10a: Cortex I (Architectonics)

Question 1

The limbic lobe includes which structures? Star the one that encircles (X).

Answer 1

1. Cingulate gyrus*
2. Parahippocampal gyrus*

X = diencephalon

Question 2

Cortex surface area is greatest in (mouse/monkey/human).

Answer 2

Human

Question 3

The cerebral cortex can be separated into which basic type(s)? List the most abundant of these.

Answer 3

1. Neocortex*

2. Allocortex

Question 4

In humans, the neocortex accounts for (X)% of the cortex.

Answer 4

X = 90

Question 5

Neocortex has how many layers?

Answer 5

6

Question 6

T/F: Both allocortex and neocortex have 6 layers of nerve cells.

Answer 6

False - allocortex has less

Question 7

Hippocampus is considered (neocortex/allocortex).

Answer 7

Allocortex

Question 8

Most abundant cell type in cerebral cortex is (X), primarily found in which layer(s) of neocortex?

Answer 8

X = pyramidal cells;

Layers 2, 3, 5, 6

Question 9

The long, (ascending/descending) apical dendrite of (X) cell passes through cortex to reach layer (Y) and form its apical (Z).

Answer 9

Ascending;
X = pyramidal;
Y = 1
Z = tuft

Question 10

In pyramidal cells, (apical/basal/both/neither) dendrites are covered in dendritic spines.

Answer 10

Both

Question 11

T/F: Pyramidal cells are main projection neurons of cerebral cortex.

Answer 11

True

Question 12

Pyramidal cells of cortex have (X) number of axons, with extensive (Y) to contact neurons in (adjacent/subsequent) cortical columns.

Answer 12

X = 1
Y = collateral arbors;
Adjacent (within same cortical area)

Question 13

Pyramidal cells are (excitatory/inhibitory) and use which NT(s)?

Answer 13

Excitatory;

Glu (primarily) and some Asp

Question 14

(X) cells are just like pyramidal cells, but lack (Y). They’re (excitatory/inhibitory).

Answer 14

X = spiny stellate;
Y = apical dendrites;
Excitatory

Question 15

T/F: Spiny stellate cells lack dendritic spines.

Answer 15

False - possess many dendritic spines

Question 16

The non-pyramidal (excitatory/inhibitory) neurons in cortex primarily use which NT(s)?

Answer 16

Inhibitory;

GABA

Question 17

Non-pyramidal neurons are found in which layer(s) of cortex?

Answer 17

All

Question 18

(Pyramidal/non-pyramidal) cells are referred to as “local circuit” neurons and make up about (X)% of neuronal population in cerebral cortex.

Answer 18

Non-pyramidal;

X = 20

Question 19

Many (pyramidal/non-pyramidal) cells also contain peptides and (X)-binding proteins.

Answer 19

Non-pyramidal;

X = Ca

Question 20

(X) stain shows characteristics of cell bodies within cerebral cortex.

Answer 20

X = Nissl

Question 21

Neocortex Layer 1, aka (X) layer, contains primarily (Y) with (few/many) neurons.

Answer 21

X = molecular;
Y = apical tufts of pyramidal cells (and axons that they terminate on);
Few

Question 22

Neocortex Layers 2/3 contain predominantly (small/large) (X) cells.

Answer 22

Small and medium;

X = pyramidal

Question 23

Neocortex Layer 4 characterized by (X) cells.

Answer 23

X = small spiny stellate or pyramidal

Question 24

Neocortex Layer 5 characterized by (X) cells.

Answer 24

X = large pyramidal

Question 25

Neocortex Layer 6A characterized by (X) cells.

Answer 25

X = small or medium pyramidal

Question 26

Neocortex Layer 6B characterized by (X) cells.

Answer 26

X = horizontal

Question 27

Which layer of neocortex receives main input from thalamus?

Answer 27

Layer 4

Question 28

T/F: There are variations in layering pattern throughout the cortex. Some layers can be more/less prominent in certain areas.

Answer 28

True

Question 29

In (X) areas, the (small/large) neurons of Layer 4 are particularly prominent. The cortex is referred to as (Y) in these areas.

Answer 29

X = primary sensory; Small; Y = granular cortex

Question 30

(X) areas lack a prominent Layer 4. These areas of cortex are referred to as (Y).

Answer 30

``` X = motor cortex; Y = agranular ```

Question 31

In cortical areas with neurons that project long distances, (X) cells in Layer (Y) may be very (small/large). Give an example.

Answer 31

X = pyramidal; Y = 5 Large; Precentral gyrus/primary motor cortex (Betz cells very large)

Question 32

(X) stain shows axon bundles that radiate through cortex.

Answer 32

X = Myelin (i.e. Weigert)

Question 33

Myelinated axons are arranged in (vertical/horizontal) bands.

Answer 33

Both

Question 34

Somatosensory cortex occupies which Brodmann areas?

Answer 34

1, 2, 3

Question 35

Motor cortex occupies which Brodmann areas?

Answer 35

4

Question 36

Primary visual cortex occupies which Brodmann areas?

Answer 36

17

Question 37

Auditory cortex occupies which Brodmann areas?

Answer 37

41, 42

Question 38

In order for cortical area to be considered "distinct", the region must have distinct:

Answer 38

1. Cyto/myelo-architectonics 2. Connections 3. Function

Question 39

Most synapses formed in cerebral cortex come from (extrinsic/intrinsic) neurons.

Answer 39

Intrinsic

Question 40

Information analyzed by cortex comes from (extrinsic/intrinsic) sources and is nearly all (excitatory/inhibitory).

Answer 40

Extrinsic; | Excitatory

Question 41

List the sources of input to the cerebral cortex.

Answer 41

1. Thalamus 2. Other cortical areas 3. Callosal/commissural input

Question 42

T/F: Thalamus sends input only to layer 4 of neocortex.

Answer 42

False - layers 3 and 6 also

Question 43

The (excitatory/inhibitory) input from thalamus to cortex terminates on which cell type(s)?

Answer 43

Excitatory; 1. Pyramidal 2. Inhibitory (non-pyramidal)

Question 44

"Association input" to cortex, from (X) areas, terminates primarily in which layer(s) of neocortex?

Answer 44

X = other cortical; Layer 3 (and some feedback to layer 1)

Question 45

"Callosal input" to cortex terminates primarily in Layer (X) of neocortex and send efferents that arise form Layer (Y) of neocortex.

Answer 45

X = Y = 3

Question 46

T/F: All cortical areas give rise to and receive callosal connections.

Answer 46

False

Question 47

Feedback to Thalamus primarily arises from (pyramidal/non-pyramidal) cells in Layer (Y) of neocortex.

Answer 47

Pyramidal; | Y = 6