7 Cortex I Flashcards
What is a clinicoanatomical correlation?
Correlating a lesion observed at autopsy with premortem clinical signs to infer function
What area of the cortex was the first to be formulated using clinicoanatomical correlation?
Broca’s area
Where is Broca’s area located and what is its function?
inferior frontal convolutions; language expression
What is the most common type of neuron in the cerebral cortex?
pyramidal cells
Name the six layers of the cortex.
I. Plexiform II. outer granular III. outer pyramidal IV. inner granular V. inner pyramidal VI. multiform
What are the horizontal fibers in layers IV and V of the cortex called?
Band of Baillerger
What do you call the interneurons that make connections between layers and within layers of the cortex?
Granule cells
In which layers of the cortex can you find pyramidal cells?
All layers except layer I, predominant in layers II, III, and V
Are granule cells usually inhibitory or excitatory?
inhibitory
Which layer(s) of the cortex do interhemispheric arise from and what do they form?
Layer III, corpus callosum and anterior commissure
Which areas of the cortex does the corpus callosum connect?
all areas except the temporal poles, which are connected by the anterior commissure
What are the two types of intrahemispheric axons?
long association and short association axons
Which layer(s) of the cortex do long association axons arise from and what do they connect?
layers III and V; they connect lobes
Which layer(s) of the cortex do short association axons arise from and what do they connect?
layer II; they connect gyri
What do local intrinsic axons connect?
they connect cortical layers together
What do local circuit axons connect together, and what makes them chemically unique?
they connect columns; they are typically peptidergic
what is the difference between corticofugal and corticopetal axons?
corticofugal axons originate in the cortex and end in other subcortical brain sturctures, whereas corticopetal originate in subcortical structures and end in the cortex
what are the different divisions of projection/corticofugal axons?
corticothalamic, corticobulbar, corticospinal, corticostriate, corticopontine
Which layer(s) of the cortex do corticothalamic axons arise from?
layer VI
Which layer(s) of the cortex do corticobulbar and corticospinal axons arise from?
layers III and V
Which layer(s) of the cortex do corticostriate and corticopontine axons arise from?
V
What happens in the first half of gestation in regards to brain development?
formation of the cortical plate and of all cortical neurons
what are the components of the undeveloped or undifferentiated part of the telencephalic neural tube?
a plexiform zone and a layer of neuroblasts known as the matrix zone or ventricular zone
What event triggers neuroblast migration into the plexiform zone during neural development?
the arrival of noradrenergic axons in the plexiform zone
