Biological Rythms

Question 0

Infradian rhythms

Answer 0

Occur over a period greater than a day- e.g menstrual cycle

-yearly cycles classed as Infradian and also more specifically -‘circannual rhythms’ e.g- bird migration

Question 1

Circadian rhythms

Answer 1

Daily- 24 hour rhythms e.g. sleep-wake cycle

Question 2

Ultradian rhythms

Answer 2

Occur over a period of less than a day- e.g. Sleep cycles of deep sleep and light sleep

Question 3

Endogenous pacemaker

Answer 3

An internal clock- e.g. A biological clock

Question 4

Exogenous zeitgebers

Answer 4

An external ‘time giver’ or cue to time- e.g.tv programme, temperature, radio

Question 5

What is the role of the pineal gland?

Answer 5

Receptors respond to external light.
Manufactures and releases melatonin.
Acts on brainstem sleep mechanisms.

Question 6

What’s the role of the suprachiasmatic nucleus? (SCN)

Answer 6

Neurons have an in-built circadian firing pattern.
Regulates the manufacturing of melatonin in the pineal gland
Pineal gland and SCN jointly act as PACEMAKERS.

Question 7

Jet lag

Answer 7

More severe travelling from west to east.

Melatonin used to help.

Question 8

Shift work - 17% of working adults are shift workers

Answer 8

Backward movement has the same affect as travelling from west to east .
Increasing shift rotation to 21 days may give more time for adjustment.

Question 9

Example of a circadian rhythm

Answer 9

Sleep wake cycle

Question 10

Example of an Infradian rhythm

Answer 10

Menstrual cycle- governed by hormones

Question 11

What does an electroencephalograph do?

Answer 11

It measures the different types of brain activity (EEG)

Question 12

What are the two types of sleep?

Answer 12

Rem- Rapid Eye Movement

Non Rem
Stage 1-light sleep
Stage 2-light sleep
Stage 3-deep/ slow wave sleep
Stage 4-deep/ slow wave sleep

Question 13

In what order do we pass through the stages of sleep?

Answer 13

1-2-3-4-3-2-REM =90 minutes

Question 14

What happens when the SCN is lesioned or destroyed in a squirrel monkey? (Similar sleep patterns to humans)

Answer 14

Sleep cycles were severely disrupted as well as their circadian rhythms.

Question 15

Advantages of a rapidly rotating shift systems….

Answer 15

Can usually get a 24 hour period without work when they shift to another shift

Question 16

What is a rapidly rotating shift pattern?

Answer 16

Two or three successive periods on one shift…. earlies 6am…lates 2pm ….nights 10pm

Question 17

Which direction is shift working easiest in?

Answer 17

Forward / clockwise direction
Earlies-lates
Day is extended

Question 18

Which direction is shift working hardest in?

Answer 18

Backward rotating system- shortens day

Question 19

What is a circadian trough?

Answer 19

A period of time between 2am and 6am in which shift workers may feel very fatigued

Question 20

What negative effects may shift work have?

Answer 20

Poor quality sleep
Sleep deprivation
May struggle to sleep in the day so build up a ‘sleep debt’

Question 21

What illness has long term shift work been associated with?

Answer 21

Coronary heart disease and cancer

Longitudinal study of men- 15 years
Three fold incidence of CHD compared to the normal population
Cannot generalise results

Studies have not always been controlled

Question 22

How can the effects of shift work been lessened? (Horne 2006)

Answer 22

Increasing alertness- enabling them to work in bright light
Taking coffee- free coffee
Allowing short naps

Question 23

What is phase delay?

Answer 23

Individual goes to bed later and gets up later. Easier than going to bed earlier and getting up earlier (phase advance).

Question 24

What is phase advance?

Answer 24

Going to bed earlier and getting up earlier, harder than phase delay.

Question 25

People on rotating shift patterns dislike ......

Answer 25

Aspect of their work that disregards normal bodily rhythms and sleep-wake cycle.

