UV Damage and Repair Flashcards
What time of day is the peak sunburn/suntan potential?
10-3
Which type of UV ray produces DNA damage?
Both UVA and UVB
Which type of UV ray produces a sunburn and eye problems?
UVB
Which type of UV ray produces premature aging, loose skin, wrinkles, and dark patches?
UVA
Which type of UV ray penetrates deeper into the skin?
UVA. UVA reaches into the dermis close to the subcu fat, UVB primarily affects the epidermis
What does SPF stand for?
Sun Protective Factor
What does SPF not account for?
UVA rays. It only refers to the prolonged burning factor against UVB rays, not UVA rays
How does UVR lead to inflammation?
It causes the release of primary and secondary cytokines that cause inflammation. It also causes the release of histamine from mast cells.
What relationship is there between UVR and Langerhans cells?
UVR damages the Langerhans cells, which inhibits T cells from being activated, resulting in immunosuppression
What role does sunlight play in Vitamin D metabolism?
UVB converts 7-dehydrocholesterol to Pre-D3 which is then converted to D3 and joins circulation where the liver/kidney activate it into active Vitamin D
What are the 2 sources of D3?
It’s metabolized through UVB & 7-dehydrocholesterol or is provided through the diet
What are the 4 major skin defenses against UVR?
DNA Repair, Apoptosis of cells with DNA damage, Defenses against reactive oxygen, melanin
What family is highly involved in DNA repair from UVR?
The XP family (Xeroderma Pigmentosum family)
What do the melanocytes pass on to the keratinocytes?
Melanosomes (which contain/produce melanin)
What is a negative byproduct of melanin production?
Reactive oxygen species
