That element is <span>Nitrogen.</span>
The photoreceptors would be your eyes, chemoreceptors skin, olfactory for nose and mechanoreceptors for obviously tongue hope this helps.
Exercise is the primary advice the coaches give to the athletes if they get a cold or any other infection. The main reason behind this advice is the fact that exercising strengthens the immunity of a person. When a person has an infection, the strengthening of the immune system will help his body to efficiently fight against the infectious pathogens. The blood circulation is increased which is involved in the enhancement of the acute immunity of the person.
There are so many examples for that in different areas, like TPT1 experiment carried out in our lab recently.Here's one link: http://www.alfa-chemistry.com/tpt1-cas-167218-46-4-item-290583.htm