Circadian Rhythm

Good Essays
Circadian rhythm

Although most people tend to think that manifestations of body function such as temperature and blood pressure are constant throughout the day, the fact is that many functions change in cyclic patterns – especially those that are affected by hormones, such as cortisol. These daily fluctuations, or circadian rhythms are fundamental to all organisms, from bacteria to humans. Circadian rhythms help coordinate and synchronize our internal body functions, as well as our interactions with the external world. The word circadian means around or approximately a day. The circadian rhythms are internal mechanisms that operate on an approximately 24 hour cycle. It’s most important function is to regulate the sleep/wake cycle. It also regulate the frequency of eating and drinking, body temperature, secretion of hormones, volume of urination, and sensitivity to drugs.

A few interesting ‘times’ during the 24 hour cycle is: the bowel movements, fastest reaction time, best coordination, and then the most interesting the highest testosterone secretion? This is all controlled by a group of cells called the suprachiasmatic nucleus.

The suprachiasmatic nucleus or SCN is a part of the hypothalamus and the main control center of the circadian rhythms of sleep and temperature. It is located above the opt chiasm. Any damage to the SCN results in less consistent body rhythms that are no longer synchronized to environmental patterns of light and dark. It results in the complete absence of a regular sleep-wake rhythm.

The optic chiasm is the part of the brain where the optic nerves partially cross. The optic chiasm is located at the bottom of the brain immediately the hypothalamus. The SCN is a pair of distinct groups of cells located in the hypothalamus. The SCN receives information about illumination through the eyes. The retina of the eye contains photoreceptors, which are used for conventional vision.

But the retina also contains

You May Also Find These Documents Helpful

  • Good Essays

    Circadian Rhythms

    • 3608 Words
    • 15 Pages

    1. Describe how circadian rhythms are associated with sleep deprivation. 2. Explain the results of the sleep deprivation assessment. 3. Do you agree, or disagree, with the results. Why, or why not? 4. If you are sleep deprived, what steps could you take to get more or better quality of sleep? Alternatively, if you are not sleep deprived, what techniques allow you to get quality sleep most nights of the week? Circadian rhythms: Their role and dysfunction in affective disorder Press…

    • 3608 Words
    • 15 Pages
    Good Essays
  • Good Essays

    Circadian Rhythms

    • 762 Words
    • 4 Pages

    Circadian rhythm sleep disorders are very disruptive to a person's health, and are a common occurrence in humans. By definition, circadian rhythm is the cyclical 24 hour period of human biological activity where people usually sleep for eight hours and are awake for sixteen. There are two main types of circadian rhythm disorders: exogenous and endogenous. Examples of exogenous disorders include shift worker disorder and jet lag disorder. Some endogenous disorders include advanced sleep phase…

    • 762 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    processes. Circadian rhythm in all mammals is a process that describes our inner master “clock” and our daily functionality. “Circadian timing is structured in such a way as to receive information from the external and internal environments, and its function is the timing organization of the physiological and behavioral processes in a circadian pattern (1)”. With the 24 hour cycle put in use we determine the sleeping and feeding patterns of all animals. Since the circadian rhythm is such a vital…

    • 1155 Words
    • 5 Pages
    Powerful Essays
  • Better Essays

    Describe circadian rhythms (8marks) Circadian rhythms occur every 24 hours; an example of a circadian rhythm is the sleep-waking cycle. We are diurnal animals who are active during the daytime and asleep at night, other animals are nocturnal they are active at night but asleep during the day. The circadian rhythm depends on the interaction of physiological and psychological processes to be tuned into the sleep-waking cycle so energy is provided when needed. As diurnal humans we have a fairly stable…

    • 1438 Words
    • 6 Pages
    Better Essays
  • Good Essays

    Circadian Interference Establishment of a ‘normal’ circadian rhythm in sleep/wake cycle and core body temperature and the effects of a sleep deprivation event on that rhythm. Introduction: Circadian rhythms are well documented and researched all over the natural world. Humans are subject to a circadian rhythm as well; being naturally diurnal animals, humans sleep during the night and are active during the day. It is also known that circadian rhythms affect more than just sleep wake cycles, but…

    • 1723 Words
    • 7 Pages
    Good Essays
  • Good Essays

    The Circadian rhythm is a daily cycle of biological activity based on a 24-hour period and influenced by regular variations in the environment, such as the alternation of night and day. Circadian rhythms include sleeping and waking in animals and flowers closing and opening. The 24-hour sleep–waking cycle is a good example of a circadian rhythm because it clearly illustrates that circadian rhythms depend on an interaction of physiological and psychological processes. Our fairly consistent sleep pattern…

    • 402 Words
    • 2 Pages
    Good Essays
  • Better Essays

    Adolescents’ Circadian Rhythms Sleep is the fuel that humans need to properly function. The amount of sleep people need is determined by their circadian rhythm, or biological clock. A teenager’s circadian rhythm differs from that found in an adult or younger child. While going through puberty, teenagers need more sleep than when they become adults. Researchers from the National Sleep Foundation have identified several changes in sleep patterns, sleep/wake systems, and circadian timing associated…

    • 1858 Words
    • 8 Pages
    Better Essays
  • Good Essays

    Tee Hng Class: MB1102 Module: Molecular Genetics Date: 6th January 2013 Circadian Rhythms From this experiment, using transgenic fly that can glow in the dark, a study of circadian rhythms was performed. Circadian Rhythm is like an internal body clock(biological clock) of an animal. And results obtained from experiment conducted with transgenic glowing fly, allowed one to come up with a few hypotheses, firstly, circadian rhythm repeats every 24 hours. When the glowing flies were placed in a dark environment…

    • 610 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Discuss the role of endogenous pacemakers in the control of circadian rhythms [AO1 8 marks, AO2 16 marks] An endogenous pacemaker is an internal biological clock that controls the way in which many of our biological rhythms behave. Many of these rhythms run on a 24 hour basis, such as the sleep/wake cycle, bodily temperatures and some of our hormones. The main endogenous pacemaker in mammals is the suprachiasmatic nucleus (SCN), which is located in the hypothalamus. It receives information…

    • 753 Words
    • 4 Pages
    Good Essays
  • Good Essays

    zeitgebers in the circadian rhythm. 24 Markers Circadian rhythm is rhythms that last 24 hours, one day. An example of a Circadian Rhythm is the sleep-wake cycle. Because this rhythm occurs daily, it is tempting to automatically assume that the factors which control it are exogenous zeitgebers, such as natural light patterns, TV, radio, birdsong, Research however has gone into this to find out what exactly controls the circadian rhythms. Research by Siffer implies that circadian rhythms are controlled…

    • 1205 Words
    • 5 Pages
    Good Essays