I believe this would be the cerebellum. This part of the brain is used for motor control like moving the fingers say and cognitive functions (to do with thinking) and also can affect the feelings of pain and pleasure.
Well because death by starvation would be far more agonizing than death by predators. Starving to death would last longer and the death would be more excruciating.
Pepsinogen, an inactive zymogen, is secreted into gastric juice from both mucous cells and chief cells. Once secreted, pepsinogen is activated by stomach acid into the active protease pepsin, which is largely responsible for the stomach's ability to initiate digestion of proteins.