The relatively constant internal environment in the body is

bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.

answer; the code in musculoskeletal system subsection is associated with deep tissue possibly to the bone;

explanation:

the sun shines white and black light to our planet. the white light has all the colors in it. in our upper atmosphere, we have dust particles and oxygen molecules. the white light meaning all of the colors in a rainbow shines through the upper levels of the atmopshere and the blue light scatters across the entire planet. that is why our sky is blue.