Regulation slowly happens but produces long-lasting effects, whereas regulation quickly takes place with short-term effects

Endocrine system regulation slowly happens but produces long-lasting effects, whereas nervous system regulation quickly takes place with short-term effects.

Endocrine system can regulate many things in the body that control the metabolism. The effect shouldn't be instant, but it should be good for long term effect. Nervous system need a much faster reaction because it responsible for "fight or flight" reaction. A slow nervous system will cause the organism caught by predator easier.