HISTOLOGY
INTEGUMENTARY SYSTEM SKIN
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
TRUE
|
|
|
FALSE
|
|
|
Either A or B
|
|
|
None of the above
|
Detailed explanation-1: -Melanin protects skin from the sun’s ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken. The tan fades when new cells move to the surface and the tanned cells are sloughed off.
Detailed explanation-2: -Photoprotective Role of Melanin The shielding effect of melanin, especially eumelanin, is achieved by its ability to serve as a physical barrier that scatters UVR, and as an absorbent filter that reduces the penetration of UV through the epidermis (68).
Detailed explanation-3: -Melanin is different. Instead of becoming very reactive when hit by UV light, melanin releases the extra energy as heat; it reacts less than 1 out of every 1000 times it becomes excited. This allows melanin to protect more sensitive molecules, like DNA, from UV exposure.