Biological Rhythm Definition

Biological rhythm is a phrase often used interchangeably with circadian

rhythm. These rhythms are a series of bodily functions regulated by your
internal clock. They control cycles like sleep and wakefulness, body
temperature, hormone secretion, and more.
Your body maintains its biological rhythms through a variety of
chemicals at the molecular level in response to your environment. Your
light exposure, eating habits, and other environmental cues can
maintain or disrupt your biological rhythms. Disrupting your biological
rhythms can lead to serious health problems.
The Biological rhythms are the natural cyclic changes in the body. It
maintains both the chemical or function changes. It functions as an
internal clock master and coordinates with the other clock in the body.
They are made up of thousands of nerve cells, which sync to the body
functions. The biological clock in human located in the brain and
connected with the nervous system. The periodic biological fluctuation
in the body corresponds to the environmental changes and biological
changes.

How Biological Rhythms Work

Your biological rhythms are tied to an internal clock in your brain called
the suprachiasmatic nucleus (SCN). It is located in your hypothalamus.
This is the area of your brain that manages the autonomic nervous
system and the pituitary gland. Your SCN sends signals throughout the
day to regulate your body’s activity.
In cycles. Most biological rhythms work in roughly 24-hour cycles.
Others, such as menstrual cycles, work over longer timeframes. Each
type of biological rhythm has a certain name to show how long it lasts:

 Diurnal (night and day)

 Circadian (24 hours)
  Ultradian (less than 24 hours)
 Infradian/Circalunar (1 month)
 Circannual (1 year)
 Circadian and diurnal rhythms, which control functions like sleep,
body temperature, and hormonal changes, are most affected by
light. Sunlight tells your SCN what time it is and when to perform
certain functions. Other factors that influence your internal clock
are exercise, hormones, and any medications you might be taking.
 Studies have shown the power of the internal clock by placing
people in environments without the cues necessary for their
circadian rhythms. Even without light cues, your SCN can maintain
your body’s processes for a time with only slight deviations in its
normal 24-hour rhythms.
 Individual chronotypes. If your internal clock is so powerful, then
why is it so hard to wake up in the morning? This is due to a
circadian pattern called your chronotype. It is the biological
tendency to deviate from a 24-hour cycle.
 Night owls and early birds. Studies have also shown how the
body’s circadian rhythms continue even in total darkness. Even
without any light, people’s individual rhythms deviated only
slightly from a strict 24-hour cycle. The population’s circadian
cycles ranged on average between 23.5 hours and 24.6 hours.
 These deviations are due to people's personal chronotypes.
Researchers believe them to be the cause of people being either
an early bird or a night owl.

Types of Biological Rhythms

Based on the functions of Biological rhythms are classified into four
types. The types of biological rhythms are
1. Circadian rhythms

2. Diurnal rhythms
 3. Ultradian rhythms

4. Infradian rhythms

Circadian Rhythms: The Circadian rhythm is a 24-hour cycle, It is a

part of the body’s internal clock. They are running to carry our
essential functions and process of the body. One of the well-known
circadian rhythms is the sleep-wake cycle. The different system of the
body follows the master clock of the brain, which synchronize with
circadian rhythms. The circadian clock plays an important role in a
physical, mental, and behavioural role that depends on light and dark.

Diurnal Rhythms: The diurnal rhythms are also known as

endogenous rhythms. It syncs the day and night with circadian
rhythms. It is mainly influenced by environmental clues like climate
changes.

Ultradian Rhythms: The Ultradian rhythms occur more than once a

day. It lasts for short period at high frequency. For example, deep
sleep for ninety minutes. The alertness and hormone level follow the
ultradian rhythms.

Infradian Rhythms: A biological rhythm, which lasts for more than 24

hours is because of Infradian rhythms. For example, the menstrual
cycle in women occurs every 28 days.

Biological Clock in Humans

In the human body, Suprachiasmatic Nucleus (SCN) present in the
brain is the main biological clock, which regulates the circadian rhythm
of sleep. The Suprachiasmatic Nucleus is located up the right corner of
the nervous system in the hypothalamus. Here, the light stimulates the
retina’s receptors and sends a signal to the Suprachiasmatic Nucleus.
Then they send a signal to the pineal gland for melatonin secretion.
The melatonin hormone regulates the proper sleep cycle. Serum
cortisol concentrations rapidly increase in the early morning hours,
gradually decrease during the day, with small elevations after meals,
and remain decreased for much of the night.
What are the Types of Biological Rhythm Disorders?
Every biological disorder impacts the circadian rhythm. The biological
rhythms are disturbed by various factors.

Sleep Disorders: The body’s health is related to the sleep cycle. The
prolonged distribution of the regular sleep cycle affects the biological
rhythms. It causes sleeping disorders like insomnia.

Jet Lag: Overnight travel across the time zones disturbs the circadian
rhythm. And causes biological rhythm disorders.

