Biological Rhythms

Question 1

Bio rhythms

Answer 1

Distinct patterns of changes in body activity that repeat regularly + conform to cyclical time periods (24 hours)

Question 2

Influence on bio r

Answer 2

Internal body clocks = endogenous pacemakers
External body = exogenous zeitbergs - which entrain bio rhythms (natural light)

Question 3

Circadian rhythm

Answer 3

Bio rhythms that have frequency of around one each 24 hours + the duration is about 24 hours e.g sleep/wake cycle

Question 4

Infradian rhythms

Answer 4

Bio rhythms that have a frequency of less than one cycle per 24 hours or a duration of more than 24 hours e.g menstruation + seasonal affective disorder

Question 5

Ultradian rhythms

Answer 5

Bio rhythms that have frequency of more than one cycle per 24 hours or a duration of less than 24 hours e.g stages of sleep where there r repeating stages of light + deep sleep

Question 6

SCN

Answer 6

The suprachiasmatic nuclei + sleep wake cycle
-master circadian endogenous pacemakers
-tiny bundle of nerve cells ordered in hypothalamus in each hemisphere - directly above optic chaism

Question 7

Pineal gland in dark/sleep

Answer 7

Produce melatonin

Question 8

Pineal gland wake/daily

Answer 8

Inhibit melatonin
Light = exogenous zeitgberger

Question 9

Folkard evidence

Answer 9

Found kids who had stories read to them at 3pm showed superior recall + comprehension offer a week compared to kids who heard stories at 9am

Question 10

Michel siffre cave study

Answer 10

• wanted to observe rhythms of brain even though no natural day light to guide body clock - wanted to see if theor was a strong internal body clock
• cave - no daylight/clock/radi, woke, ate and slept when felt like it
• found body preffered a 25 hour cycle beyond usual 24 hour so maybe natural body clock should operate on 25 hour cycle
  He also lost sense of time believing he had one month left to go

Conc:
Demonstrated free running internal body clock that operated independently of natural day/light cycle

Question 11

Exogenous zeitgebers

Answer 11

External cues that influence bio rhythms e.g saylight influences the sleep-wake cycle

Question 12

Endogenous pacemakers

Answer 12

Internal ‘clocks’ that regulate bio rhythms e.g suprachiasmatic nucleus scn