Cortex Flashcards
Where is the limbic system located?
Medial aspect of cerebral hemisphere
What does the limbic system regulate?
Autonomic or endocrine function in response to emotional stimuli
Also reinforces behaviour
What structures does the limbic system include?
The hippocampus, amygdala, parahippocampal gyrus, cingulate gyrus, hypothalamus and anterior thalamic nucleus
What is the Fornix?
Major output fiber bundle in the limbic system
Describe reticular formation.
Ser of interconnected nuclei located throughout the brainstem and thalamus
What descending connections does the RAS have?
spinal cord
Vasomotor, cardiac, and respiratory centers in the medulla
What are the inhibiting factors of the RAS
Brain sleep centers
alcohol and drugs
What is the non-dominant hemispheres roles?
Interpretation of tone, gestures, and ability to understand the emotional context of speech
What are the three principles of memory?
Storage
Processing
Memory traces
What are memory traces?
Chemical or structural changes that encode memory
How long does short term memory last?
Seconds to hours
How many pieces of info can we hold in our short term memory at a time?
7-8
What is the capacity of long term memory?
Limitless
What factors will affect the transfer of information from STM to LTM?
Emotional state
Rehearsal
Association
Automatic Memory
Which areas of the brain are involved in declarative memory?
Hippocampus & amygdala
Thalamus & hypothalamus
Ventromedial prefrontal cortex of the basal forebrain
What structures are involved in skill memory?
Basal ganglia/corpus striatum
Portion of brain receiving stimulus
Premotor and motor cortex
What are the seven mechanisms of memory?
Dendritic spine shape change
Extracellular proteins deposited at synapses involved in LTM
Neuronal RNA content alteration
Number and size of presynaptic terminals may increase
New hippocampal neurons appear
More neurotransmitter is released by presynaptic neurons
Which part of the brain releases acetylcholine used in declarative memory?
Prefrontal cortex and basal forebrain
In what stage of sleep are the skeletal muscles actively inhibited? Why?
REM. So we dont act out our dreams
In what stage of sleep does relaxation begin and arousal is easy? What waves are present?
NREM I
Alpha waves
In what stage of sleep is arousal more difficult and the EEG is irregular showing short high amplitude bursts?
NREM 2
In what stage of sleep do vital signs decline and sleep deepens? What waves are present?
NREM 3
Delta and theta
What stage of sleep is deep enough for parasomnias to occur and arousal is difficult? What waves are present?
NREM 4
Delta waves
Waves that are regular and rhythmic, low-amplitude, low, synchronous are best described as:
a) alpha
b) beta
c) Theta
d) Delta
Alpha
Waves that are described as rhythmic, more
irregular waves occurring during the awake and
mentally alert state are best described as:
a) alpha
b) beta
c) Theta
d) Delta
Beta
Waves that are common in children but abnormal in adults and more irregular than alpha waves are best described as:
a) alpha
b) beta
c) Theta
d) Delta
Theta
High-amplitude waves seen in deep sleep and when reticular activating system is damped are:
a) alpha
b) beta
c) Theta
d) Delta
Delta
What can cause brain waves to change?
Age
Sensory stimuli
Brain disease
Chemical state of body
What does a flat EEG mean?
Death
What is an EEG?
Electroencephalogram- Measures brain activity
What is an EEG used for?
Diagnosis and localization of:
brain lesions
tumors
infections
infarcts
abscesses
epileptic lesion
What is the difference between a grand mal and petit mal seizure?
Petit mal- mild, seen in youth, blank expression
Grand mal- loss of consciousness, bones may be broken from intense convulsions
What are the two major types of sleep?
NREM and REM
When does REM sleep occur?
After the fourth NREM stage has been achieved
What is a rolandic seizure?
seen in children 6-8
Spread of activation to motor cortex
In what stage of REM do vital signs increase? Decrease?
REM
NREM 3
Which muscles are not inhibited during REM?
Ocular muscles
True or false: In REM sleep, the EEG pattern reverts through the NREM stages to the stage 1 pattern?
TRUE
Alternating cycles of sleep and wakefulness reflect…
Natural circadian rhythm
What regulates the sleep cycle?
Nuclei of the hypothalamus
What causes narcolepsy?
Orexin receptor deficits
True or false: A normal sleep pattern alternates between REM and NREM sleep?
True
What is presumed to be the restorative stage of sleep?
Slow wave
True or false: Daily sleeping requirements decline with age?
True
What is sleep apnea?
The temporary cessation of breathing during sleep
What is insomnia?
Chronic inability to obtain the amount or quality of sleep needed
What is Narcolepsy?
Lapsing abruptly into sleep from wake state
