eccrine glands- most numerous (maintain body temp.) apocrine glands- develop a scent ceruminous glands- secrete ear wax mammary glands- make milk 12
Regulation of Body Temperature 13
Problems in Temperature Regulation Hyperthermia abnormally high body temperature Hypothermia abnormally low body temperature 14
Notebook 1. What is folliculitis? 2. Describe several forms of baldness. 3. How is baldness treated? How effective are the various treatments for baldness? 4. Explain how various hair colors are produced. 5. Describe how hair responds to cold temperatures or strong emotions. 6. Where is the growing portion of the nail located? 7. Discuss the clinical significance of the appearance of the nails. 8. How is acne treated? 15
Skin Color Genetic Factors varying amounts of melanin varying size of melanin granules albinos lack melanin Environmental Factors sunlight UV light from sunlamps X rays darkens melanin Physiological Factors dilation of dermal blood vessels-overheated, embarrassed or using alcohol constriction of dermal blood vessels- temp. drop, frightened accumulation of caroteneyellow color jaundice- liver malfunctionyellow color 16
Healing of Cuts 17
Healing of Burns First degree burn superficial partial-thickness- sunburn Second degree burn deep partial-thickness, blisters Third degree burn full-thickness autograft - from ones own skin homograft - from person to person various skin substitutes- amniotic membrane, silicone, polyurethane or nylon 18
Rule of Nines 19
Life Span Changes Skin becomes scaly Age spots appear Epidermis thins Dermis becomes reduced Loss of fat Wrinkling Sagging Sebaceous glands secrete less oil Melanin production slows Hair thins Number of hair follicles decrease Nail growth becomes impaired Sensory receptors decline Body temperature unable to be controlled Diminished ability to activate Vitamin D 20
Notebook 1. Describe the genetic and environmental factors that influence skin color. 2. What conditions can produce a yellow color in the skin? 3. Describe the process of healing in a shallow break in the skin. 4. Describe the injury and healing process in a superficialthickness burn. 5. List some changes that occur as the skin ages. 21
Notebook Critical Thinking: # 3, 4, 6, 7, 8,9 Chapter Review # 1, 11, 13, 14, 16, 20, 22, 25, 26 22
Clinical Application Acne Vulgaris most common skin disorder sebum and epithelial cells clog glands produces whitheads and blackheads (comedones) anaerobic bacteria trigger inflamation (pimple) largely hormonally induced androgens stimulate sebum prodiction treatments include antibiotics, topical creams, birth control pills 23