biological rhythms: circadian rhythms

Question 1

biological rhythms

Answer 1

-cyclical chnages in body activity. have evolved as a result of enviromental influences (endogenous pacemakers- internal + exogenous zietgebers-extrenal)

Question 2

circadian rhytms

Answer 2

-24 hours
-type of biological rhythm in which a pattern of behvaiour occurs or recurs approx. every 24 hrs + which is set + reset by enviromental light levels
-sleep/wake cycle, body temp

Question 3

suprachiasmatic
SCN

Answer 3

-structure found in hypothalamus + known as ‘master clock’-endogenous pacemaker
-recieves info on light via eyes+ optic nerves
-uses this info to reset diff cycles

Question 4

body temp

Answer 4

-lowest in morning + highest in early evening
-rise in body temp allows us to become more alert + helps to wake ys up
-varies by around 5’c over 24 hours

Question 5

siffres cave study (1975)

Answer 5

-what happen to cr if cut of from zeitgebers + had to rely on EP to eat + sleep
-he spent 6 months in cave in texas + monitored by phone + videos
-he had erratic s/w at first but settled to average of 25 hrs instead of 24
-we have internal mechanism that regulates s/w cycle but shifts length to 25 hrs if we have no EZ to reset it

Question 6

ao3

strengths
Baraldo 2008-drugs

Answer 6

-pharmacokinetics: (action of drugs on body)theres certain peak times when drugs most likely effective.led to the development timing of drug dosing for meds including:

anitcancer, cardiovascular, respiratory, anti ulcer and anti epileptic drugs (Baraldo 2008)

Question 7

strengths

Answer 7

-undertsnading of consequences as a result of cr disruption- desynchronisation
-bolvin (1996) night workers experience period of reduced concentration around 6am so mistakes more liekly
-knuston (2003) link between shift work + poor health. shifts workers 3x more likely to develop heart disease (bad sleep/ stress adjusting s/w cycle)

Question 8

weakness

Answer 8

-studies of s/w small samples (siffres=case study) so unrepresentative of wider population. in his recent studies (60yrs) his internal clock clicked slower then his youth
-still had artifical light. czeiser (1999) able to adjust ppts cr from 22 to 28hrs using dim light

Question 9

weakness

duffy 2001

Answer 9

-indivual differences some 13-65 hrs(czeiser 1999)
-duffy: some ppl display a natural preference for going bed early+ rising early + some prefer opposite