Answer: The given is False.
Internal sleep and wake cycles are controlled by circadian biological clock of the body. It is located in the brain. The biological clock produces circadian rhythms in the body which are mental, physical, and behavioral responses of body which follow an everyday cycle.
A tiny region ( Suprachiasmatic nucleus, SCN ) in hypothalamus of the brain controls the circadian rhythms. It does this by generating neuronal and hormonal activities.
Thus, the statement that adrenal glands control internal sleep and waking cycles is False.
