Tanning Beds

This past week we learned about light damage to the skin. There are two types of ultraviolet light (UVA AND UVB). Even when the sun is not shining, UVA light is still present. It is very powerful, with a wavelength of 320-400 nm. UVA light can even go through some clothing. When a person goes into a tanning bed before the age of 30, they are increasing their chance of getting skin cancer by 75%. This type of UV light is also what is responsible for signs of aging.
UVB light is the type of UV light that causes sunburns. The strength of this light is stronger in the summer and weaker in the winter. UVB light is the type of light that causes most skin cancers.

Since I use indoor tanning beds on a regular basis, I looked up an article on how harmful they really are. According to the article, there are about 30 million people that use tanning beds. Many people believe there are not enough regulations in place concerning tanning beds and that there should be more. This year, there will be about 70,000 new cases of melanoma diagnosed (Reuters 2011). I feel as though tanning beds are kind of like cigarettes. People know how bad smoking is for them, and that cigarettes causes lung cancer, yet they still do it. People know tanning causes skin cancer, yet they still use indoor tanning beds.

Link: http://www.msnbc.msn.com/id/45656187/ns/health-cancer/t/tanning-beds-may-raise-common-skin-cancer-risk-percent/

Cellular Aging and the Integumentary System

It has been interesting to learn about what actually happens to cells as they begin to age. The plasma membrane encounters structural changes. For example, the membrane has less fluidity and this is due to an increase in saturated fats. In the calcium pump, transporters slow down which causes there to be too much calcium in the blood, and not enough in the cell. In the nucleus, there is an increase in DNA damage, a decrease in DNA repair processes which leads to errors in proteins being synthesized, and changes in chromatin. With age, the chromatin becomes more condensed, there is less access for repair enzymes, and there is a decrease in RNA synthesis. There is something in the cytoplasm that inhibits DNA syntheses in older cells. Autophagy is the process used to destroy damaged organelles. Proteins can be broken down by entering a proteosome where it is broken down into amino acids and then released. Finally, in the mitochondria, there is a decrease in the number of post mitotic cells which causes the source of metabolic energy to decrease.

So far, I find the Integumentary System to be very interesting. Part of this may be that all of the material is new to me; but there is just so much going on in our skin that I was unaware of. I would have never thought as our skin to be an organ but it is actually the biggest organ of the body which is composed of all four cell types. The average person's skin in 22 square feet, 1-2 mm thick, and weighs 10 pounds. There are two major layers: the epidermis and the dermis. There are five layers of the epidermis and they include, the Stratum Basale, the Stratum Spinosum, the Stratum Granulosum, the Stratum Lucidum, and the Stratum Corneum.

I decided to find an article that talks about autophagy because I find it to be an amazing process. The article states that autophagy is an homeostatic process where cells break themselves down (Levine et al, 2011). This is an important process with regards to immunity and inflammation. Autophagy occurs because of nutrient deprivation or metabolic stress (Levine et al, 2011). The link to this article is: http://www.nature.com/nature/journal/v469/n7330/full/nature09782.html