Can you suggest any four systems involved in the process of generating hungers

Can you suggest any four systems involved in the process of generating hunger sensation ?
A. Digestive system, Endocrine system, Circulatory system and Nervous system.
Observation of how our taste is affected by the sense of smell.

  1. First close your nose with your fingers.
  2. Pop in some zeera in your mouth and chew it for sometime.
  3. After that chew sounf.
  4. Could you recognise the taste ?
  5. How long it taken to know the taste ?
  6. After sometime wash your mouth and repeat the activity by chewing a piece of an apple followed by a potato (remember to close your nose)