Endocrine hormones travel throughout the body in the blood, and hormones are the chemical messengers of the body's endocrine system. Given these facts, what travels throughout the body in the blood among the following options:
- chemical messengers
 - carbon monoxide
 - Veins and arteries.
 - bacterial messengers
 - density
 - kinetic energy
 - electromagnetic energy
 - matter vibrating


 

 chemical messengers        