Biological Rhythms

Question 1

Circadian Rhythm

Answer 1

Lasts about a day, a 24 hour cycle such as the sleep/wake cycle and core body temperature

Question 2

Ultradian Rhythm

Answer 2

A type of biological rhythm with a frequency of more than one cycle in 24 hours, such as stages of sleep

Largely under endogenous control

Question 3

Infradian Rhythm

Answer 3

Meaning more than 1 day but less than one year
E.g- women’s menstrual cycle

Question 4

What are all bodily rhythms are controlled by?

Answer 4

-Endogenous pacemakers- Internal biological structures that control and regulate the rhythm
-Exogenous pacemakers- external environmental factors that influence the rhythm

Question 5

Sleep Stages

Answer 5

First 4= Non-rapid eye movements
Fifth is rapid eye movement
One sleep cycle goes though all 5 stages

Question 6

Sleep Stage One

Answer 6

Light sleep
Eye and muscle activity slows, brain activity decreases, heart rate slows, temperature drops
Beta Waves= Alpha and Theta waves

Question 7

Sleep Stage Two

Answer 7

Light Sleep
Eye movement stops, muscle activity stops and brain waves slow
Beta Waves= Alpha and Theta waves accompanied with Sleep spindles and increased k complexes

Question 8

Sleep Stage Three

Answer 8

Deep Sleep
No eye or muscle movement, difficult to wake the sleeper. Physiological repair work is undertaken
Beta Waves= Very slow Delta waves

Question 9

Sleep Stage Four

Answer 9

Deep Sleep
Sleeper may be disorientated if woken
Beta Waves= Delta waves

Question 10

Sleep Stage Five

Answer 10

REM SLEEP
Heart and breathing rates levels increase. Eye movement is quick and irregular, blood pressure rises, muscles of the torso and limbs become paralysed. Sleeper begins to dream
Beta Waves= Desynchronised EEG activity resembling the awake brain

Question 11

SAD

Answer 11

Seasonal Affective Disorder
A depressive disorder
Symptoms are triggered in the winter months when the number of daylight hours becomes shorter
The hormone melatonin is implicated in the cause of SAD
During the night, melatonin is secreted and stops when it becomes light
During the winter, there is more darkness and so more melatonin
This is thought to have a knock on effect on the production of serotonin

Question 12

A03- Shift Work (Circadian Rhythm)

Answer 12

Practical application due to disruption to the sleep/wake cycle.
-Night shift workers experience a period of reduced concentration.
-Relationship between shift work and poor health.
May have economic implications in terms of how best to manage worker productivity.