Cerebral Cortex Flashcards
what are the divisions of the cerebral cortex, and of the 3 which is most prevalent in humans
neocortex - 95 % in humans
paleocortex
archicortex
how many layers are in each division of the cerebral cortex
neocortex - 6
paleocortex - 3
archicortex - 3
what notable structure resides in the paleocortex in humans
primary olfactory cortex
what notable structure resides in the archicortex in humans
hippocampus
what is the most prevalent type of neuron in the cerebral cortex
pyramidal cell
the pyramidal cell is the principal projection neuron of the cortex, is it an inhibitory or excitatory projection
excitatory using glutamate neurotransmitter
what are dendritic spines
sites of excitatory synapses on pyramidal cell/neurons
dendritic spines can be modified as a result of learning, what does this mean ?
Minor changes in spine configuration lead to a better synapse efficiency
poor spine development is reason for some forms of intellectual disability
what are nonpyramidal cells ?
other cortical cell/neurons, make inhibitory synapses w/ GABA neurotransmitter
of the 2 types of neocortical neurons, which has long axons and which has short axons
pyramidal cell - long axons
nonpyramidal - short axons
what are the principal interneurons of the cortex
nonpyramidal cells
which layer of the neocortex would contain the most interneurons ?
granular layer
what is Focal Cortical Dysplasia
Where the arrangement of horizontal cortical layers is NOT organized during development
-results in seizures
in the primary sensory areas of the cortex, would it be composed of granular or aganular cortex
granular, b/c lots of internerurons (non-pyramidal cells)
in the primary motor cortex, would you find granular or agranular cortical regions
aganular. b/c have long axon projections of pyramidal cells
which is thicker in apperance, granular or agranular regions of the cortex ? Why ?
Agranular, b/c there are long projections (pyramidal cells)
What specific Brodmann area is known as the primary motor cortex
precentral gyrus (area 4)
what specific Broddmann are is the primary somatosensensory cortex
postcentral gyrus (area 3,1,2)
which is more constant among individuals, the total cortical volume, or specific size of Brodmann areas
total cortical volume very constant
Brodmann areas can vary b/w people
who was the famous patient who got a rod blown through his head causing left prefrontal lobe damage
Phineas Gage
what are the 4 neocortical regions in reference to function
- primary sensory
- primary motor
- association
- limbic
the sensory area of the cortex has a topographical organization, but that map has areas that are disproportionately large ? what are these areas and why are they so big ?
fingers and fovea
highly sensitive areas=larger cortex area*
in what lobe of the cortex is the primary somatosensory cortex found in
parietal lobe
what part of the parietal lobe is involved with language comprehension
inferior left parietal lobule
where is the primary visual cortex found in the cortex
banks of calcarine sulcus of the occipital lobe
bilateral injury to the inferior occipital lobe would result in _______ whereas bilateral injury to the occipital-temporal junction would result in _______
- color blindness
- motion blindness
what lobe is the primary auditory cortex located
temporal lobe
where is Wernike’s area on the cortex and what is its function ?
posterior L superior temporal gyrus
-language comprehension
where is the gustatory cortex located ?
frontal lobe and insula
where is the vestibular cortex located ?
superior temporal gyrus and post. insula
the frontal lobe of the neocortex is predominantly involved w/_________ function
motor
where is Broca’s area and what is its function?
inferior L frontal lobe (frontal gyrus)
-production of spoken and written language
what is the main function of the prefrontal cortex
executive functions like personality, foresight and insight
What is the function of the association areas
mediate higher mental functions like language, art, music
what are the 2 types of association areas
unimodal association areas
multimodal association areas
what is the function of unimodal association areas, and where are these areas located
elaborating on primary visual areas
-adjacent to visual area on occipital lobe
what is the function of multimodal association areas
high level intellectual functions
-inferior parietal lobule, temporal, and frontal lobes
what is the definition of a dominant hemisphere, and what is the dominant hemisphere in most people ?
Hemisphere that produces/comprehends language
-usually Left
Language areas usually border the Left __________ ?
lateral sulcus
why does the lateral sulcus extend further posteriorly on the left hemisphere of the cortex vs. the right
B/c planum temporale is larger on the left
how do the language areas that border the left lateral sulcus stimulate the motor cortex ?
Stimulate mouth to produce involuntary grunts
what are the two perisylvian language areas and where are they ?
Broca’s area - L inferior frontal gyrus (production)
Wernike’s area - posterior L superior temporal gyrus (comprehension)
what is aphasia and what are the two types
Inability to use language
- Fluent
- Nonfluent
Damage to Broca’s area would result in what type of apahasia
Nonfluent aphasia
-difficult to produce word, make few words and get by w/phrases
damage to Wernike’s area would result in what type of aphasia ?
Fluent aphasia
-can’t comprehend language, but can talk and write
(known as word salad)
what is the name of the area that connects Broca’s and Wernike’s areas
Arcuate fasciculus
What aspects of language are controlled in the Right hemisphere
prosody - emotional, rhythmical, emotional tone of words
allow to tell diff. b/w question and statement
what is agnosia
inability to recognizes specific things (faces, people, sounds, etc)
damage to what area of the cortex could cause agnosias ?
damage to unimodal association areas
what part of the right hemisphere produces prosody, what part comprehends prosody ?
Production - R inferior frontal gyrus
Comprehend - R posterior superior temporal gyrus
Just like Left side w/Broca and wernike areas
what part of the cortex would be injured in a patient w/contralateral neglect
R parietal lobe damage
what is apraxias, and damage to where at in the cortex could result in this
specific “lack of actions”
-result from damage to L parietal lobe
the prefrontal cortex controls executive functions, and is heavily interconnected to what thalamic nuclei
dorsomedial nucleus
what are the 2 broad types of the prefrontal cortex
dorsolateral
ventromedial
what is the dorsolateral prefrontal cortex involved in
Involved in working memory
-interconnected w/parietal association areas
damage to the ventromedial aspect of the prefrontal cortex would result in ?
- compulsive behavior
- inability to supress inappropriate responses/emotions
- **What phineas Gage had ***
what is the name of the structure that allows the R and L hemispheres to communicate with eachother
commissures
what is the largest commisure in the brain
corpus callosum
-main connection b/w hemispheres
what does the anterior commissure connect
interconnects temporal lobes
there are only 2 places in the brain that do NOT connect R and L hemispheres via the corpus callosum, what are they ?
- Hand area
- primary visual cortex
Commissures are composed of A) white matter or B)grey matter
white matter
what is alexia w/o agraphia, and what causes this ?
ability to write, but can NOT read
-caused by disconnection syndromes (hemispheres cant communicate)
what are association bundles
long white matter tracts that interconnect ares of ONE hemisphere
**DO NOT CROSS midline **
