Final answer:
Hormones like leptin and insulin are the main biochemical regulators that decrease appetite and signal satiety to the brain, which reduces hunger. Neurotransmitters like serotonin and dopamine also play a role in regulating appetite.
Step-by-step explanation:
Biochemical regulators that decrease appetite and hunger primarily include hormones such as leptin and insulin. Leptin is a hormone produced by fat cells that signals satiety to the brain, thereby reducing the urge to eat. Insulin, secreted by the pancreas in response to high blood glucose levels, also has a role in signaling fullness and satiety, contributing to the cessation of eating. Other physiological mechanisms involve the pancreas and liver sending signals when blood glucose levels are high, as well as the GI tract providing satiety signals after the passage of food.
Furthermore, neurotransmitters like serotonin and dopamine play a role in appetite regulation, where serotonin has an inhibitory effect on eating and dopamine regulates the rewarding property of food. Imbalances in these neurotransmitters can affect appetite and eating behaviors. It's also noted that ghrelin, though not a satiety hormone, is important for understanding appetite as it has the opposite effect of leptin and stimulates hunger when produced by the stomach and small intestine.