Chapter 8.1 Flashcards
Early psychologists believed that cycles of wakefulness and sleep were dependent upon e……. S……
Curt richter in 1922 proposed that the body generates its own cycles of a……. And i………
External stimuli
-stay away from predators
Activity and inactivity
Some animals generate e……… C……… R……, internal mechanisms that operate on an annual or yearly cycle
-birds migratory patterns, animals storing food for the winter
Endogenous circANNUAL rhythms
All animals produce e……… C…….. R……, internal mechanisms that operate on an approximately 24 hour cycle
- sleep cycle
- frequency of eating and drinking
- body temperature
- secretion of hormones
- urination
- sensitivity to drugs
Endogenous circADIAN rhythms
Setting and resetting the biological clock
1) The purpose of the circadian rhythm is to keep our i……. workings in phase with the outside world
2) The human circadian clock generates a rhythm slightly longer/shorter than ?? hours when it has no e……. Cue to set it
3) resetting our circadian rhythms is/isn’t necessary sometimes
1) internal
2) longer, 24, external
3) is sometimes necessary
Setting and resetting the biological clock
Zeitgeber: German meaning “t… G….”
-refers to the s……. That resets the c…….. R…..
- examples=sunlight, exercise, meals, arousal of any kind, temperature of environment, etc.
- depression, irritability, and impaired job performance are effects of using something other than s……. As a zeitgeber
“Time giver” refers to the stimulus that resets the circadian rhythm
Depression…. Using something other than sunlight as a zeitgeber
Jet Lag
Refers to the disruption of the c…….. R……. Due to the crossing of t… z….
- stems from a mismatch of the internal c…….. C…. And the e……. Time
- sleepiness during the day, sleeplessness at night, and impaired c…………
Traveling w… “P….-d…..” Our c…….. R……
Traveling e… “Phase-a…….” Our c…….. R……
Disruption of the circadian rhythms due to crossing time zones
Mismatch of the internal circadian clock and external time
Impaired concentration
West= “phase delays” in our circadian rhythms
East= “phase advances” in our circadian rhythms
Shift work
Sleep duration depends on when one goes to s….
Working at night does not reliably change the c…….. R…..
-not full spectrum lighting!
People adjust best to night work if they sleep in a very dark room during the day and work under very bright lights at night
Sleep
Circadian rhythm
Morning people and evening people
Cycles can differ between people and lead to different patterns of w………. And a……..
Changes as a function of age:
- young children are m…… People
- adolescents are often n…. People
As an adult, it partially depends upon g…….
Wakefulness and alertness
Young are morning people, adolescents are night people
Genetics
Mechanisms of the biological clock
Mechanisms of the circadian rhythms:
- the suprachiasmatic n……
- genes that produce certain p…….
- m…….. Levels
- the suprachiasmatic NUCLEUS
- genes that produce certain PROTEINS
- MELATONIN Levels
The Suprachiasmatic Nucleus (SCN)
-supra=over or on top of a structure
1) The main control center of the circadian rhythms of s…. And t……….
- located above the o…. Chiasm and part of the h………..
2) damage to the SCN results in less consistent body rhythms that are no longer synchronized to e………… Patterns of L…. And d…
- external light stimulation
1) sleep and temperature
- optic, hypothalamus
2) Environmental patterns of light and dark
The Suprachiasmatic Nucleus (SCN) and the Circadian Rhythm
1) generates circadian rhythms in a g………. Controlled, un……. Manner
2) single cell extracted from the SCN and raised in tissue culture continues to produce a….. P…….. In a R……. Pattern
3) various cells communicate with each other to s…… The circadian rhythm
1) genetically controlled, unlearned manner
2) action potential in a rhythmic pattern
3) sharpen
The Suprachiasmatic Nucleus (SCN) and the Retinohypothalamic Path
1) L…. resets the SCN via a small b….. of the optic nerve known as the Retinohypothalamic path
- travels directly from the R….. To the SCN
2) the Retinohypothalamic path comes from a special population of g……. Cells that have their own photop…… called melano….
- the cells respond directly to L…. And do not require any i…. From the R… Or c….
1) light, small branch
- retina
2) ganglion cells, photopigment called melanopsin
- respond directly to light and don’t require any input from the rods or cones
The biochemistry of the circadian rhythm
1) two types of genes are responsible for generating the c…….. Rhythm
- p…..: produce proteins called PER
- t…….: produce proteins called TIM
2) PER and TIM proteins increase the activity of certain kinds of n…… In the SCN that regulate s…. and w…..
- mutations in PER gene result in odd circadian rhythms of decreased a…….. If deprived of a good nights sleep
1) Circadian rhythm
- period
- timeless
2) neurons, sleep, waking
- alertness
Melatonin
1) the SCN regulates w….. And s……. By controlling a……. levels in other areas of the brain
2) the SCN regulated the p….. Gland, an e…….. Gland located posterior to the thalamus
3) the pineal gland secretes m…….., a hormone that increases s………
1) waking and sleeping, controlling activity levels
2) pineal gland, endocrine gland posterior to the thalamus
3) melatonin, increases sleepiness
Melatonin
1) melatonin secretion usually begins ? To ? Hours before bedtime
2) melatonin feeds back to reset the b……… Clock through its effects on R…….. In the SCN
3) melatonin taken in the afternoon can p….-a…… The i……. clock and can be used as a sleep aid
1) two to three
2) biological clock, receptors
3) phase-advance, internal clock
