Dermatology - intro Flashcards
how large is skin
a vital organ, one of the largest with a surface area of about 1.8m2 or 1.5-2.0
what is the primary role of the epidermis?
protect from the environment and perform critical barrier function
keeps water and other vital substances in and keep foreign substances out
what is the primary role of the dermis?
connective tissue that provides resiliency and support to structures or appendages such as sweat glands, sebaceous glands, and hair and nail
where is the subcutaneous dermis?
under the dermis
what are the layers of the epidermis?
stratum corneum
stratum granulosum
stratum spinosum
stratum basale
whats the horny layer?
startum corneum
whats the granula layer
stratum granulosome
whats the prickle cell layer?
stratum spinosum
what’s the basale layer
stratum basale
what is the function of keratinocytes
= skin cells
produce keratin and produce other physical protective barriers
what is the function of melanocytes
provide melanin and UV protection
what is the function of a hydrolipid film on the skin surface?
provides a permeability barrier
what does the dermis house?
collagen and elastin to provide support for structures
what does the skin do
-protection the skin against injury, physical agents and UV radiation
-regulates body temperature
-prevents dehydration thus helping to maintain fluid balance
-acts as a sense organs (touch, pain, heat, cold)
- acts as a post for immune surveliance
- has a role in vitamin D production and absorption
skin hydration - what is considered hydrated vs not?
normally 10-20%
if drops below 10% then we have a problem
what happens when the skin is dehydrated?
the stratum corneum becomes brittle and cracks
- this can lead to the penetration of irritants
- allows for mild inflammation and impaired cell maturation
- reuslts in cahpping
how does the barrier regenerate?
starts to regenerate within 24 hours of skin damage
- forms a temporary barrier of parakeratotic cells and dried exudate
- horny layer reforms over 12-25 days
what factors contribute to dry skin? (9)
-low ambient humidty
- extremes temperatures
- overuse of surface active agents (soaps)
- physical trauma
- chemical irritants/trauma
- aging
- genetic abnormallities in keratinocyte composition or function
- other medical conditions
- medications (vitamin A, systemic retinoids, anticholingeric, niacin, come chemo Rxs)
Hydration - what are some basics of skin care?
- adequate fluid intake
- diet
- sleep
- exercises
- after showing and light towel drying apply moisturizer within 3 minutes when skin is still dry
- moisture and use an oil free moisturer if acne prone
How often should we cleans? what is a risk of cleaning too muc?
we should wash face with mild sopa and water a max of 2 times a day (espcecially if you have probkem skin)
too muhc cleasning can lead to dry skin
what is the concern of bathing and showering?
prolonged baths or showers can lead to dehydration
bath are more hydratining especillay if we have emulsifying agents
What are some additional points to keep in mind about skin hydration?
- astringent and aclohol products should be avpided or caustiously used
- soapless cleansers are preferred
- fragrance free products are preefered
- Use sunscreen at least SPF 15, 20 mins before sun exposure and reapply every 2 hours or after swimming or sweating it off
how does aging affect skin hydration?
thinning of the epidermis - fewer active basal cells in the epidermis
slower healing - slower cell turnover
delayed inflammatory reponses - fewer Langerhans cells
reduced tastile sensitivty - reduced pain perception
