The -- secrets chemical messages that circulate through the blood, and also communicate messages that influence behaviors and many aspects of biological functioning

Answer 1

The answer is: endocrine secrets. The endocrine system is responsible for producing and secreting hormones into the bloodstream, which then travel to various organs and tissues to influence a range of physiological and behavioral processes. Hormones play a key role in regulating growth and development, metabolism, reproduction, mood, stress responses, and many other functions in the body.