Which hormone is released by the gastrointestinal tract when the stomach is empty to stimulate hunger?

Ghrelin is the hormone released by the gastrointestinal tract when the stomach is empty, and it plays a crucial role in stimulating hunger. This hormone is often referred to as the "hunger hormone" because its levels rise prior to meals and decrease after eating. Ghrelin acts on the hypothalamus, specifically at areas involved in appetite regulation, signaling the brain to induce the sensation of hunger and encourage food intake.

This is crucial for maintaining energy balance, as it helps to ensure that the body receives adequate nutrition when energy stores are low. Ghrelin is produced mainly in the stomach, although smaller amounts can be found elsewhere in the gastrointestinal tract. Its effect on hunger is a key component in understanding eating behavior and weight regulation, as well as its potential implications in conditions like obesity or anorexia.

In contrast, other hormones mentioned have different roles in the body. For example, prolactin primarily regulates lactation and has no direct relation to hunger. Leptin, which is primarily produced by adipose tissue, signals satiety and reduces appetite. Follicle-stimulating hormone is involved in the regulation of reproductive processes and does not influence hunger. Hence, the role of ghrelin is distinctive in prompting the feeling of hunger under