Save
...
Paper 2
Biopsychology
Biological rhythms
Save
Share
Learn
Content
Leaderboard
Share
Learn
Created by
Eujean Mangdao
Visit profile
Cards (16)
Biological rhythms
?
Cyclical
changes in the way that biological systems behave
Have evolved due to the
environment
in which
organisms
live have cyclic changes
E.G.
day/night
,
summer/winter
etc.
Circadian rhythms
?
A pattern of behaviour that occurs or reoccurs approx. every
24 hours
, and which is set or reset by the
environmental
light levels
Sleep-wake cycle
?
Refers to alternating states of sleep and waking that are dependent on the 24 hour
circadian
cycle
is an example of circadian rhythms
How do
circadian rhythms
work?
-Light provides primary input into the system
-->first detected by the eye, which sends messages to the
suprachiasmatic nuclei
(SCN) found in the
hypothalamus
-The SCN uses this info to coordinate the activity if the entire circadian system
-Sleeping + wakefulness are not determined by the circadian rhythm alone, but also by
homoeostasis
Endogenous
pacemakers
?
-Internal mechanisms/cues
-e.g.
body clocks
-Regulate biological rhythms
Exogenous
Zeitgebers
?
-
External
cues
-e.g.
social cues
, light
-Environmental events that are responsible for resetting the
biological clock
--
Regulate
biological rhythms
The
SCN
+
pineal gland
work together as
endogenous
pacemakers; however, their activity is
responsive
to external cues of light (
EX Z
)
SCN
?
-Found in the
hypothalamus
-Closely linked to the
pineal gland
-->responsible for the release of
melatonin
-Known as the
master clock
-Receives info about light (EX Z) via the
optic nerve
-->sends signals to t he pineal gland which increases melatonin
Light levels -> Eyes (optic nerve) -> Brain ->
SCN
(hypothalamus) ->
Pineal gland
->
Melatonin
-> Sleep-wake cycle
Case study
-
Siffre's
cave study?
-Spent long period of time (2 + 6 months) in dark caves to examine the effects of
'free running'
/'body clock' biological rhythms
-In each case, Siffre's free running
circadian rhythm
settled down to just above the usual
24
(about
25
hours)
-He DID have a regular sleep/wake cycle
Infradian
rhythms?
Biological rhythms
that occur less often than once a day, meaning the cycle periods are a lot longer than 24 hours
->e.g.
Menstrual cycle
,
SAD
Menstrual cycle
?
-Female menstrual cycle that is approximately
28
day with consideration of variation of
23-36
days
-Regulated by
hormones
and can be affected by stress and excessive exercise
-Ovulation occurs roughly halfway through the cycle when
estrogen
levels are highest
-After
ovulation
,
progesterone
levels increase, ready for possible embryo plantation
Seasonal affective disorder
(
SAD
)?
-An
infradian
rhythm related to the seasons (yearly cycle)
-
Melatonin
is secreted by the
pineal gland
at night, therefore longer nights increase melatonin secretion
-Linked to an increase in depressive symptoms
Ultradian rhythms?
Biological rhythms that occur more often than
24 hours
, meaning the cycles are shorter than 24 hours
->e.g. human sleep patterns, meal patterns, hunger/appetite
What are the different stages of
human sleep patterns
?
4-5%
,
light sleep
with muscle activity slowing down
45-55%, Breathing patterns and heart rate slows, decrease in body temperature
4-6%
, Deep sleep, brain begins to generate, slow
delta waves
12-55%
, Very deep sleep, rhythmic breathing, limited muscle act
20-25%
, Rapid eye movements,
brain waves
speed up + dreams occur, muscles relax + heart rate increase, breathing is rapid
Appetite/meal patterns?
-
Ultradian rhythm
-Most
humans
eat 3 meals a day + appetite rise + fall because of food consumption
See similar decks
Biological rhythms
Psychology > Paper 2 > Biopsychology
26 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
26 cards
Circadian Rhythms
Psychology > Paper 2 > Biopsychology
12 cards
biological rhythms
Psychology > PAPER 2 > biopsychology
25 cards
biological rhythms
psychology > Paper 2 > biopsychology
36 cards
Biological Rhythms
Psychology > Paper 2 > Biopsychology
13 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
25 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
21 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
4 cards
Biological Rhythms
Psychology > Paper 2 > Biopsychology
10 cards
biological rhythms
psychology > paper 2 > biopsychology
22 cards
biological rhythms
psychology > paper 2 > biopsychology
11 cards
biological rhythms
psychology paper 2 > biopsychology
16 cards
biological rhythms
psychology > paper 2 > biopsychology
24 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
45 cards
Biological Rhythms
Psychology > Paper 2 > Biopsychology
45 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
10 cards
Biological Rhythms
Psychology > Paper 2 > Biopsychology
5 cards
Biological rhythms
Psychology > Paper 2 > Biopsychology
7 cards
biological rhythms
psychology > paper 2 > biopsychology
128 cards
biological rhythms
psychology > paper 2 > biopsychology
20 cards