How Sleep and Body Clock Disruptions in Severe Illness Are Linked to Natural Immune Defenses

The master molecular clock, located in the suprachiasmatic nucleus, controls circadian rhythms that influence immune responses.

• Circadian rhythms are primarily regulated by light detected by the retina.
• Retinal ganglion cells send signals to the suprachiasmatic nucleus, which acts as the master clock.
• The master clock indirectly affects the innate immune system through various biological systems.
• Peripheral clocks in innate immune cells are regulated by circadian rhythm proteins.
• Alterations in circadian rhythms in critically ill patients may lead to impaired immune responses.

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