Limbic System Flashcards
function of the limbic system?
emotional content for learning and memory
emotional stimulus is first relayed to the __1___ and then to the ___2_____
- thalamus
2. sensory cortex
from the sensory cortex emotional stimulus then goes to the ________ and then begins cyclic interactions
cingulate cortex
feeling and bodily responses come out of the _________
- feelings from cingulate cortex
- bodily response from hypothalamus
list the 4 structures of the cyclic portion of the limbic system in order
- cingulate cortex - from sensory cortex or anterior thalamus
- hippocampus
- hypothalamus
- anterior thalamus - then back to the cingulate cortex
what is another name for the entorhinal cortex?
parahippocampal gyrus
in the circuit of papez the cingulate gyrus goes through the cingulum to the ___________
entorhinal cortex
what does the perforant path connect?
the perforant path connects the entorhinal cortex to the hippocampus
in the circuit of papez the hippocampus is connected to the mammillary body via the ________
the post commissural fibers of the fornix. it goes through the fornix
in the circuit of papez the mammillary body is connected to the anterior thalamus via the __________
mammilo-thalamic tract
in the circuit of papez the anterior thalamus is connected to the cingulate gyrus via the ___________
thalamo-cortical tract
wernicke-korsakoff syndrome affects what part of the limbic system?
the mammilo-thalamic tract of the circuit of papez (betweeen the mammillary body and the anterior thalamus)
75% of alzheimers affects what part of the limbic sysytem?
the perforant path of the circuit of papez ( in between the entorhinal cortex and the hippocampus)
what causes wernicke-korsakoff syndrome?
vitamin B1 deficiency from alcoholism
what are the symptoms of wernicke-korsakoff syndrome?
confabulation- make stuff up,
loss of memoru and ability to make new ones
where is the hippocampus located?
the temporal lobe
afferents of the hippocampus?
perforant path and fornix
intrinsics of the hippocampus?
trisynaptic ciruit
efferents of the hippocampus?
fornix (post commissural fibers)
explain the pathway of the trisynaptic circuit?
- Entorhinal cortex to the genule cells/ dentate gyrus via the perforant path
- granule cells/ dentate gyrus to the hippocampus pyramidal neurons via the missy fibers
- Ca3 to Ca1 via the schaffer collaterals or Ca3 to the fornix
what structure causes dejavou?
the Uncus over fires and by the time info comes from the perforant path to the dentate, you already have a memory.
where is the dentate gyrus located?
the hippocampus
where is the amygdala located?
anterior to the hippocampus in the temporal lobe
what are the 3 major nuclei/ divisions of the amygdala?
- basolateral complex
- cortico-medial system
- central nucleus
what are the afferents of the amygdala?
- lateral olfactory tract
2. prefrontal cortex
what are the efferents of the amygdala?
- amygdalafugal pathway
2. stria terminalis
what structure controls the fear response?
stria terminalis
what nucleus of the amygdala controls the striatial system?
central nucleus
what nucleus of the amygdala controls the olfactory system?
cortico-medial system
what nucleus of the amygdala controls the amygdalafugal pathway?
basolateral complex
what can damage to the amygdala cause?
- poorly conditioned emotional response
- poor recognition of fear
- patients fail to focus on eyes
what symptoms do psychopaths have in regard to their amygdala?
- low amygdala reactivity to emotions
- difficulty learning from punishments
amygdala hyperactivity causes?
ANXIETY
what nucleus counteracts fear?
septal nucleus
what causes kluver-bucy snydrome?
bilateral lesions to the amygdala
symptoms of kluver-bucy snydrome?
docile, overeating, hyperphagia, hyperorality, hypersexuality
left vs right amygdala when told a joke?
left amygdala - understands the joke
right amygdala - responds to the joke
loss of the the septal nucleus causes?
fear and depression
function of the septal nucleus?
counterbalance fear, pleasure, sexual gratification,
