Skin Disorders Chapter 8

Key Terms Excoriations Keratin Larvae Lichenification Sebum Use your textbook to define these 9 key terms Albinism Atopic Autoinoculation Denuded Excoriations Keratin Larvae Lichenification Sebum

Skin Diagram Color code the following on the skin diagram Stratum corneum Stratum basale Eccrine (sweat) gland Sebaceous (oil) gland Smooth (arrector pili) muscle Bracket & label the epidermis, dermis, & hypodermis

Hair follicles Lined with stratum basale that produces the hair at the matrix Hair papilla contains capillaries to nourish hair Connected to arrector pili muscle

Arrector pili muscle Smooth muscle Controlled by sympathetic NS – (fight or flight NS) – part of autonomic NS Stimulated by emotion or cold

Sebaceous gland Open into hair follicle Produce sebum (oil) which keeps hair & skin soft and helps with waterproofing Action increases at puberty due to hormone action

Eccrine gland Sudoriferous (sweat) gland - Aka. Merocrine gland Secrete watery sweat for thermoregulation Secreted directly onto skin surface through a duct Activated by heat or emotional stress under SNS control

Apocrine gland Sudoriferous (sweat) gland Secrete viscous organic sweat made of proteins & fatty acids – body odor caused by action of normal bacterial flora Secreted into hair follicle through a duct Activated by heat or emotional stress under SNS control Located primarily in axillary (armpit) & ano-genital regions, some on scalp & facial areas

1st line of defense Provide barrier against pathogen invasion Sebum is slightly acidic & has bactericidal effect Resident flora also deters invaders

Prevention of excessive fluid loss Keratinized epidermis waterproofs skin

Thermoregulation Vasodilation of BV & evaporation of sweat to cool off body Vasoconstriction of BV to keep body warm

Sensory perception Defense against environmental hazards Learning tool Communication of emotions, etc.

Vitamin D synthesis Synthesis of Vitamin D Cholesterol molecules in skin cell membranes is converted by UV rays into inactive Vitamin D Inactive Vitamin D is activated by liver & kidney cells Active Vitamin D allows body to absorb Calcium from stomach into BV. No Vitamin D = No Calcium absorption

Resident/Normal Flora Indigenous (normally reside) in specific places on or in body Helpful in preventing other organisms from colonizing May cause opportunistic infections which may spread

Skin Lesions Go to the following link (also on webpage) http://courses.washington.edu/hubio567/lang/ Make flashcards using information from Table 8-1 on Textbook page 143 Study pictures from link above Not on slide show from webpage Keloid & Comedone pictures

Pruritus: itching sensation Mechanism not fully understood – release of histamine involved – pain receptors mildly stimulated by irritants Scratching may lead to secondary infections & subsequent scar tissue.

Pruritus: itching sensation Diagnostic tests Skin scraping Culturing & staining Direct observation Specific procedures for identification General treatment Antihistamines, glucocorticoids Identification & avoidance of allergens Compresses Removal of any precancerous lesions

Basic Categories of Skin Disorders Inflammatory Infections Tumors

Skin Disorder Charts You will each be creating a Disorder Portfolio subdivided into Body Systems. This will be an ongoing project that you will receive a grade for at the end of each quarter. All information will come from your textbook pages unless your notes state otherwise. You will also have Quizzes (given in Matching or M/C format) over the disorders