The is the key organin the carculatory system

How do the uv rays cause damage?   what exactly causes the skin to burn;   can you be more specific about this mechanism?   3. how do photosensitive medications increase a person's sensitivity to sunlight and therefore increase their risk of getting burned?     what kind of medications can increase photo-sensitivity, can you think of some examples?

Lifestyle diseases are caused by a combination of

What is the most important issue facing healthcare industry? in a well- developed paragraph, describe the issue and discuss why you think it’s important.