Mood Disorders: The biological rhythm disorders also occur if people

lack exposure to sunlight. This causes depression, seasonal affective
disorders, and bipolar disorders.

Shift Work Disorders: The people who are working in the rotational
shifts cause changes in circadian rhythms and it may lead to shift work
disorders.

Biological Rhythm Disorder Causes

Biological rhythms psychology disorders affect the person’s health and
hormonal changes. The list of factors that causes the biological rhythm
disorder are
1. Anxiety

2. Depression

3. Lack of mental alertness

4. Diabetes

5. Obesity

6. Daytime sleepiness
 7. Physically inactive

8. Irregular sleeping habits

9. Being more accident-prone

Risks of Biological Rhythm Disorder

The people who are working in the rotations shifts are facing high risks
of biological rhythm disorder. This causes hormonal imbalance and
various other diseases. The US researchers found that about 15% of
the rotational shift workers are getting affected by these disorders.

For example, healthcare workers, travellers, police officers, drivers,

pilots, and others in transportation, food preparers, and servers, and
firefighters are at a high risk of biological rhythm disorders. According
to the NSF survey, only 63% of workers felt that they had enough
sleep.

How to Maintain a Healthy Circadian Rhythm?

It is important to have a balanced circadian rhythm for maintaining a
healthy life cycle. Here, the perfect chart for balancing healthy
circadian rhythms is listed.
1. Exploring natural light and setting the body clock cycle
accordingly helps to build a healthy circadian rhythm.
2. To have a perfect sleep time, practice the biological clock sleep
by maintaining regular bedtime as it affects the biological clock
circadian rhythm
3. A regular exercise with healthy activity during the daytime
supports the biological rhythms psychology and helps to sleep
earlier.
4. Alcohol consumption and caffeine affect sleep and biological
rhythms. Reducing intake of caffeine impacts the hormone.
5. Often exploring the artificial lights during night time impacts the
body clock cycle. Limited exploring to electronic gadgets helps to
improve healthy biological clock in humans
 6. Day time sleep affects the natural routine and impacts the
biological clock circadian rhythm.

What Do Biological Rhythms Affect?

The main biological rhythm most people are concerned with is the diurnal sleep-wake cycle. It is
the most obvious cycle you deal with on a regular basis. It has a powerful impact on your health.
During the day as you experience light cues, your SNC sends signals of alertness to tell your
body it’s time to be awake. As the sun sets, your SNC signals for the production of melatonin, a
sleep hormone. Afterward, it continues signaling to your body to stay asleep.
Other than sleep, your biological rhythms influence important functions such as:

 Metabolism
 Heart rate
 Blood pressure
 Body temperature
 Hormone levels
 Urine production

Your biological rhythms are also tied to the regulation of blood sugar and cholesterol, risks
associated with mental health that lead to depression, bipolar disorder, and neurodegenerative
diseases. Biological rhythms also influence your immune system, DNA repair processes, and
cancer treatment effectiveness.

Possible Complications
Your biological rhythms can be disrupted by short-term and long-term causes. Sometimes these
disruptions are caused by natural changes to your biological rhythms as you age. Other times, it
can be due to alterations in your environment and activities.

et lag disorder. Jet lag is the most common disruption of your

biological rhythms. This occurs when someone travels across several
time zones, such as flying between two distant countries. The rapid
change between time zones confuses your internal clock. The length of
time jet lag's symptoms last will vary depending on the number of time
zones crossed. Some of them are:

 Insomnia
 General sleepiness or fatigue
 Indigestion
 Irritability
  Lack of focus

Shift work disorder. Work is another major disruption. Jobs that

require working in shifts (as opposed to a 9 a.m. to 5 p.m. job) often limit
your exposure to typical daylight cycles. Nighttime shifts are major
culprits for this type of disruption. They typically force you to sleep
during the daytime, conflicting with your natural inclinations.
Delayed sleep phase disorder (DSP). This type of disruption is usually
a problem for night owls. People who have DSP tend to get tired far later
than the average person and sleep in later than normal. DSP is mostly
seen in teens and young adults and can make waking up for school or
work more difficult.
Irregular sleep-wake rhythm disorder. This is a rare disorder that
makes it so a person doesn’t have a consistent sleep pattern. It could be
characterized by constantly changing bedtimes or regularly napping
throughout the day. Irregular sleep-wake rhythm disorder is commonly
associated with brain conditions such as dementia or brain injuries.

Staying in Time
To keep your biological rhythms in time and consistent, practice the
following habits:

 Soak in some sunlight early in your day to reinforce your biological

cues.
 Go to bed and wake up at the same time every day.
 Exercise during the day to make it easier to sleep at night and to
reinforce your waking hours.
 Avoid caffeine after 12 p.m. to make sure you can fall asleep.
 Avoid artificial light from electronic devices before bed.
 Don’t take long naps and don’t nap too close to bedtime.