Outline and Evaluate one or more biological rhythms
“Outline and evaluate research into one or more biological rhythms” [research = theories and studies]
There are three main biological rhythms, which are called infradian, circadian and ultradian. Ultradian rhythms occur multiple times in one day. Circadian rhythms are cycles, which occur once a day, so within the 24 hours such as the sleep-wake cycle. Infradian rhythms are less frequent once in a day such as the menstrual cycle or hibernation. The research into these rhythms offers an insight into how the body is influenced by exogenous zeitgebers and endogenous pacemakers, but it is still nonetheless unclear what it more influential.
An example of circadian rhythms is the sleep-wake cycle that evidence suggests that exogenous pacemakers control it. For example, the theory is that the suprachiasmatic nucleus has an involvement in controlling the sleep-wake cycle. Ralph et al investigated how the suprachiasmatic nucleus (SCN) may be involved in the sleep-wake cycle. By examining hamsters that had a 20-hour sleep-wake cycle, he was able to extract the SCN and enter it into other hamsters with a 24-hour cycle. Ralph found that the group of hamsters with the 24-hour sleep-wake cycle eventually had a 20-hour sleep-wake cycle. Ralph’s study would suggest that endogenous pacemakers rather than other external influences control the sleep-wake cycle. However, Ralph’s experiment is very limited by the inability to be able to generalise this study to humans as this experiment is only done on animals. Yet Siffre came to similar conclusions as he took part in his longitudinal study. He found after taking himself out of humanity and into a cave for six months with only artificial light, taking away external cues, he found that his own body clock changed to 25 hours rather than a 24-hour sleep wake cycle. Therefore, with the external cues removed, this would suggest that endogenous pacemakers take an influential role in there. Likewise, there is a problem with
There are three main biological rhythms, which are called infradian, circadian and ultradian. Ultradian rhythms occur multiple times in one day. Circadian rhythms are cycles, which occur once a day, so within the 24 hours such as the sleep-wake cycle. Infradian rhythms are less frequent once in a day such as the menstrual cycle or hibernation. The research into these rhythms offers an insight into how the body is influenced by exogenous zeitgebers and endogenous pacemakers, but it is still nonetheless unclear what it more influential.
An example of circadian rhythms is the sleep-wake cycle that evidence suggests that exogenous pacemakers control it. For example, the theory is that the suprachiasmatic nucleus has an involvement in controlling the sleep-wake cycle. Ralph et al investigated how the suprachiasmatic nucleus (SCN) may be involved in the sleep-wake cycle. By examining hamsters that had a 20-hour sleep-wake cycle, he was able to extract the SCN and enter it into other hamsters with a 24-hour cycle. Ralph found that the group of hamsters with the 24-hour sleep-wake cycle eventually had a 20-hour sleep-wake cycle. Ralph’s study would suggest that endogenous pacemakers rather than other external influences control the sleep-wake cycle. However, Ralph’s experiment is very limited by the inability to be able to generalise this study to humans as this experiment is only done on animals. Yet Siffre came to similar conclusions as he took part in his longitudinal study. He found after taking himself out of humanity and into a cave for six months with only artificial light, taking away external cues, he found that his own body clock changed to 25 hours rather than a 24-hour sleep wake cycle. Therefore, with the external cues removed, this would suggest that endogenous pacemakers take an influential role in there. Likewise, there is a problem with