Skin Flashcards
What are the main layers of the skin?
**epidermis = **keratinocytes and melanocytes
**dermis = **connective tissue (BV, nerves hair follicles)
**subcutis = **fat tissue
Give clinical examples of a macule, patch, papule, vesicle, pustule, plaque, ulcer, and nodule.
macule = freckle
patch = measles
papule = eczema
vesicle = herpes
pustule = impetigo
plaque = psoriasis?
ulcer = chancre
nodule = ?
What is icthyosis?
A congenital thickening of the skin, forming numerous large scales (squames)
What is albinism?
Generalized hypopigmentation caused by inborn error of metabolism. Individual lacks enzyme essential for the synthesis of melanin (from aa tyrosine and phenylalanine).
What is epidermolysis bullosa?
Term used for several congenital skin disorders, all characterized by the formation of blisters on rubbing of the skin or minor trauma (usually on palms and soles)
Explain the effects of mechanical trauma on the skin and subQ tissues.
Blunt trauma: usually causes contusion, bleeding into skin and soft tissues.
Laceration: disruption of skin and underlying soft tissue.
What are the differences between first-degree, second-degree, and third degree burns?
1st: erythema and swelling, spotty, single cell necrosis and edema.
2nd: epidermal blisters (spares follicles)
3rd: massive necrosis of entire epidermis and dermis
Compare immersion foot and frostbite.
Immersion foot = exposure to nonfreezing cold and moist environment. small blood vesses, stunned by cold become permanently dilated and unable to regulate local blood flow. **venous stagnation >> necrosis >> blisters and ulcers
frostbite = exposure to subfreezing temperature. blotchy, red and swollen with reheating >> gangrene
Describe an “electric mark” on the skin.
Passage of electricity generates hear, which burns the tissues >> linear marks
Compare the effects of acute and chronic sun exposure.
acute = hyperemia, 1st or 2nd degree thermal injury
chronic = skin becomes more birttle, less elastic, develops wrinkles, resist injury less efficiently, skin cancer
Describe and explain the pathogenesis of impetigo, folliculitis, furuncle, and carbuncle.
Impetigo: highly contagious, heals without scars, strep or staph aureusI, honey colored scab, superficial
Folliculitis: limited to hair follicles
Furuncle: bacteria invades hair shaft and extends into perifollicular tissue
Carbuncle: enlarges to include several hair follicles
Compare superficial dermatophytosis with deep fungal infections.
Superficial dermatophytosis >> live in surface area, causing no inflammation of underlying skin
Deep fungal infections >> cause large destructive lesions and tumor like lesions
List viruses that infect skin.
measles, chickenpos, herpes zoster, herpes labialis, HPV
Describe insect bites.
**itchy, maculopapular skin lesion with a red dot in the center. **
What is scabies?
Caused by a mite. Creates burrows in the superfiical layers of the epidermis. Maculopapular eruptions evolve in reponse ot the bite, feces, or ova