Context:
Recent article in The Hindu – Ultradian rhythms: the cycles of life
Ultradian Rhythm:
- Physiological patterns that all living things — from single-celled creatures to humans — adopt to function properly
- Biological rhythms that recur more frequently than once every 24 hours
- Shorter than circadian rhythms and lasts for 90 minutes
- Involves 2 types of sleep – Within 90 min sleep –
- Rapid Eye Movement (REM)sleep – The individual dreams
- Non – Rapid Eye Movement (non-REM) sleep – The individual to restore themselves physically and consolidate their memories
- Influence patterns of hormone release such as the pulsatile secretion of growth hormone, cortisol, and insulin.
- These hormonal fluctuations are essential for individuals to regulate metabolism, energy levels, and stress responses through the day.
- It governs various physiological processes, including heartbeat, breathing, hormonal release, and brain-wave activity.
Circadian Rhythm:
- The physical, mental, and behavioral changes an organism experiences over a 24-hour cycle
- Light and dark have the biggest influence on circadian rhythms
- In humans, nearly every tissue and organ has its own circadian rhythm, and collectively they are tuned to the daily cycle of day and night.
- Circadian rhythms influences – Sleep patterns, hormone release, appetite and digestion, temperature etc.
- The study of circadian rhythms is known as chronobiology.
Diurnal Rhythm:
- Circadian rhythm synced with day and night
- It can be either light-driven or clock-driven
- Rhythms are usually synchronized to environmental cues, such as the light-dark cycle.
Infradian Rhythm:
- Biological rhythms those last more than 24 hours
- Regulated by a complex interplay of biological mechanisms, including hormonal fluctuations, environmental cues, and genetic factors.
- Rhythms are controlled by internal biological clocks.
- Often seen in – Menstrual cycle in females, hibernation in animals, or seasonal breeding patterns in birds
Source: The Hindu
Previous Year Question
Consider the following1. Bats2. Bears3. RodentsThe phenomenon of hibernation can be observed in which of the above kinds of animals? [UPSC Civil Services Exam – 2014 Prelims]
(a) 1 and 2 only
(b) 2 only
(c) 1, 2 and 3
(d) Hibernation cannot be observed in any of the above
Answer: (c)
