Final answer:
The endocrine system works with the nervous system to influence heart rate by releasing hormones such as adrenaline.
Step-by-step explanation:
The endocrine system works with the nervous system to influence your heart rate. The endocrine system secretes hormones into the blood that travel to body cells and influence their activities. One example of this is the hormone adrenaline, which is released by the adrenal glands in response to stress or danger. Adrenaline increases heart rate as part of the fight-or-flight response.