What happens to the respiratory system as it ages?

What are your thoughts on nonhuman trials? do you feel that testing should be done on animals? what are the advantages and disadvantages with nonhuman trails?

As you sit in the library with your friend studying for your weekly quiz on the integumentary system, you come upon an article about the hazards of prolonged exposure to the sun's rays. your curious nature leads you to research the subject further. you're fascinated to learn that minimal exposure to the sun allows you skin to manufacture vitamin d, which is important to maintain homeostasis. you also read that although sunscreen can protect you from the ultraviolet (uv) rays of the sun, some medications can actually increase a person's sensitivity to the sunlight.

Diseases may arise when proteins fail to fold correctly in their last stages of processing and/or are directed towards the lysosome rather than towards the cell membrane. cystic fibrosis is an example of this type of disease. in cystic fibrosis, a functional ion channel is sent to the lysosome for destruction rather than being sent to the plasma membrane. given this observation, the cellular component that is most likely the cause of the disease is the