Bio Rhythms - Circadian Rhythm

Question 1

all livng organisms are subject to

Answer 1

biological rhthms

Question 2

biological rhythms extert an important influence on

Answer 2

the way in whih body systems behave

Question 3

biological rhythms are governed by

Answer 3

endogenous pacemakers
exogenous zeitgebers

Question 4

what are endogenous pacemakers

Answer 4

body’s internal biological clocks

Question 5

what are exogenous zeitgebers

Answer 5

external changes in the environment

Question 6

what ar eultradian rhythms

Answer 6

rhythmas that occur multiple times in teh day

Question 7

What are infradian rhythms

Answer 7

rhythms that take longer than a day to complete

Question 8

circadian rhythm is

Answer 8

rhythms that last around 24hours

Question 9

2 exmaples of circadian rhythm

Answer 9

sleep wake cycle
body temp

Question 10

the fact we feek driwsy in night time and alert in day shows the effect of

Answer 10

daylight

Question 11

daylight is an

Answer 11

importnat exogenous zeitgeber on our sleep wake cycle

Question 12

sleep wake cycle is also governed by an

Answer 12

enodgenous pacemaker

Question 13

the endogenous pacemkaer that governs the the sleep wake cycle is called the

Answer 13

suprachiasmatic nucleus (SCN)

Question 14

QWhere does the SCN lie

Answer 14

just above optic chiasm

Question 15

the optic chiasm provides info from ..

Answer 15

the eye about light

Question 16

what can reset teh SCN

Answer 16

exogenous zeitgeber

Question 17

give good q about bio clock

Answer 17

what if left to its own devices without influence of external stimuli such a slight

Question 18

Describe Siffre

Answer 18

self styled caveman that spent several extendedn periods underground to study effects on his own bio rhythms

Question 19

what was the conditions in the cave

Answer 19

deprived of xp to natural light and sound

but accessto adequate food and drink

Question 20

Descrbe in detail wen labri siffre emetrged from cave

Answer 20

mid sept 1962

after two months in cave of southern alps

beleived it to be mid august

Question 21

what did siffre do a decade later

Answer 21

peformed smilar event but for 6 months in a Texan Cave

Question 22

what happened in each of Siffres cave xp

Answer 22

his free running bio rhythm settled down to one

just beyond usual 24 hour (around 25)

though he did continue to fall asleep + wake up on reg schedule

Question 23

OTHER STUDY - Similar results of cave study recorded by

Answer 23

aschoff and Wever 1976

Question 24

What did aschoff and wever do

Answer 24

convinced group of pt to spend 4 weeks in WW2 bunker deprived of natural light

Question 25

what were reuslt of aschoff and wever study

Answer 25

all but one pt (whose SWC extended to 29hours) displayed circ rhythms between 24-25 hours

Question 26

Whta do both siffre xp and bunker study suggest

Answer 26

natural SWC may be slihtly longer than 24hrs but

entrained by exog zeitgebers associated with our 24hr day ( e.g # of daylight hours, typical mealtimes

Question 27

despite results of iffre xp and bunker study we shuildnt

Answer 27

overestimate influence of exog zeitgebers on our internal bio closk

Question 28

what study shws us we huldnt over estimate influence of exo zeit on our interna bio clock

Answer 28

Folkard et al studied group 12 people afgreed live in dark cabe 3 weeks

retired to bed when clock 11:45p,

rise when said 7:45 am

Question 29

what ahppened voer course of folkard study

Answer 29

researchers gradually sped up clock (pt didnt know)

ao 24hr day eventlasted 22 hours

Question 30

in folkard cve study only on ept

Answer 30

able to comfortably adjust to new routine

Question 31

what does folkard study suggest

Answer 31

exsitence of strong free-runnig circ rhythm that cant easily be overriden by exog zeitgebers

Question 32

STRENGTH - REAL LIFE APPLICATION IN CHRONOTHERAPEUTICS - Point

real world application of circ rhtym research is it has led to improvements in medical x - x - study of how timing affects drug treatments

x time pt take medi is very x as can have a x impact on treatmtent x

x right x of drug released in x area of body at x drug is most x

e.g risk of heart x greatest during x x hours after x up

therefore x medications have been developed with a x drug x x

these meds can be admin before person foes to sleep at xpm, but x drug not released till x period of x am to x (Evans and marain 1996)

shows research into circ rhytms not just x our x of human x

but research x have led to x of treatment for x wih x of conditions requiring drug x

Answer 32

real world application of circ rhtym research is it has led to improvements in medical treatments - chronotherautics - study of how timing affects drug treatments

circ rhths co ord some body basic processes e.g HR , digestion -

specific time pt take medi is very imp as can have a sig impact on treatmtent success

essential right cnoc of drug released in target area of body at time drug is most needed

e.g risk of heart attacks greatest during early morning hours after waking up

therefore chronotheraputic medications have been developed with a novel drug delivery system

these meds can be admin before person foes to sleep at 10pm, but actual drug not released till vuln period of 6 am to noon (Evans and marain 1996)

shows research into circ rhytms not just furthered our understandnig of human body

but research appl have led to imporvement of treatment for pt wih varity of conditions requiring drug therapy

Question 33

LIMITATION - Case study and small sample - POINT

Answer 33

LIMIT OF RESEARCH INTO swc is tendency to involve small groups of pt or sing indi e.g siffre

People may not be reresentative of wider pop therfore limitinf extent to which meaningful genralisation can be amd e

in latest cave xp siffre observed at age of 60 - his internal body clock ticked much more slowly than wehen he was a young man

Illustrates fcat even when same person involved , there are factors that vary that can prevent genral conc beng drawn

Question 34

strenght - shift work

provides an understanding of the x consequences that occur when they’re CR X (X)

e.g. night workers engaged in x work experience a period of reduced x around 6 in the morning (a circadian trough) meaning x and x are more likely

research has also pointed to a x between shift work and x x - shift workers are x* more likely to develop x x than people who work more x work patterns (Knutsson)

shows that research into the sleep/wake cycle may have real-world x implications in terms of how best to manage worker x

Answer 34

provides an understanding of the negative consequences that occur when they’re disrupted (desynchronisation)

e.g. night workers engaged in shift work experience a period of reduced concentration around 6 in the morning (a circadian trough) meaning mistakes and accidents are more likely (Boivin)

research has also pointed to a relationship between shift work and poor health - shift workers are x3 more likely to develop heart disease than people who work more typical work patterns (Knutsson)

shows that research into the sleep/wake cycle may have real-world economic implications in terms of how best to manage worker productivity

Question 35

counterpoitn studies investigating shift work use correlational methods

studies investigating effects of shift works tend to use x methods

so x to establish wehther x of swc is actually c casue of x effects

there may be other factors e.g high x rates in shift workers may be due to strain of x sleep and other x such as missing x x events

this suggest x factors may not create x x associated with shift x

Answer 35

studies investigating effects of shift works tend to use correlational methods

so difficult to establish wehther desynchronisation of swc is actually c casue of -ve effects

there may be other factors e.g high divorce rates in shift workeres may be due to strain of deprived sleep and other influences such as missing imp family events

this suggest bio factors may not create adverse consequences associated with shift work