Respiratory Organs

Step 1: Role of Ghrelin.
Ghrelin, often referred to as the "hunger hormone," is produced in the stomach and plays a key role in stimulating appetite by sending hunger signals to the brain. Step 2: Other Hormones.
Insulin helps regulate blood sugar levels and is not involved in hunger signaling. Leptin signals satiety or fullness, reducing hunger. Adrenaline is involved in the body's fight or flight response, not in hunger regulation. Step 3: Conclusion.
Thus, ghrelin in the forebrain and vagus nerve plays an important role in carrying signals of hunger to the brain.

1. Hunger pangs and glucose:
Hunger pangs occur when blood glucose levels drop. The body signals the brain that it needs food to restore glucose levels, which is why we feel the urge to eat. 2. Blood glucose levels:
Glucose is the body's primary energy source, and low levels can lead to feelings of hunger. After eating, glucose levels rise, and hunger typically subsides.