Lecture 14: Cerebral Cortex

Question 1

job of the cerebral cortex

Answer 1

• interpreting sensory information
• perception of sensory information
• active in conscious decisions
• planning, execution, accuracy

Question 2

Most knowledge of Cortex and Cerebellum activity is due to _______.

Answer 2

study of brain injured individuals

Question 3

The cerebral cortex demonstrates a characteristic multilayer structure seen in a vertical section. It contains two types of cells which are:____.

Answer 3

pyramidal and stellate

Question 4

The Molecular layer (I) contains:

Answer 4

axons and dendrites

Question 5

The External granular layer (II) contains:

Answer 5

small pyramidal and stellate cells

Question 6

The External Pyramidal layer (III) contains:

Answer 6

mainly pyramidal cells

Question 7

The Internal granular Layer (IV) contains:

Answer 7

stellate and pyramidal cells

Question 8

The Granular Layer (V) contains:

Answer 8

large pyramidal cells

Question 9

The Multiform Layer (VI) contains:

Answer 9

many different neurons that leave the cortex

Question 10

Most input to the cortex comes from ____.

Answer 10

the thalamus

Question 11

Thalamus acts as a ____.

Answer 11

relay station.

Question 12

The thalamus processes information from:

Answer 12

the peripheral afferents, the cerebellum, and the basal ganglia

Question 13

Thalamic inputs make synaptic connections in which later?

Answer 13

IV- Internal Granular Layer [stellate cells]

Stellate cells then synapse with pyramidal cells
Pyramidal cells receive sensory information from the thalamus and cortex

Question 14

_______ divided the cerebral cortex into over 50 Areas.

Answer 14

Brodmann

Question 15

Areas ___ and ____ are of particular importance for control of movements

Answer 15

4 and 6

Question 16

Area ___ is the Primary Motor Area

Answer 16

4

Question 17

Area 4 contains what type of cells.

Answer 17

giant output cells, particularly in zone with projections to leg muscles

Question 18

what kind of map is contained in Area 4?

Answer 18

contains a motor map of the body (somatic organization)

Question 19

Area 4: Electrical stimulation of certain areas induces___________.

Answer 19

local muscle contractions

Question 20

Area 4: Active during the execution of _____.

Answer 20

voluntary movements

Question 21

Damage to Area 4 can cause:

Answer 21

paralysis and spasticity (upper motor neuron syndrome)

Question 22

Area ___ is the Premotor Area

Answer 22

6

Question 23

Complex movements originate in ______

Answer 23

Area 6

Question 24

the _____ is responsible for constructing movements from external cues (example visual cues)

Answer 24

Premotor Cortex

Question 25

the ____ is responsible for constructing movements from internal motor memory and using bimanual coordination, although recent research has challenged the bimanual coordination.

Answer 25

supplementary motor area

Question 26

MA: primary motor area responsible for

Answer 26

motor execution

Question 27

SMA: supplementary motor area responsible for

Answer 27

motor preparation (motor memory)

Question 28

PMA: premotor area responsible for

Answer 28

interpreting clues or stimuli

Question 29

parietal areas are responsible for

Answer 29

proprioceptive information, speech, and verbal expression

Question 30

Inputs to the motor cortex from the spinal cord, the basal ganglia, and the cerebellum are mediated by

Answer 30

the ventrobasal nuclei of the thalamus.

Major projections from other cortical areas include those from the parietal cortex and from certain frontal areas.

Question 31

Outputs of the motor cortex include projections to

Answer 31

the basal ganglia, the cerebellum (via the pons), the red nucleus, the reticular formation, and the spinal cord.

Corticospinal tracts from the left and right hemispheres change sites at the level of the medulla (at the decussation)

Question 32

Convergence

Answer 32

stimulating different cortical cells may activate the same group of motor units and result in similar motions

Question 33

Divergence

Answer 33

stimulating one cortical cell can activate different groups of motor units and move different body parts

Question 34

The activity of any given cortical neuron affects a number of physical characteristics defining a movement and these effects depend on

Answer 34

the external loading conditions in which the movement proceeds

Question 35

Any physical characteristic of movement is likely reflected in _______

Answer 35

activation of patterns of distributed populations in cortical cells