Suprachiasmatic nucleus facts for kids

Kids Encyclopedia Facts
Circadian rhythm labeled
A variation of an eskinogram showing the influence of light and darkness on circadian rhythms and related physiology and behavior through the SCN in humans

The suprachiasmatic nucleus (SCN), is a small nucleus in the hypothalamus in middle of the brain. It is right on top of the optic chiasma.

It is our "body clock", and controls our daily rhythms by hormones and nerve impulses. With its various cell types, it puts out peptides such as vasopressin and vasoactive intestinal peptide) and neurotransmitters.

The SCN controls when we get sleepy and when we wake up, when we are active and when we get hungry. The SCN gets information about light and dark from the retina in the eye so it can adjust itself to the true 24 hours. To do this it uses only about 20,000 cells.

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Suprachiasmatic nucleus Facts for Kids. Kiddle Encyclopedia.