Skin, Hair and Nails Flashcards
Skin Facts
Largest organ in the body, skin conditions as part of chronic health conditions (ex diabetes and obesity) weights appx. 6 lbs protective shield regulates body temp stores water, fat, vit D pain receptors
Skin as an External Manifestation of Disease
- genetic syndromes and congenital disorders
- endocrine / metabolic disorders
- systemic diseases
- infections
3 sublayers of epidermis
stratum corneum
cellular stratum
basal layer
stratum corneum
horny layer
continually shedding dead keratinocytes. keratin protein formed from dead cells protects outer skin surface
cellular stratum
contains melanocytes, pigment and living keratinocytes (squamous cells)
basal layer of skin
inner layer of epidermis. contains basal cells that continually divide, forming new keratinocytes. migrate upward over 4 weeks
dermis
middle layer of skin. contains blood vessels, lymph vessels, hair follicles, sweat glands, sensory and autonomic motor nerves.
held together by collagen made by fibroblasts.
subcutis
deepest layer of skin. network of collagen an fat. conserves body heat. shock absorber.
eccrine glands
sweat glands, open onto surface of skin, evaporative cooling
apocrine glands
under arms and groin. secrete little or no odors alone, but bacteria accumulated in nearby hair can result in characteristic odors
3 segments of hair follicle
bulb, isthmus, infundibulum
Bulb and suprabulb
base of follicle to the insertion of the erector pili
isthmus
short section of hair follicle that extends from insertion of erector pili to entrance of sebaceous gland duct
ifundibulum
upper segment of hair follicle. entrance of sebaceous gland duct to follicular orifice.
3 phases of follicular life cycle
anagen phase
catagen phase
telogen phase
…ACT!
anagen phase
active growth, 3-4 years, 84% of scalp follicles are in anagen
catagen phase
follicular regression. 2-3 weeks. 1-2% of follicles.
telogen phase
resting period. 3 months. 10-15% of hair follicles.
nail facts
keratinized structure. 0.1mm growth per day 6 months to regrow dominant hand grows faster men faster than women
anatomy of the nail
hyponychium, nail plate, lanula, eponychium, dorsal root
Physical Exam of Skin
color, moistness, temp, texture, turgor, mucous membranes
Examining dermatological lesions
location and distribution, lesion type (primary vs. secondary), lesion arrangement, cutaneous color changes)
Skin lesion distribution
sun exposed vs. covered by clothing flexural vs. extensor stocking an glove face shoulders back = acne truncal
primary lesion definition
skin lesion as it first appears
types of primary lesions
macule (patch) papule (plaque)
wheals
vesicle (bullae)
pustules
macule
circumscribed flat discoloration
papule
elevated solid lesion up to 0.5cm
plaques
circumscribed elevated superficial solid lesion geater than 0.5cm, confluence of papules
wheals
firm edamatous plaque resulting from infiltration of the dermis with fluid (hives)
vesicle and bullae
circumscribed collection of free fluid 0.5cm
ex. chicken pox, herpes
pustules
circumscribed collection of leukocytes and free fluid ex. follicuitis, impetigo
secondary lesion
transformed primary lesions
types of secondary lesions
scales -excess dead epidermal cells
atrophy -depression in the skin resulting in thinning
erosion
fissure
arrangement of skin lesions
annular = circle arcuate = curve circinate = C shaped confluent = blotch discoid = disk grouped= grape clusters iris = circle with nucleus reticulated = spider web serpignous = snake like telangiectatic = looks like nerve cells
nail exam
shape
color
abnormalities: pigment, pitting (psoriasis), spooning (Fe deficiency), clubbing (lung diseases)
hair exam
quantity and distribution
color
texture
presence of abnormalities
diagnostic techniques to evaluate skin hair and nail disorders
woods light - fungus
diascopy - using glass to depress and blanche skin
direct microscopy - observing a skin scraping
biopsy - punch, incisional, excisional, shave
patch and prick - allergy testing
HPDP - Skin Cancer
SCC and BCC are most commonly occuring skin cancers
Malignant Melanoma is most rapidly increasing malignancy
Skin cancer diagnoses are more than all other cancers combined