Integumentary System Ch. 5 Part 2
Skin Physiology Vitamin D Deficiency – Skin needs UV rays to initiate production of vitamin D – Vitamin D is turned into calcitrol which helps in absorption of calcium in intestines – Lack of vitamin D – leads to rickets or osteomalacia
Skin Physiology Regulates body temperature – Done with sweat glands (sudoriferous) – Water/salt comes to surface – As water evaporates, heat is taken away with the water – Eccrine – function when hot – Apocrine – function during stressful times
Skin Physiology Oil Glands (sebaceous) – Released onto shaft of hair – Goes to surface of skin to: Protect, lubricate, and waterproof skin Problem – Drainage becomes blocked – pimples – Production of sebum (oil) is controlled by sex hormones
Skin Physiology Ceruminous (wax) glands – Secrete wax into ear canal – Functions: Insect repellant Keeps eardrum flexible – Problem Excess ear wax can interfere with hearing
Hair
Hair and Hormones Hisutism – Higher than normal levels of androgen (hormone) cause excessive hair on lip, chin, chest, thighs, abdomen Male-pattern baldness – Androgen inhibits hair growth for genetically predisposed males
Skin Wound Healing Epidermal Wound Healing – near the surface (abrasion – scrape), 1 st /2 nd degree burns – Detached, basal cells migrate till they meet each other – Cell division fills in the space – No bleeding – Epidermal growth factor (EGF) – protein hormone that stimulates growth of dermal cells and fibroblasts
Epidermal Wound Healing
Skin Wound Healing Dermal (deep) Wound Healing 4 phases – Inflammatory phase – Migratory phase – Proliferative phase – Maturation phase Scar formation
DWH - Phases Inflammatory – clot forms (platelets) – WBC arrive for defense Migratory – clot becomes a scab by fibroblast production – Epithelial cells begin to regrow
DWH - Phases Proliferative – Epithelial cells grow beneath scab – Collagen fibers deposited – Tissue is reformed Maturation – Sloughing off of scab – Collagen fibers organize
DWH – What would I see between these 2 phases?