i need some place to save this and e-mail sucks! p.s. i get paid 10$/hr to take notes hehe
PSYCHOLOGY 100:12 Wednesday, 17 October, 2005
Professor Carlin
Lecture 4 / Wednesday, 17/10/05
Page 1 of 2
Copyright 2005 by Professor Carlin
ANNOUNCEMENTS
There will be a quiz covering chapters 4 and 5 next Wednesday, October 26, 2005.
LECTURE
Biological Rhythms. We are starting Chapter 5 today that has to do with body rhythms and mental states. Our body and environment go through a lot of different cycles of different lengths. Today we are going to look at three different rhythms. The first is the Circadian Rhythm is a cycle that lasts twenty-four hours and has an even occurring once in it. Two examples of this is the sleep-wake cycle, that I’m sure most are familiar with, and body temperature. Generally a person is awake for a certain amount of time and asleep for a certain amount of time; one wake and one sleep within a twenty-four hour period. Body temperature is one that we are less aware of, but it does fluctuate in a regular cycle throughout the day.
Another cycle that our body and environment go through is called an Infradian Rhythm. This cycle has events that occur during a longer period of time, such as a month or year. A female’s menstruation cycle is an example of this, as well has migration and hibernation. Every year you see the birds fly and animals go to sleep; they do this once a year. The last rhythm we are going to talk about is the Ultradian Rhythm, which has events that occurs more than once in a twenty-four hour cycle. The stages of sleep would be an example of this, because when you are asleep you go through the different stages many times throughout the night. Hormonal levels and stomach contractions are two other examples of Ultradian Rhythm.
Next lets talk more about how and why biological rhythms occur. Biological rhythms are regular fluctuations in biological systems. Edogenous rhythms occur in the absence of external cues, such as sunlight. If you were in a room without windows to see the sun or even a television - because you can sometimes tell what time it is by what’s on TV - then your body will create its own edogenous rhythm. For some people it will be less than twenty-four hours - about twenty-three hours - but for most of us it will be more than twenty-four hours - around 25 hours. The biological rhythms are controlled by a master clock in the suprachiasmatic (SCN) nucleus in the hypothalamus. People talk about their biological clocks ticking away, referring to age, but its really just referring to our natural rhythms. The SCN regulates melatonin - it’s the one that reports back the external clues for rhythms to follow by.
What are some examples that cause our rhythms to run out of sync with the rest of environment or could cause us to change our rhythms to fit the environment? Jet lag could cause our rhythms to run out of sync and maybe force ourselves to change it. If you are flying from Cape Breton to Victoria, BC, at 10 o’clock PM and arrive there at 6 o’clock PM, your body is telling you to sleep when everyone else is eating dinner. Or when you are sick and your body just wants to sleep, that’s another example of your rhythm getting off schedule.
A question that scientists have been trying to figure out is: do infradian rhythms affect mood? When it comes to seasonal changes, studies have shown that people become more depressed, and they believe there’s a link with the amount of sunshine. This disorder is called Seasonal Affective Disorder (SAD). Studies have also proven that there is no correlation between a women’s menstruation cycle and mood fluctuation during that time.
Professor Carlin
Lecture 4 / Wednesday, 17/10/05
Page 1 of 2
Copyright 2005 by Professor Carlin
ANNOUNCEMENTS
There will be a quiz covering chapters 4 and 5 next Wednesday, October 26, 2005.
LECTURE
Biological Rhythms. We are starting Chapter 5 today that has to do with body rhythms and mental states. Our body and environment go through a lot of different cycles of different lengths. Today we are going to look at three different rhythms. The first is the Circadian Rhythm is a cycle that lasts twenty-four hours and has an even occurring once in it. Two examples of this is the sleep-wake cycle, that I’m sure most are familiar with, and body temperature. Generally a person is awake for a certain amount of time and asleep for a certain amount of time; one wake and one sleep within a twenty-four hour period. Body temperature is one that we are less aware of, but it does fluctuate in a regular cycle throughout the day.
Another cycle that our body and environment go through is called an Infradian Rhythm. This cycle has events that occur during a longer period of time, such as a month or year. A female’s menstruation cycle is an example of this, as well has migration and hibernation. Every year you see the birds fly and animals go to sleep; they do this once a year. The last rhythm we are going to talk about is the Ultradian Rhythm, which has events that occurs more than once in a twenty-four hour cycle. The stages of sleep would be an example of this, because when you are asleep you go through the different stages many times throughout the night. Hormonal levels and stomach contractions are two other examples of Ultradian Rhythm.
Next lets talk more about how and why biological rhythms occur. Biological rhythms are regular fluctuations in biological systems. Edogenous rhythms occur in the absence of external cues, such as sunlight. If you were in a room without windows to see the sun or even a television - because you can sometimes tell what time it is by what’s on TV - then your body will create its own edogenous rhythm. For some people it will be less than twenty-four hours - about twenty-three hours - but for most of us it will be more than twenty-four hours - around 25 hours. The biological rhythms are controlled by a master clock in the suprachiasmatic (SCN) nucleus in the hypothalamus. People talk about their biological clocks ticking away, referring to age, but its really just referring to our natural rhythms. The SCN regulates melatonin - it’s the one that reports back the external clues for rhythms to follow by.
What are some examples that cause our rhythms to run out of sync with the rest of environment or could cause us to change our rhythms to fit the environment? Jet lag could cause our rhythms to run out of sync and maybe force ourselves to change it. If you are flying from Cape Breton to Victoria, BC, at 10 o’clock PM and arrive there at 6 o’clock PM, your body is telling you to sleep when everyone else is eating dinner. Or when you are sick and your body just wants to sleep, that’s another example of your rhythm getting off schedule.
A question that scientists have been trying to figure out is: do infradian rhythms affect mood? When it comes to seasonal changes, studies have shown that people become more depressed, and they believe there’s a link with the amount of sunshine. This disorder is called Seasonal Affective Disorder (SAD). Studies have also proven that there is no correlation between a women’s menstruation cycle and mood fluctuation during that time.