Uploaded February 2021 | Updated September 2026, 1 week ago
Circadian rhythms (biological clocks) control many aspects of our lives. Our sleep, appetite or body temperature are controlled by circadian rhythms. But what happens if these biological clocks, circadian rhythms are not working anymore? And how can we control our circadian rhythms to sleep better?
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🔬Me being funny on other media:
Twitter: twitter.com/CSteinek
Discord: discord.gg/9VKnTSF
Adult human beings need roughly need between 7.5 and 8.5 h sleep per day. And yet, one third of the US population sleep less than 7 hours on weekday nights. Sleep is controlled by a special biological clock called the circadian rhythm. As the name suggest, these biological clocks are repeated every 24 hours. In other words, cells in our bodies have circadian rhythms. Our sleep is modulated by 20000 cells which constitute the suprachiasmatic nucleus. As we wake up in the morning, our body temperature rises and we feel sharp. During the day, the suprachiasmatic nucleus blocks melatonin which would otherwise make us feel tired. And shortly before we go to sleep in the evening, the melatonin is not blocked anymore and we become sleepy. This cycle will continue each day of our lives. Besides modulating sleep, the same cells also modulate our alertness, attention, perception, and working memory.
Our circadian rhythms are controlled by "zeitgeber". Zeitgeber are external influences which finetun our biological clocks. The sun is the most famous zeitgeber and it adjusts our circadian rhythms on a daily basis.
But what happens if the circadian clock does not work? Most of us might experience mild forms of sleep deprivation but some might suffer from extreme forms of circadian rhythm sleep disorders. Babies also do not have an intact circadian rhythm while people who suffer from bipolar disorder are also described to have disturbed circadian rhythms.
We can improve our sleep quality by taking some measures. We can try to avoid LED screens before we go to sleep in order to not disturb our biological clocks. We could also avoid caffeine or alcohol and exercise. On a larger scale, governments could delay school start or companies could introduce more flexible working hours.
For your reading:
Takaesu, Yoshikazu. "Circadian rhythm in bipolar disorder: a review of the literature." Psychiatry and clinical neurosciences 72.9 (2018): 673-682.
Zhu, Lirong, and Phyllis C. Zee. "Circadian rhythm sleep disorders." Neurologic clinics 30.4 (2012): 1167-1191.
Cohen, R. A., & Albers, E. H. (1991). Disruption of human circadian and cognitive regulation following a discrete hypothalamic lesion: A case study. Neurology, 41(5), 726–729. doi:10.1212/wnl.41.5.726
Farhud, D., & Aryan, Z. (2018). Circadian rhythm, lifestyle and health: a narrative review. Iranian journal of public health, 47(8), 1068.
Images:
Some pictures were derived from Servier Medical Art by Servier. You can find over 3000 free medical images here: smart.servier.com
A non-colored Emoji by emojione project, A non-colored Emoji from emojione project
Sleep cycles by Kernsters, CC BY-SA 3.0
Budding yeast by DBCLS, CC BY 3.0
Social Media by Ibrahim.ID, CC BY-SA 4.0
Rat brain cultures by GerryShaw, CC BY-SA 3.0
Light Therapy device by Alhmodeus, CC BY-SA 3.0
Some videos were derived from Videezy.com
Music:
Body:
Title: Buddha by Kontekst
Genre and Mood: Hip Hop & Rap + Bright
Artist: incompetech.com
Title: Danse Morialta by Kevin MacLeod (Creative Commons Attribution 4.0 )
Title: Bread (Prod. by Lukrembo) jazz type beat “marshmallow”
Title: Rudolph by Lukrembro
Title: Art of Silence by Uniq
Tape Recorder: freesound.org/people/magedu/sounds/273437
About Clemens Steinek:
CLEMENS STEINEK is a postgraduate student/youtuber (LifeLabLearner) who is currently conducting stem cell research in Germany.
