Vase is doing experiment , lab activities in his classroom , He is tired due to hungry. How hungry feeling occurs ? How will one know ?

Explanation

1) Levels of different substances are generally maintained in the blood mainly by our digestive system.
2) One of the major substance is glucose . When its levels in the blood fall , we get hunger pangs in stomach.
3) Ghrelin is secreted from the certain cells in the wall of the stomach
4) Hunger contractions (hunger pangs ) start to occur in the stomach de to the secretion of Ghrelin hormone.
5) Increase in ghrelin levels results in sensation of hunger and motivation to consume food .