Question 26

Work Schedules that take into account circadian principle are....

Answer 26

Better. They can do this by shifting shift patterns to a phase delay pattern.

Question 27

Managers of factories that use shift workers should consider....

Answer 27

Installing a free coffee machine Implementing a clockwise rotating shift system Providing a place for workers to rest Providing an appropriate level of lighting Providing a health service- ability to cope

Question 28

Jet lag and your internal biological clock...

Answer 28

When on a long haul flight your internal biological clock is different to the outside world, there is a dislocation of bodily rhythms

Question 29

What are the symptoms of jet lag?

Answer 29

``` Daytime sleepiness Fatigue Impaired alertness Trouble initiating and maintaining sleep Different people react differently ```

Question 30

Jet lag and Horne (2006) Larks- Owls-

Answer 30

People who typically go to bed early and wake up early (Larks)- cope with jet lag worse than (Owls)- people who go to bed late and wake up later.

Question 31

How many hours does a person need to adjust to a new time zone?

Answer 31

One day for each hour of time zone crossed with westbound travel A day and a half for each hour of time zone crossed in an eastbound direction.

Question 32

How can the effects of jet lag be lessened by taking a melatonin tablet?

Answer 32

Melatonin is naturally in the body and is released when it's dark. Taking a melatonin tablet can help make the person sleepy. Although if it's not dark, melatonin will not work as effectively with the biological clock. Spitzer 1999- doesn't always work- large scale study

Question 33

How can the effects of jet lag be lessened using a sleeping tablet?

Answer 33

Taking a sleeping pill when waking too early in the USA after a uk-USA flight. Horne 2006-ineffective-worsen or cause grogginess.

Question 34

How can the effects of jet lag be lessened by drinking coffee?

Answer 34

Coffee/ caffeine can be used as a method for relieving tiredness in the short term. Horne-2006 Study measure effect after 7 hour eastbound flight, caffeine was particularly effective at reducing daytime sleepiness.

Question 35

How can the effects of jet lag be lessened by increasing light levels?

Answer 35

Bright light can help reset the human body clock, going out in bright light will help the body readjust- suppresses melatonin.

Question 36

Neurons in the pineal gland.....

Answer 36

Convert the neurotransmitter serotonin Into the hormone melatonin.

Question 37

Melatonin acts on the brainstorm sleep mechanisms to help....

Answer 37

Synchronise the phases of sleep and waking, injections of melatonin can induce sleep in sparrows (Abraham 2000)

Question 38

The manufacture and release of melatonin is regulated by the amount of....

Answer 38

Light falling on the pineal gland, decreasing as light increases.

Question 39

The main biological clock is the....

Answer 39

Is the suprachiasmatic nucleus (SCN) which is found in the hypothalamus.

Question 40

Neurons in the SCN have....

Answer 40

an in built circadian firing pattern.

Question 41

The SCN regulates the manufacture and secretion of melatonin in the....

Answer 41

Pineal gland via an interconnecting pathway.

Question 42

A pathway from each eye connects the retina to the....

Answer 42

SCN, which indirectly influences the release of melatonin by the pineal gland.

Question 43

The pineal gland and the SCN both work together as....

Answer 43

Endogenous pacemakers.

Question 44

What is an example of an ultradian cycle?

Answer 44

The stages of sleep, light, deep and REM= 90 mins

Question 45

The main biological clock is the....

Answer 45

Is the suprachiasmatic nucleus (SCN) which is found in the hypothalamus.

Question 46

Neurons in the SCN have....

Answer 46

an in built circadian firing pattern.

Question 47

The SCN regulates the manufacture and secretion of melatonin in the....

Answer 47

Pineal gland via an interconnecting pathway.

Question 48

A pathway from each eye connects the retina to the....

Answer 48

SCN, which indirectly influences the release of melatonin by the pineal gland.

Question 49

The pineal gland and the SCN both work together as....

Answer 49

Endogenous pacemakers.