Hunger and Appetite Hormones

• Hormones play a crucial role in regulating hunger, fullness, and satiety by interacting with specific brain centers, particularly the hypothalamus, which integrates these signals to manage food intake and energy balance effectively.
• Genetic defects can disrupt hormone targeting, causing diminished satiety signals and potential weight gain.
• Appetite control is regulated by hormones like leptin, CCK, ghrelin, and PPY.
• Hormone deficiencies can negatively impact energy metabolism.

Leptin

• Produced by adipose cells, decreases appetite upon release.
• Signals the brain that enough food has been consumed, inhibiting appetite.
• Informs the brain of caloric intake and energy stores.

Ghrelin

• Produced primarily by the stomach, with smaller amounts from the small intestine, pancreas, and brain.
• It is the opposite of leptin, increasing appetite, food intake, and fat storage.
• Stimulates fat deposition and growth hormone release, leading to increased hunger and fat storage.

CCK (Cholecystokinin)

• Released in the gastrointestinal system to stimulate fat and protein digestion.
• Secreted by cells of the upper small intestine.
• Released when amino acids or fatty acids enter the stomach or small intestines.
• Stimulates gallbladder contraction and bile release into the intestine, aiding fat and protein breakdown.

NPY (Neuropeptide Y)

• Neuropeptide hormone linked to the autonomic nervous system.
• Neuropeptides are small protein-like molecules for neuron communication.
• Influences brain and body activity.
• Specialized hormone from the hypothalamus.
• Stimulates the sympathetic nervous system, which increases appetite and fat storage.

Insulin and Glucose

• Insulin is produced by the pancreas when blood glucose levels are high.
• It promotes glucose uptake for fuel or storage as glycogen.
• Insulin prevents blood sugar from becoming too high (hyperglycemia).
• Insulin increases glucose uptake in peripheral tissue (e.g., skeletal muscle) and decreases glucose production by the liver.

Glucagon

• Released when blood sugar levels decrease below a certain threshold.
• Stimulates glycogen breakdown in the liver, releasing glucose into the bloodstream for fuel.

Hormones play a crucial role in regulating hunger, fullness, and satiety through specific brain centers. Hormones like leptin, ghrelin and CCK regulate appetite control. Deficiencies in these hormones can negatively impact energy metabolism.