Question

________ are like a messaging system that delivers instructions via the bloodstream to stimulate action. *

pituitary
metabolism
hormones
cells

Answer 1

this is i called hormones

Answer 2

Hormones are like a messaging system that delivers instructions via the bloodstream to stimulate action.

Step-by-step explanation:

Hormones fit this description to a T. The job of hormones are like messengers, delivering messages that exert an action that responds downstream. They are carried by the bloodstream to different cells in the body.

Hope this helps :)