exam 4 Flashcards
humans are diurnal, meaning…
we have a daily cycle that bodily systems are linked to, we are more active during the day than the night; opposite is nocturnal
circadian rhythm
behavioral, biochemical, & physiological functioning that fluctuates over a 24 hour period
internal clock
keeps circadian time; sensitive to zeitgebers which are time givers/light cues that synchronize the clock
free running rhythm
no change to external cue (light) to entrain rhythm; no zeitgebers
suprachiasmatic nucleus (SCN)
hypothalamic structure is an internal clock; lesions disrupt daily cycles in hormones, drinking, activity, etc.
optic chiasm
below the suprachiasmatic nucleus; light from the eyes directly goes to the SCN
retinohypothalamic pathway
pathway that splits off optic chiasm & innervates SCN
melanopsin
in retinal ganglion cells; light-sensitive photopigment
infradian rhythm
longer than a day; longer than circadian rhythm
ultradian rhythm
shorter than a day; shorter than circadian rhythm
circannual rhythm
occurring on an annual basis
michel siffre
French cave explorer that lived 2 months in a French cave & 6 months in a Texas cave
beta waves
shown in brain when eyes are closed to start to go to sleep; high frequency & low amplitude
alpha waves
prominent; when you become drowsy; higher frequency & greater amplitude; muscles relax, heart rate slows, etc.
stage 1 sleep
brain waves are still high frequency & low amplitude; lightest sleep & a transition into deeper sleep; start to see theta waves & vertex spikes
hypnic jerks (sleep starts)
very common (70%); muscle twitches right as you start to fall asleep; cause unknown but could be related to stress, caffeine, etc.
stage 2 sleep
entered as you fall deeper asleep; brain waves change = frequency decreasing & amplitude increasing; see sleep spindles & k complexes
slow wave sleep (stages 3 & 4)
large amplitude delta waves; synchronization of cortical activity
REM sleep
rapid eye movement; also called paradoxical sleep because body is almost paralyzed but brain is highly active; experience vivid dreams
GABA & glycine
key in REM sleep; action at ionotropic & metabotropic receptors on motoneurons; inhibition of movement
what did dr d see as his sleep paralysis demon
easter bunny
average length of sleep
varies person to person but typically 7-8 hours; sleep patterns change throughout life
sleep debt
can be developed by getting a little less sleep than needed each night; slows reaction times and results in attention deficits
1977 unique sleep study
70 year old nurse only slept for one hour every night and still cycled through normal sleep stages
jet lag
disrupts the entrainment of our biological clock
ecological niche
we sleep when we are not as adapted to avoid predators
sleep restores
helps the body repair/heal like when sick
memory consolidation
helps to consolidate memories by learning right before bed
insomnia
inability to fall asleep; wide range of causes like drugs, anxiety, etc; individual differences in expression
narcolepsy
sudden sleep attacks; frequent intense attacks of sleep for 5-30 minutes
cataplexy (REM)
sudden loss of muscle tone; usually accompanies narcolepsy; hypnogogic & hallucinations
sleep walking (somnambulism)
occurs in deepest stage of non-REM sleep; more common in childhood than adulthood; can be hereditary; causes include sleep apnea, alcohol, restless leg syndrome, etc.
hypocretins/orexins
neuropeptides associated with controlling transitions between sleep states
can dogs have narcolepsy
yes; certain dogs exhibit a mutant gene for hypocretin receptor 2
sleep paralysis
muscle atonia & dreaming while awake; common with 1/3 of students
sleep behavioral disorder
lack of muscle atonia while in REM
is the brain active during slow wave sleep
yes; shown in PET scans
how many people are affected by schizophrenia
about 2.4 million/1% of population
onset of schizophrenia
men: late teens-early 20s & women: mid 20s-early 30s; seldom occurs after 45 or before puberty
heritability
70-80% of heritability for schizophrenia; multiple genes play a role
eye tracking
non invasive way to look for schizophrenia; lack of smooth pursuit & very erratic; deficits in areas V5 & MT
ventricular enlargement
abnormality shown in schizophrenia; specifically lateral ventricles; tied to the DISC1 protein (developmental)
how are the hippocampus and amygdala in a schizophrenic brain
smaller than usual
corpus callosum in schizophrenia
differs in function; less efficient transfer of activity
frontal lobe in schizophrenia
activity is decreased compared to typical brain
wisconsin card sorting task
non invasive way to assess schizophrenia and brain activity
chlorpromazine
“lobotomy in a bottle”; neuroleptic; antagonizes dopamine, serotonin, histamine, adrenaline, & acetylcholine receptors; action at D2 receptor
what is dr d doing for easter
he doesn’t like bunnies that much
overactive dopamine system
underlies schizophrenia; neuroleptics/antipsychotics are active at D2 receptor - direct correlation with effective dose; higher affinity = lower dose
phencyclidine (PCP)
produces positive & negative “schizophrenia like” symptoms; chronic use can lead to “schizophrenia like” states
major depressive disorder/clinical depression
sever symptoms that affect how you feel, think, & handle daily activities; symptoms must be present for 2 weeks
persistent depressive disorder (dysthymia)
present for at least 2 years
perinatal depression
either during pregnancy or postpartum
psychotic depression
also exhibit some form of psychosis like delusions or hallucinations
seasonal affective disorder (SAD)
onset of depression during winter months with less natural sunlight
difference in depressed brain activity
greater activation in prefrontal cortex & amygdala (can persist after depression is gone); decreased activation in parietal & posterior temporal cortices and anterior cingulate
