Suprachiasmatic nucleus

Definition

The suprachiasmatic nucleus (SCN) is a tiny region of the brain located in the hypothalamus. It acts as the primary circadian pacemaker, regulating sleep-wake cycles and other daily rhythms.

5 Must Know Facts For Your Next Test

1. The SCN receives direct input from the eyes through the retinohypothalamic tract.
2. It helps synchronize the body's internal clock with external light-dark cycles.
3. SCN neurons exhibit intrinsic rhythmic activity even in isolation, demonstrating their role in circadian rhythms.
4. Disruptions to SCN function can lead to sleep disorders and other circadian rhythm-related issues.
5. Light exposure at night can alter SCN signaling, impacting sleep patterns and overall health.

Review Questions

• What is the primary function of the suprachiasmatic nucleus?
• How does the SCN receive information about external light conditions?
• What are some potential consequences of disrupted SCN function?

Related terms

Circadian Rhythms: Biological processes that display an endogenous oscillation of about 24 hours.

Hypothalamus: A region of the brain responsible for hormone production and regulation of essential bodily functions.

Retinohypothalamic Tract: A neural pathway that conveys light information from the retina to the suprachiasmatic nucleus.