suprachiasmatic nucleus; SCN
A tiny region in the brain's hypothalamus, directly above the optic chiasm, that acts as the master circadian clock.
The suprachiasmatic nucleus is known as the center of the biological clock.
Light stimuli are transmitted from the retina to the suprachiasmatic nucleus.
Compound of 視交叉 (optic chiasm) + 上 (above) + 核 (nucleus), directly describing its anatomical location.