Collagen is a structural protein found in different connective tissues of the body such as bones, cartilage, tendons, ligaments, skin e.t.c. it is the most abundant protein in mammals. It comprises of various amino acids that are join together to form triple helix of fibrils. Collagen is found in hair and other things because it is found in skin follicles that surrond the hair. The collagens that surrond the hair bulb increases the amount of hair and thicken it.
I believe the answer you are looking for has to do with cells, they are the basic building block of life and are the smallest life that can support itself.
<em>The faster moving air from the fan displaces the warmer air that is in direct contact with our skin. This enhances the rate of convective heat transfer, which means we feel cooler.</em>
