Biopsych -> Biological Rhythms Flashcards
Biological Rhythms
Biological rhythms are cyclical changes in physiological systems. They evolved because the environments in which organisms live have cyclical changes. There are three types of biological rhythms
Circadian Rhythms
24 hours
suprachiasmatic nuclei (SCN)
pacemaker
synchrony
photo entrainment
coordinate activity
The Sleep-Wake Cycle
external signals
different times of the day
2:00-4:00am and 1:00-3:00pm
melatonin
homeostatic control
daylight
internal circadian rhythm
Strengths of circadian rhythms
Chronotherapeutics
Medication times
Heart attacks
Weaknesses of circadian rhythms
Arctic region
Exogenous zeitgebers
&
Individual differences
Ultradian Rhythms
less than 24 hours
(REM) sleep and (NREM) sleep
distinct EEG pattern
Basic Rest Activity Cycle (BRAC)
state of alertness into a state of physiological fatigue
loss of concentration, fatigue and hunger
Strength of ultradian rhythms
Elite violinist
90 minutes
BRAC
Weakness of ultradian rhythms
Individual differences
Biologically determined
Infradian Rhythms
longer than 24 hours
menstrual cycle
variations in the length
Hormones regulate the menstrual cycle Ovulation
progesterone levels
Strength of infradian rhythms
Affect behaviour
Facial preferences
Weakness of infradian rhythms
Menstrual cycles synchronise
Sweat
Pheromones
Endogenous Pacemakers
SCN
hypothalamus
circadian rhythms
time-coordinated signals
external light levels change
optic nerve
melatonin
promote wakefulness.
Strengths of Endogenous Pacemakers
No access
Core temperature rhythm
Weakness of Endogenous Pacemakers
Sleep-wake cycle extended
Need exogenous zeitgebers
Exogenous Zeitgebers
outside of the organism
light
SCN
body’s organs and glands
24-hour cycle
melanopsin
endogenous pacemakers
out of synchrony
disrupted sleep patterns, increased anxiety and decreased alertness And vigilance
Strength of Exogenous Zeitgebers
Blind people
Light perception
&
Exposure to bright light
Easy-wear flights
Weakness of Exogenous Zeitgebers
Arctic regions
Normal sleeping patterns
