10a: Cortex I (Architectonics) Flashcards
The limbic lobe includes which structures? Star the one that encircles (X).
- Cingulate gyrus*
- Parahippocampal gyrus*
X = diencephalon
Cortex surface area is greatest in (mouse/monkey/human).
Human
The cerebral cortex can be separated into which basic type(s)? List the most abundant of these.
- Neocortex*
2. Allocortex
In humans, the neocortex accounts for (X)% of the cortex.
X = 90
Neocortex has how many layers?
6
T/F: Both allocortex and neocortex have 6 layers of nerve cells.
False - allocortex has less
Hippocampus is considered (neocortex/allocortex).
Allocortex
Most abundant cell type in cerebral cortex is (X), primarily found in which layer(s) of neocortex?
X = pyramidal cells;
Layers 2, 3, 5, 6
The long, (ascending/descending) apical dendrite of (X) cell passes through cortex to reach layer (Y) and form its apical (Z).
Ascending;
X = pyramidal;
Y = 1
Z = tuft
In pyramidal cells, (apical/basal/both/neither) dendrites are covered in dendritic spines.
Both
T/F: Pyramidal cells are main projection neurons of cerebral cortex.
True
Pyramidal cells of cortex have (X) number of axons, with extensive (Y) to contact neurons in (adjacent/subsequent) cortical columns.
X = 1
Y = collateral arbors;
Adjacent (within same cortical area)
Pyramidal cells are (excitatory/inhibitory) and use which NT(s)?
Excitatory;
Glu (primarily) and some Asp
(X) cells are just like pyramidal cells, but lack (Y). They’re (excitatory/inhibitory).
X = spiny stellate;
Y = apical dendrites;
Excitatory
T/F: Spiny stellate cells lack dendritic spines.
False - possess many dendritic spines
The non-pyramidal (excitatory/inhibitory) neurons in cortex primarily use which NT(s)?
Inhibitory;
GABA
Non-pyramidal neurons are found in which layer(s) of cortex?
All
(Pyramidal/non-pyramidal) cells are referred to as “local circuit” neurons and make up about (X)% of neuronal population in cerebral cortex.
Non-pyramidal;
X = 20
Many (pyramidal/non-pyramidal) cells also contain peptides and (X)-binding proteins.
Non-pyramidal;
X = Ca
(X) stain shows characteristics of cell bodies within cerebral cortex.
X = Nissl
Neocortex Layer 1, aka (X) layer, contains primarily (Y) with (few/many) neurons.
X = molecular;
Y = apical tufts of pyramidal cells (and axons that they terminate on);
Few
Neocortex Layers 2/3 contain predominantly (small/large) (X) cells.
Small and medium;
X = pyramidal
Neocortex Layer 4 characterized by (X) cells.
X = small spiny stellate or pyramidal
Neocortex Layer 5 characterized by (X) cells.
X = large pyramidal
Neocortex Layer 6A characterized by (X) cells.
X = small or medium pyramidal
Neocortex Layer 6B characterized by (X) cells.
X = horizontal
Which layer of neocortex receives main input from thalamus?
Layer 4
T/F: There are variations in layering pattern throughout the cortex. Some layers can be more/less prominent in certain areas.
True
In (X) areas, the (small/large) neurons of Layer 4 are particularly prominent. The cortex is referred to as (Y) in these areas.
X = primary sensory;
Small;
Y = granular cortex
(X) areas lack a prominent Layer 4. These areas of cortex are referred to as (Y).
X = motor cortex; Y = agranular
In cortical areas with neurons that project long distances, (X) cells in Layer (Y) may be very (small/large). Give an example.
X = pyramidal;
Y = 5
Large;
Precentral gyrus/primary motor cortex (Betz cells very large)
(X) stain shows axon bundles that radiate through cortex.
X = Myelin (i.e. Weigert)
Myelinated axons are arranged in (vertical/horizontal) bands.
Both
Somatosensory cortex occupies which Brodmann areas?
1, 2, 3
Motor cortex occupies which Brodmann areas?
4
Primary visual cortex occupies which Brodmann areas?
17
Auditory cortex occupies which Brodmann areas?
41, 42
In order for cortical area to be considered “distinct”, the region must have distinct:
- Cyto/myelo-architectonics
- Connections
- Function
Most synapses formed in cerebral cortex come from (extrinsic/intrinsic) neurons.
Intrinsic
Information analyzed by cortex comes from (extrinsic/intrinsic) sources and is nearly all (excitatory/inhibitory).
Extrinsic;
Excitatory
List the sources of input to the cerebral cortex.
- Thalamus
- Other cortical areas
- Callosal/commissural input
T/F: Thalamus sends input only to layer 4 of neocortex.
False - layers 3 and 6 also
The (excitatory/inhibitory) input from thalamus to cortex terminates on which cell type(s)?
Excitatory;
- Pyramidal
- Inhibitory (non-pyramidal)
“Association input” to cortex, from (X) areas, terminates primarily in which layer(s) of neocortex?
X = other cortical;
Layer 3 (and some feedback to layer 1)
“Callosal input” to cortex terminates primarily in Layer (X) of neocortex and send efferents that arise form Layer (Y) of neocortex.
X = Y = 3
T/F: All cortical areas give rise to and receive callosal connections.
False
Feedback to Thalamus primarily arises from (pyramidal/non-pyramidal) cells in Layer (Y) of neocortex.
Pyramidal;
Y = 6
