1. SLEEP, AROUSAL AND BIOLOGICAL RHYTHMS. 25/01/2016
hubert kairuki memorial university faculty of medicine and nursing department of behavioral science and medical ethics
SLEEP, AROUSAL AND BIOLOGICAL RHYTHMS.
25/01/2016

2. FACILITATOR;
DR. ISAAC LEMA
PRESENTERS;
Sara Ahmed
Dhariha Amour
Samira Othman
Seif Salum
Maryam Khamis
Arthur Zayumba
Mohamed Omar
Firdaus Nassor
Mike Venant
Salma Khalfan

3. Table of contents; INTRODUCION OBJECTIVES DEFINITION OF TERMS
MAIN DISCUSSION
SUMMARY
CONCLUSION
RECOMMENDATION
REFFERENCES

4. ….

5. INTRODUCTION
Behaviour can be studied both from a qualitative and from quantitative point of view.
In behaviour, there are behavioural change strategies. The change strategies to be discussed today are ;
Sleep
Arousal
Biological rhythms

6. objectives At the end of this presentation you should be able to ;
Understand the concept of sleep, arousal and biological rhythms.
Describe the Yerkes Dodson Law and curve
Effects of drugs on arousal
Stages of sleep and characteristics
Discuss problems associated with REM and slow- wave sleep
Understand the types of biological rhythms; Circadian, Ultradian and Infradian rhythms.

7. Definition of terms;
Sleep- is a naturally recurring state of mind characterized by altered consciousness, relatively inhibited sensory activity, inhibition of nearly all voluntary muscles and reduced interactions with surroundings.
Arousal- is the physiological and psychological state of being awake.
Biological rhythms- are our daily rhythms or cycles to many of our physiological functions or activities.

8. Arousal….
Generally arousal is defined by sleep at one end and extending through drowsiness and alertness to excitement and panic and the other. This variation on neural physiological bases lie within Ascending Reticular Activating System(ARAS) whose integrity is necessary for efficient working activity and which serves to mediate between external event and internal activation Monotonous unchanging stimuli decrease arousal and move the organism nearer sleep.

9. Effects of drugs on arousal…
Drugs that can act on Central Nervous System can be classified in terms of the effects on arousal thus Stimulants such as caffeine increase arousal WHILE Depressants like alcohol lowers it.

10. Yerkes-dodson curve
Based on variety of tasks there is a relationship between the level of arousal and efficiency of performance.This relationship is explained by the Yerkes-Dodson curve.

11. Yerkes-Dodson Curve in detail

12. Sleep;
Sleep is a condition that is not static, and is characterized by a continual shifting between different states. These states can be better understood by considering the stages of sleep. These stages of sleep can be interpreted by using an Electroencephalogram (EEG).
The EEG is a test that detects electrical activity in the brain using electrodes attached to the scalp. Brain cells are active all the time, even during sleep, hence wavy lines will be recorded during sleep on an EEG.

13. Sleep…
The Electroencephalogram (EEG)

14. EEG..

15. EEG Readings.

16. Sleeping hours required by age;
SLEEP RANGE
Newborns (0-3 months)
14-17 hours
Infants (4-11 months)
12-15 hours
Toddlers (1-2 years)
11-14 hours
Preschoolers (3-5 years)
10-13 hours
School age children (6-13 years)
9-11 hours
Teenagers (14-17 years)
8-10 hours
Younger adults (18-25 years)
7-9 hours
Adults (26-64 years)
Older adults (65+)
7-8 hours

17. Stages Of Sleep.. STAGE ONE :
Stage one sleep is defined by low amplitude and Frequency of the EEG. Primarily within Frequency of 6-10 Hz. Stage one is characterized by :
An Interim between conciousness and sleep.
During this stage, your eyes are closed, but it’s easy to wake you up. It may last for 5 to 10 minutes.

18. Stages Of Sleep… STAGE TWO
Is among the intermediate stages of sleep. Characterized by:
Slow heart rate
Brain does less complicated tasks
EEG consists of low voltages, fast frequencies.
The body is preparing for a deep sleep.
STAGE THREE
This is the deep sleep stage, it’s harder to rouse one during this stage. If a person is woken up during this stage, one may feel disoriented for some time. During the deep stage, the body repairs and regrows tissues.

19. Stages Of Sleep.. STAGE FOUR:
A person in stage four is more difficult to rouse compared to stage one. More time is spent in stage four in the first half of sleep then in the second half.
Throughout the period of sleep, the depth of sleep changes in a cyclical manner

20. Sleep cycle;

21. The Stages Of Sleep.
Sleepers usually pass through Four stages of sleep. An addition being the REM sleep (Rapid eye movement). These stages pass cyclically, it is essential to understand each stage.

22. REM
REM (Rapid Eye Movement) stage or the Paradoxical sleep is the deepest sleep, in that the sleep is more difficult to arouse compared to the other stages. REM periods last for about fifteen to twenty minutes and takes up 20% of a young adult’s sleep.
Neonates spend about 50% of their sleep time in REM, whereas in over 60 year olds, the proportion is reduced to 15%.
REM sleep is known as the dreaming sleep.
According to some sources, is the fifth stage of sleep.

23. Problems associated with REM
RBD ( REM sleep behaviour disorder)
The exact cause of RBD is still unknown, though the disorder may occur in association with genetic diseases like Parkinson’s disease.
Insomnia :
A condition when one cant sleep. May happen due to jet lag in some cases.
Sleep walking:
is a disorder that causes people to get up and walk while they are asleep,mostly happens in childhood but adults can do it too.

24. BIOLOGICAL RHYTHMS
The sleep waking cycle is among the most common biological cycles identified in most species. Other obvious biological rhythms are the menstrual cycle.
Rhythmicity is considered as a fundamental property of biological systems, at all levels of complexity from the cell to the whole organism.
At behavioural level, moods or mood swings are identified as a biological rhythm characterized by an ‘up-down’ dimension.
Many of the biological rhythms run on a 24 hour cycle. Such rhythms are known as Circadian rhythms

25. Biological rhythm..

26. The Circadian Rhythm
Circa comes from a latin word meaning ‘around’ while dia comes from a word meaning ‘day’. The cycle would exist even if the person is unaware of the time. Examples of this rhythm are:
Sleep
Temperature
Although neuroscientists are still not sure of how the brain keeps track of time to initiate this cycle. There are several areas of the brain that may be involved including the ‘Superchiasmatic nucleas’ found in the hypothalamus.

27. Cont..

28. Other Rhythms.. ULTRADIAN RHYTHMS
Are rhythms that have a shorter period than 24 hours. Examples of such rhythms are like eye blinks (per minute),respiration, heart beat and even sleep patterns.
Note that although sleep is a circadian cycle. There are patterns within sleep as well. Sleep is not just a Long snooze but a set of several sleep cycles which may last each for approx 90 minutes.
INFRADIAN RHYTHMS
Are rhythms that last longer than 24 hours. They may be more than 24 hours with a few excess hours or may last for days. A good example is the Menstrual Cycle.

29. Menstrual Cycle

30. Conclusion
Thus the knowledge on sleep, its patterns and biological rhythms associated, help us describe the mood of a person, general health and other mental aspects.
It is important to study these patterns since they are a major part of Behaviour Change Strategies.

31. Thank you!!

33. References
Lecture notes on Behavioural Science by A.C.P Sims & W.I. Hume
Study.com/academy/lesson/biological-rhythm- definition-lesson-quiz.html
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