Answer:
pineal
Step-by-step explanation:
The pineal gland is a small structure located at the posterior end of the third ventricle, above the diencephalon roof, connected to it by small branches, right in the center of the human brain.
There is controversy about the functions attributed to the pineal gland. However, it is known to be fundamental in contributing to various cycles considered vital in the body, such as the sleep cycle and the regulation of sexual and reproductive efforts and circadian cycles in general.
Therefore, if exposure to blue light can affect human circadian rhythms. This suggests that blue light disturbs the function of the pineal gland.