Musculoskeletal System. When the body is stressed, muscles tense up. Muscle tension is almost a reflex reaction to stress — the body's way of guarding against injury and pain. With sudden onset stress, the muscles tense up all at once, and then release their tension when the stress passes.
The USDA Center for Nutrition Policy and Promotion.
They created food pyramids and circles as well.
Hope this helps!
None really unless you are talking about an animal
The process is Cell Growth.
