Uploaded August 2024 | Updated September 2026, 1 week ago
Our bodies sync our most basic functions with the external environment’s timescale via circadian rhythms. Those rhythms are why many people cycle through a routine of core tasks like waking up, eating meals, and, finally, heading to bed around the same time each day. Circadian rhythms are informed by light — mostly sunlight, though artificial light, too, can influence them.
Specialized cells in our eyes’ retinas transmit information about light to superchiasmatic nuclei, or SCN, in the hypothalamus. From there, the SCN sends timing cues to various systems in the body. Circadian dysrhythmia, or jetlag, can occur when light input doesn’t match Earth’s 24-hour solar cycle, and it causes a range of consequences for people’s moods and cognition.
This is a video from the 2024 Brain Awareness Video Contest: brainfacts.org/for-educators/programs-and-events/brain-awareness-video-contest
Created by Tammy Strickland.
Our bodies sync our most basic functions with the external environment’s timescale via circadian rhythms. Those rhythms are why many people cycle through a routine of core tasks like waking up, eating meals, and, finally, heading to bed around the same time each day. Circadian rhythms are informed by light — mostly sunlight, though artificial light, too, can influence them.
Specialized cells in our eyes’ retinas transmit information about light to superchiasmatic nuclei, or SCN, in the hypothalamus. From there, the SCN sends timing cues to various systems in the body. Circadian dysrhythmia, or jetlag, can occur when light input doesn’t match Earth’s 24-hour solar cycle, and it causes a range of consequences for people’s moods and cognition.
This is a video from the 2024 Brain Awareness Video Contest: brainfacts.org/for-educators/programs-and-events/brain-awareness-video-contest
Created by Tammy Strickland.
