The example of the endocrine system directly interacting with the circulatory system is: The hormone adrenaline causes an increase in heart rate.
Adrenaline (also known as epinephrine) is a hormone released by the adrenal glands in response to stress or danger (the "fight or flight" response). When released into the bloodstream, adrenaline increases heart rate, which enhances blood flow to muscles and vital organs, demonstrating a clear interaction between the endocrine and circulatory systems.