You are presented with the question "Where do endocrine glands secrete?" and the following answer choices: 
- plasma
 - Chemical energy
 - Energy.
 - lungs
 - heart
 - Energy
 - alveoli
 - bloodstream

Now knowing that endocrine hormones travel throughout the body in the blood and endocrine glands secrete directly into the blood, choose the best answer.


 

        bloodstream 