Is it appropriate to offer physiology class in the third grade of primary school?

It is appropriate to offer physiology classes in the third grade of primary school, because we should pay attention to children's physiology education. The third grade is the child's developmental period, and it is more appropriate to carry out physiological education at this time. Nowadays, children develop earlier and have more knowledge about the Internet and all aspects. If you don't start classes early, it's easy to delay the healthy growth of children.