07 - NS Org & Function of Limbic System Flashcards
Gyri
hills
Sulci
grooves
1’ motor cortex
cell bodies of motor neurons
precentral gyrus
1’ sensory cortex
sensations from body being processed (skin, muscle, joint)
post central gyrus
Identify the deep grooves that seperate the hemispheres and some lobes of the brain
longitudinal fissure
central sulcus
lateral fissure
Homonculus
more sensory and motor cortical neurons dedicated to the upper and lower limbs than the trunk
somatosensations
touch, pressure, proprioception, pain, temperature
parietal lobe
somatosensory cortex
association cortex
common integrative area
frontal eye field
voluntary scanning movements
frontal lobe
primary motor
premotor cortex
intellect
occipital lobe
visual cortex
association cortex
temporal lobe
auditory cortex
association cortex
limbic system
broca’s area and wernicke’s area
b: patterns and routines
w: for deciphering
= speech
Identify 1’ auditory cortex, 1’ visual cortex
a: temporal lobe
v: occipital lobe
insular cortex
balance
emotional context to sensation
(good pain, bad pain)
1’ gustatory cortex
taste chemoreception
food preference
olfaction
smell
right hemisphere
- movements of left side
- sensations from left side
- spatial orientation and object recognition
- damage = lack of emotional context to speech
left hemisphere
- movements of right side
- sensations of right side
- spoken and written language
- damage = aphasia
- receptive (WA) can’t understand lang
- expressive (B) can’t communicate
- global (both)
lateralization
which gender is it more pronounced
males - localization of function or activity on one side of the body in preference to the other
Anterior commissure
which gender is it more pronounced
females - nerve fibers that transmit information from or to the contralateral side of the brain
Name the three white matter tracts
- commissural fibers (b/w hemispheres)
- Association fibers (w/in hemispheres)
- Projection fibers (to distant parts of the CNS)
Function of basal nuclei
- initiates and terminates motor movements
- eliminates unnecessary movements
- controls subconscious movements (arm swinging, true laughter)
- starts/stops cognitive processes, attention, memory, planning and helps regulate emotional behaviours
How does the basal nuclei work
sends inhibitory information to thalamus to not make movements (movements that aren’t needed
cortex -> basal nuclei -> thalamus -> cortex
Disorders of basal nuclei
huntington’s chorea: neurodegeneration in striatum (increased movements)
parkinson’s: lack of dopamine acting on the striatum (difficulties starting/stopping movements)
Where is the basal nuclei found
- around outside of ventricles
Where is the limbic system found
- around inside of ventricles
Function of limbic system
emotion and memories and regulating behaviours
Limbic system - mammillary bodies
- olfactory relay nucleus
- emotion
LS - fornix
connects hippo to mammillary bodies
LS - hippocampus
what and location
- who what when why
- long term memory formation
(converts st to lt) - located in medial temporal lobe
LS - amygdala
- analyses anger and fear expressions
- assesses danger and elicits fear response (fight or flight)
- emotional memories
- output to hypothalamus
Damage to amygdala
Abnormal activation
- inability to recognize fear in other people
- lack of fear
- loss of inhibition
- impaired emotional memories
- panic disorder
- PTSD
- GAD
how is information delivered in the limbic system
info from hippocampus & amygdala -> fornix -> mammillary bodies -> thalamus (through mammillothalamic tract) -> prefrontal cortex & cingulate cortex (gyrus) (through thalamic tract)
PFC
regulates attention/importance
Cingulate cortex
- major connecting hub between cerebral cortex and limbic system
- reality check
anterior thalamic nuclei
- alertness
- importance
entorhinal cortex
- input/output for hippocampus
- spacial GPS map
What are the two types of amnesia
examples
anterograde amnesia: deficit in the ability to form new memories following the time of brain injury (no effect on intellectual or perceptual function)
- hippocampal atrophy (loss of dendrites)
retrograde amnesia: loss of long-term memories
- alzheimer’s disease (neurofibrillary plaques and tangles)
Why can anterograde and retrograde amnesia occur independently
anterograde: inner arc
retrograde: outer arc
Declarative memory
short-term (acquisition and short-term storage)
- medial temporal lobe (thalamus, amygdala, hippocampus
long-term (long-term storage)
- neocortex
non-declarative
procedural (acquisition and long-term retenation)
- cerebellum and basal ganglia
What is procedural memory
long-term memory involved in the performance of different actions and skills
vision, balance, position -> cerebellum -> thalamus -> premotor cortex
Early experience -> basal nuclei -> thalamus -> premotor cortex
