2 & 3 FOREBRAIN/ CEREBRAL CORTEX/ THALAMUS/ INTERNAL CAPSULE

Question 1

Describe the homotypical layers of the cortex and give examples of cortex areas that are arranged in this way

Answer 1

Layer I - molecular
Layer II - External granular
Layer III - External pyramidal 
Layer IV - Internal granular
Layer V - Internal pyramidal
Layer VI - Multiform.
The association cortex's, prefrontal, parietal, temporal

Question 2

Describe the layers of the motor cortex

Answer 2

Layer I - molecular
Layer II - no cells
Layer III - Big pyramidal cells
Layer IV - no cells
Layer V - giant pyramidal cells
Layer VI - Some pyramidal cells

Question 3

Describe the layers of the somatosensory cortex

Answer 3

Layer I - molecular
Layer II - granular cells
Layer III - no cells
Layer IV - lots of granular cells
Layer V and VI - no cells.

Question 4

What divides the allo cortex from the neocortex

Answer 4

The rhinal or collateral sulcus

Question 5

Describe pyramidal cells

Answer 5

Large cells, triangular base. Long apical and basal dendrites. Also known as efferent or Golgi Type I cells. Involved in output info to other regions e.g. thalamus, basal ganglia, down spine

Question 6

Describe granular cells

Answer 6

Round cells with short axons. Also known as local circuit neurons of Golgi type II. They talk to adjacent neurons and process sensory information. Are interneurons

Question 7

How many layers does the allo cortex have

Answer 7

3

Question 8

How many layers does the neocortex have

Answer 8

6

Question 9

In what cortex layer are commissural and association fibres found

Answer 9

Layer III, external granular

Question 10

What layer are projection fibres found and where do they go to

Answer 10

Layer V, internal granular. Project to subcortical structures

Question 11

What layer are specific afferent fibres found and describe

Answer 11

Layer IV, internal granular. E.g. from thalamic relay nuclei

Question 12

Describe the function of the thalamus

Answer 12

An area of the brain that determines what sensory signals go to and from the cortex. The thalamus is organised into regions that have specific jobs, e.g. all cortical areas are represented in the thalamus.
There are afferent and efferent fibres in the thalamus so the thalamus can modulate sensory input to the cortex (i.e. blocking out some sensory inout to cortex as well as delivering it)

Question 13

What are the relevant (to this paper) areas of the thalamus

Answer 13

Ventral Anterior nucleus, ventral lateral nucleus, ventral posterior nucleus, lateral geniculate body and medial geniculate body.

Question 14

What is the medial geniculate body responsible for

Answer 14

Auditory sensory pathways.

Question 15

What is the lateral geniculate body responsible for

Answer 15

Visual sensory pathways

Question 16

What are the ventral anterior and ventral lateral nucleus responsible for

Answer 16

Pathways from the basal ganglia and cerebellum and primary motor cortex and sensory cortex influencing movement

Question 17

What is the ventral posterior nucleus responsible for

Answer 17

Relates sensory information to and from primary sensory cortex

Question 18

What is the function of the internal capsule

Answer 18

Only way in and out of the cortex!

Question 19

What are the divisions of the internal capsule

Answer 19

Anterior limb, genu, posterior limb, retrolenticular, sublenticular.

Question 20

What part of the internal capsule passes visual fibres

Answer 20

The retrolenticular

Question 21

What part of the internal capsule passes auditory fibres

Answer 21

The sublenticular

Question 22

What fibres pass through the genu

Answer 22

Motor for face- corticobulbar fibres

Question 23

What fibres pass through the anterior limb

Answer 23

Basal ganglia tracts

Question 24

What fibres pass through the posterior limb

Answer 24

Corticospinal tract, some visual, auditory and sensory pathways from the thalamus