Hormones come in three categories. blank circulate in the blood and act at sites distant from their origin; blank pass through ducts; and blank act on their local tissue environment.

paracrines
exocrines
endocrines

ENDOCRINES circulate in the blood and act at sites distant from their origin;

EXOCRINES pass through ducts;

and PARACRINES act on their local tissue environment.

Explanation:

Exocrines are known for producing external secretions that are released through a duct, usually into the digestive system or the skin

Endocrine are known for producing internal secretions called HORMONES that are transported around the body by the bloodstream. They are also called ductless glands.

Paracrines are known for producing hormones that act on his immediate location or producing gland

bacteria could be both, harmful and to us. harmful bacteria could make us sick and probably even by getting the chances of getting a disease, but good bacteria fight it off with your immune system. there is always bacteria everywhere we go. we need to make sure to wash our hands after using the restroom, before eating, after eating, after petting an animal too. so you see, bacteria is everywhere and is harmful or . i hope this . : ) : ) : )