Biopsychology bk4- Biological Rhythms

Question 1

Circadian rhythm

Answer 1

Lasts 24 hours, sleep wake cycle

Question 2

Change in temp over 24 hours

Answer 2

Temperature is normal at 37C when you wake up and peaks to 37.5C in the middle of the day. From then it decreases gradually and is at its lowest of 36C in the middle of the night.

Question 3

Changes in hormones over 24 hours

Answer 3

Melatonin stays at a low level during the day. It peaks (increases) in the night before coming back down again before you wake up.

Question 4

SCN

Answer 4

•internal clock for sleep wake cycle

• light enters eyes
• information sent via neural pathway to scn
• located in hypothalamus
• info sent to pineal gland
• pineal secretes melatonin
• sleep

Question 5

Circadian rhythm key study

Answer 5

Siffre
French cave explorer
7 months underground with no cues as to time of day
Only contact was telephone always staffed
Linked to computer and video camera to scientists on surface to monitor his physiological function and state of mind
Everyday that passed got up an hour later clock in his brain running slow
Developed 25 hour clock

Question 6

Circadian rhythm AO3

Answer 6

+ mutant hamsters
Bred mutant hamsters with 20 hour rhythm, transplanted SCN cells from mutant adult hamsters to normal hamster foetuses, born displaying the mutant 20 hour cycle. Transplanted normal SCN tissue into mutant hamsters started showing 24 hour cycle within a week
- sample biased however + scientific
+ chronotherapeutics
specific time patients take medication is important as it can have significant impact on treatment success. Essential right concentration of drug is released in target area of body at time drug is most needed. E.g. risk of heart attack more in morning, drugs took at 10pm drug isnt released until vulnerable period 6am - noon
- individual differences
Cycle length vary from 13 to 65 hours

Question 7

Infradian rhythm

Answer 7

Longer than 24 hours, menstrual cycle and hybernation

Question 8

Hormones in menstrual cycle

Answer 8

Hypothalamus controls pituitary gland.
Oestrogen is low at the start of the month and peaks in the middle then drops again.
Progesterone is low then peaks after oestrogen drops back down.

Question 9

Infradian key study

Answer 9

Sweat was collected everyday from sexually active women.
It was then smelt by female ppts daily.
The women then sinked menstrual cycles as it altered the hormone of hormone production

Question 10

Hibernation

Answer 10

Few months at a time, survival instinct

Less food in the winter, shorter colder days, lower light levels and lower temperature

Question 11

SAD

Answer 11

seasonal affective disorder
Caused by biochemical imbalance in hypothalamus due to shortening of daylight hours and lack of sunlight. Pineal gland secretes melatonin in the dark leads to sevre disruption in mood

Treatment - phototherapy, UV lifts mood significantly, serotonin levels rise

Question 12

Infradian AO3

Answer 12

+ controlled, ppt didnt meet however - limited sample , extraneous variables cant establish cause and effect
•hybernation,
Shorter colder days less food in winter, few months at a time, survival instinct
•SAD,
Caused by biochemical imbalance in hypothalamus due to lack of sunlight

Question 13

Ultradian rhythm

Answer 13

Less than 24 hours, main example is sleep