Question
A three-and-a-half-year-old boy has experienced a change from having single eyelids to double eyelids, followed by a cold and fever soon after. Is this change necessarily related to illness? Why does this pattern always occur, and what is the underlying principle behind it?
Answer
Lack of appetite refers to a lack of desire for food, which is severe when called anorexia. The appetite center is located in the hypothalamus, which has extensive connections with the cerebral cortex. There are two regulatory centers for feeding in the hypothalamus: one is the satiety center, located in the ventromedial nucleus, and animal experiments show that destroying this center leads to hyperphagia and increased food intake; the other is the orexin center, located in the ventrolateral nucleus, and destroying this center causes animals to lose appetite and refuse to eat. These two centers regulate each other to control feeding. As for the association between changes in eyelids and feverish colds…