Circadian rhythms (biological clocks) control many aspects of our lives. Our sleep, appetite or body temperature are controlled by circadian rhythms. But what happens if these biological clocks, circadian rhythms are not working anymore? And how can we control our circadian rhythms to sleep better?
🔬 Subscribe for more awesome biomedical research: bit.ly/2SRMqhC
🔬Me being funny on other media:
Twitter: twitter.com/CSteinek
Discord: discord.gg/9VKnTSF
Adult human beings need roughly need between 7.5 and 8.5 h sleep per day. And yet, one third of the US population sleep less than 7 hours on weekday nights. Sleep is controlled by a special biological clock called the circadian rhythm. As the name suggest, these biological clocks are repeated every 24 hours. In other words, cells in our bodies have circadian rhythms. Our sleep is modulated by 20000 cells which constitute the suprachiasmatic nucleus. As we wake up in the morning, our body temperature rises and we feel sharp. During the day, the suprachiasmatic nucleus blocks melatonin which would otherwise make us feel tired. And shortly before we go to sleep in the evening, the melatonin is not blocked anymore and we become sleepy. This cycle will continue each day of our lives. Besides modulating sleep, the same cells also modulate our alertness, attention, perception, and working memory.
Our circadian rhythms are controlled by "zeitgeber". Zeitgeber are external influences which finetun our biological clocks. The sun is the most famous zeitgeber and it adjusts our circadian rhythms on a daily basis.
But what happens if the circadian clock does not work? Most of us might experience mild forms of sleep deprivation but some might suffer from extreme forms of circadian rhythm sleep disorders. Babies also do not have an intact circadian rhythm while people who suffer from bipolar disorder are also described to have disturbed circadian rhythms.
We can improve our sleep quality by taking some measures. We can try to avoid LED screens before we go to sleep in order to not disturb our biological clocks. We could also avoid caffeine or alcohol and exercise. On a larger scale, governments could delay school start or companies could introduce more flexible working hours.
For your reading:
Takaesu, Yoshikazu. "Circadian rhythm in bipolar disorder: a review of the literature." Psychiatry and clinical neurosciences 72.9 (2018): 673-682.
Zhu, Lirong, and Phyllis C. Zee. "Circadian rhythm sleep disorders." Neurologic clinics 30.4 (2012): 1167-1191.
Cohen, R. A., & Albers, E. H. (1991). Disruption of human circadian and cognitive regulation following a discrete hypothalamic lesion: A case study. Neurology, 41(5), 726–729. doi:10.1212/wnl.41.5.726
Farhud, D., & Aryan, Z. (2018). Circadian rhythm, lifestyle and health: a narrative review. Iranian journal of public health, 47(8), 1068.
Images:
Some pictures were derived from Servier Medical Art by Servier. You can find over 3000 free medical images here: smart.servier.com
A non-colored Emoji by emojione project, A non-colored Emoji from emojione project
Sleep cycles by Kernsters, CC BY-SA 3.0
Budding yeast by DBCLS, CC BY 3.0
Social Media by Ibrahim.ID, CC BY-SA 4.0
Rat brain cultures by GerryShaw, CC BY-SA 3.0
Light Therapy device by Alhmodeus, CC BY-SA 3.0
Some videos were derived from Videezy.com
Music:
Body:
Title: Buddha by Kontekst
Genre and Mood: Hip Hop & Rap + Bright
Artist: incompetech.com
Title: Danse Morialta by Kevin MacLeod (Creative Commons Attribution 4.0 )
Title: Bread (Prod. by Lukrembo) jazz type beat “marshmallow”
Title: Rudolph by Lukrembro
Title: Art of Silence by Uniq
Tape Recorder: freesound.org/people/magedu/sounds/273437
About Clemens Steinek:
CLEMENS STEINEK is a postgraduate student/youtuber (LifeLabLearner) who is currently conducting stem cell research in Germany.
