BIOLOGICAL RHYTHMS - CIRCADIAN RHYTHMS

Question 1

what 4 things must we remember for circadian rhythms?

Answer 1

biological rhythms
sleep/wake cycle
siffre’s cave study
other research

Question 2

what are biological rhythms?

Answer 2

distinct patterns of changes in body activity to cyclical time periods influenced by exogenous zeitgebers and endogenous pacemakers

Question 3

what is a circadian rhythm?

Answer 3

a biological rhythms subject to a 24 hour cycle regulating a number of body processes such as sleep/wake cycle and changes in the core body temperature

Question 4

who has biological rhythms?

Answer 4

plants animals and people

Question 5

why 2 things are biological rhythms governed by?

Answer 5

body’s internal biological clock - endogenous pacemakers

changes in the environment - exogenous zeitgebers

Question 6

what is the most important exogenous zeitgeber?

Answer 6

daylight and this is shown through how we feel drowsy when it’s night-time and alert during the day

Question 7

what is ‘free-running?’

Answer 7

if the biological clock was left to it’s own devices without the influence of external stimuli such as light

Question 8

who tried to answer the question of ‘free-running’ and conducted research?

Answer 8

Siffre

Question 9

what dud Siffre do?

Answer 9

spent several extended periods underground to study the effect of his bio rhy

Question 10

what was siffre deprived of, and what did he have access to?

Answer 10

deprived of exposure to natural light and sound

access to adequate food and drink

Question 11

how long did he spend in first 2 studies in the cave?

Answer 11

1. 2 months in the cave of the alps

2. 10 years later, performed similar test for 6 months in a Texan cave

Question 12

what happened in both of Siffre’s experiments?

Answer 12

‘free-running’ biological rhythm settled down to 25 hours though he did continue to fall asleep and wake on a regular schedule

Question 13

who found similar results to Siffre?

Answer 13

Aschoff and Wever

Question 14

what did Aschoff and Wever do?

Answer 14

ppts spent 4 weeks in WWII bunker w/ no natural light

Question 15

what were the findings of Aschoff and Wever experiment?

Answer 15

all but 1 ppts had circadian rhythm of 25 hrs, one had 29 hrs

Question 16

what do Siffre’s and Aschoff and Wever’s study show?

Answer 16

‘natural’ sleep/wake cycle could be longer than 24 hours, but trained by exogenous zeitgebers associated w/ 24 hrs day

Question 17

who studied exogenous zeitgebers?

Answer 17

Folkard et al

Question 18

who did Folkard et al study and what did they do?

Answer 18

12 ppl who agreed to live in a dark save for 3 weeks, went o be at 11:45 and waking up at 7:45

Question 19

what did researchers to over the course of Folkard’s study?

Answer 19

gradually speeded up the clo9ck so the 24 hr day was eventually 22 hrs

Question 20

what were the findings of Folkard’s study and what does this suggest?

Answer 20

only 1 ppt adjusted by to the new regime , suggested the existence of a strong free-running circa rhy cannot be easily overridden by exogenous zeitgebers

Question 21

give 3 evaluations points for circadian rhythms?

Answer 21

+ practical application to shift work
+ practical application to drug treatments
- use of case-studies and small samples

Question 22

a strength of circadian rhythms is that it has good practical application to…

Answer 22

shift work

Question 23

what does knowledge about circadian rhythms given researchers a better understanding of?

Answer 23

adverse consequences that can occur as a result of their disruption known as desynchronization

Question 24

what did Boivin et al find that shows affects of shift work?

Answer 24

night workers engaged in shift work experience a period of reduced concentration around 6 in the morning, a circadian trough that makes mistakes and accidents more likely

Question 25

who conducted research to suggest a relationship between shift work and poor health?

Answer 25

Knutsson

Question 26

what did Knutsson find?

Answer 26

shift workers are 3+ x likely to develop heart disease due to stress of adjusting to different sleep/wake cycles and poor quality of sleep throughout the day

Question 27

therefore, practical application for circadian rhythms to shift work has…

Answer 27

economic implications in terms of how best to manage worker productivity

Question 28

circadian rhythms also has high practical application for ____ _________

Answer 28

drug treatments

Question 29

what do circa rhythms cooridnate that has an effect on…

Answer 29

number of body’s basic processes e.g heart rate, digestion and hormone levels having an effect on pharmacokinetics

Question 30

what are pharmacokinetics?

Answer 30

the action of drugs on the body and how well they are absorbed and distributed

Question 31

what does research into circadian rhythms reveal about drug treatments?

Answer 31

there are certain peak times during the day or night where drugs are likely to be at their most effective

Question 32

what does circadian rhythms led to the developemnt of in drug treatments?

Answer 32

guidelines to do with the timing of drug dosing for a range of medication such as anti-cancer, cardiovascular, respiratory etc [ baraldo ]

Question 33

a weakness of circadian rhythms is that…

Answer 33

studies of sleep/wake cycle involve small groups of ppts

Question 34

what are ppts to representative of?

Answer 34

the wider population and limits the extent of menaingful generalisation

Question 35

what does that even when the same person is studied there are factors that prevent general conc?

Answer 35

siffre most recent exp at age 60 shows his internal clock was slower than when he was a young man