Final answer:
The stomach produces the hormone ghrelin to signal the brain to start eating. Ghrelin stimulates appetite and increases hunger sensations when the stomach is empty, while the hormones released when the stomach is full decrease appetite.
Step-by-step explanation:
The stomach produces a hormone called ghrelin to signal the brain to start eating. Ghrelin is produced by the cells in the stomach lining and is released when the stomach is empty.
When ghrelin reaches the brain, it stimulates the appetite and increases hunger sensations, motivating a person to eat. Once food is consumed, the stomach stretches and releases hormones that signal to the brain that the stomach is full, leading to a decrease in appetite.
Overall, ghrelin plays a crucial role in regulating the hunger and satiety signals between the stomach and the brain.