From the Guidelines
There is no such thing as an orexigenic gland in human anatomy or physiology. The term "orexigenic" refers to something that stimulates appetite or hunger, but it's not associated with a specific gland in the body. Instead, appetite regulation involves complex interactions between the hypothalamus in the brain, hormones like ghrelin (produced primarily by the stomach) and leptin (produced by fat cells), and various neurotransmitters. These systems work together to control hunger and satiety signals. If you're interested in structures that influence appetite, you might want to look into the hypothalamus, which contains neurons that respond to and regulate hunger signals, or the endocrine organs that produce appetite-regulating hormones like the stomach (ghrelin) or adipose tissue (leptin).
Some studies have investigated the use of orexigenic drugs, such as megestrol acetate, to stimulate appetite in patients with cancer or dementia 1, 2. However, the evidence for their effectiveness is limited and inconclusive, particularly in patients with dementia 2. In fact, the most recent guideline on nutrition and hydration in dementia recommends that drugs that stimulate appetite should not be offered to promote food intake in persons with dementia 2. The complex interactions between the hypothalamus, hormones, and neurotransmitters that regulate appetite make it unlikely that a single "orexigenic gland" exists in the body. Key factors that influence appetite include:
- The hypothalamus, which contains neurons that respond to and regulate hunger signals
- The stomach, which produces ghrelin, a hormone that stimulates appetite
- Adipose tissue, which produces leptin, a hormone that suppresses appetite
- Various neurotransmitters that transmit hunger and satiety signals in the brain. Overall, the regulation of appetite is a complex process that involves multiple systems and organs, and there is no single "orexigenic gland" that controls it.