UV Radiation and Skin

Question 1

___ radiation is outside the visible light spectrum. ___ wavelength means more energy and more ability to displace ___.

Answer 1

UV
Shorter
Electrons

Question 2

Most important UB radiation types are ___ and ___

Answer 2

UVA
UVB

Question 3

When UV light hits the skin, it can be ___, ___, or ___.

Good radiation absorbers are ___ amino acids, ___ ___, and polymers like ___.

Answer 3

Absorbed
Transmitted
Scattered
Aromatic
Nucleic acids
Melanin

Question 4

UVA has a longer wavelength and therefore scatters ___, and travels ___ into the skin

Answer 4

Less
Deeper

Question 5

Damage only occurs when radiation is ____.

Answer 5

Absorbed

Question 6

Tyrosine is ___ and that’s why it’s part of melanin synthesis.

Answer 6

Aromatic

Question 7

Scale of skin types: Fitzpatrick scale:

Answer 7

Question 8

Sunburn is caused by covalent linking of ____. Kink in the DNA. Phospholipids of the cell membrane produce ___ ___ metabolites leading to dilation of blood vessels, Degranulation of mast cells, and release of cytokines

Answer 8

Pyrimidine
Arachidonic acids

Question 9

1 week after sun burn, ___ of the skin. Melanin actually gets darker. Keratinocytes secrete factors that stimulate melanocytes to produce more melanin

Answer 9

Darkening

Question 10

High UV doses causes blistering and skin ___.

Answer 10

Desquamation

Question 11

Risk of melanoma increased by ___ when tanning bed use is before age 35.

Answer 11

75%

Question 12

Review factors that affect UV dose:

Question 13

UV exposure in the dermis:
causes down regulation of ___, up regulation of _____ produced by dermal fibroblasts, less ___ and more disorganized masses of elastic fibers, melanin is not as effective in protecting the dermis.

Answer 13

Collagen
Metalloproteinases
Elastin

Question 14

___ __ is disorganized masses of elastic fibers

Answer 14

Solar elastosis

Question 15

Why sunscreen?
The nucleotide excision repair system is not perfect. If there is too much damage there is too much to repair. If the Pyrimidine dimer is in a sequence that encodes a tumor suppressor gene…. Like p53…. More harmful

Answer 15

Question 16

UVA is more the culprit for ____ (solar elastosis). UVB is more risk for ____. and riskier for ___.

Answer 16

Dermatoheliosis
Sunburn
Cancer

Question 17

Answer 17

False

Question 18

SPF stands for ___ ___ ___, measures how much UV radiation is required to produce sunburn on protected skin versus the amount of UV radiation required to produce sunburn on unprotected skin. Wearing SPF 30, means it would time 30 times more UV radiation to produce a sunburn

Answer 18

Sun Protection Factor

Question 19

Recommended everyone wear SPF __ and apply every __ hours.

Answer 19

30
2

Question 20

____ ___ sunscreen must protect against UVA and UVB

Answer 20

Broad spectrum

Question 21

Types of sunscreen:
_____ (mineral or inorganic): block or scatter UV using titanium dioxide or zinc oxide
_____ (organic): absorb the UV light and re-emit the energy as heat

Answer 21

Physical
Chemical

Question 22

Positive of UV radiation:
Vitamin D metabolism. We can get it from the ___ but generally not enough. _____ is photochemically transformed in the skin by UVB radiation into pre-vitamin D3 which is isomerized to vitamin D3. Liver and kidneys help.

Answer 22

7-dehydrocholesterol

Question 23

UV effect on immune system:
Keratinocytes have the ability to activate ___ immune responses. Langerhan’s cells bridge the adaptive and innate

Answer 23

Innate

Question 24

After UV exposure, ___ langerhans cells in epidermis, langerhans cells that are ___ in antigen presentation at the spleen, ___ generation of suppressor T lymphocytes thought to be mediated by IL-10 and TNF-alpha.

Decreased ___ immunity and decreased ability to activate ___ immune response

Answer 24

Decreased
Defective
Increased
Local
Adaptive

Question 25

UV allowing carcinogenesis by effecting the immune system:

Answer 25

Question 26

Immunosuppressive medication long term use can result in higher rates of ___ __ __ and __ __ ___.

Answer 26

Basal cell carcinoma
Squamous cell carcinoma

Question 27

Harnessing the immune suppression from UV light:
Lupus sometimes improves with UV light with the right ___.

Answer 27

Wavelength