Answer: Nervous system.
Step-by-step explanation:
Nervous system is the system in the body that consists of nerves,cells that coordinates action and sensory information and transmit nerve impulses between the body and the brain. In the body, Ghrelin is an hormone or chemical produced in the stomach. This stimulate hunger by acting on neurons in the hypothalamus which make the nerve cells that cause hunger to increase in their activity and reduce hunger inhibiting cells. The hypothalamus produce two proteins that cause hunger: neuropeptide Y (NPY) and agouti-related peptide (AGRP. This create a signals and it is send to the brain. The brain interprete it as hunger and send the signal to the hypothalamus which then influence eating behavior.