Cerebral Cortex

Question 1

What is the cerebral cortex responsible for?

Answer 1

the qualities that distinguish humans from other animals

Question 2

How does the cerebral cortex fit within the volume of the brain?

Answer 2

it has many folds i.e. gyri and sulci

Question 3

What is the primary excitatory cell type of the cerebral cortex?

Answer 3

pyramidal neurons

Question 4

What is the neurotransmitter of pyramidal neurons?

Answer 4

glutamate

Question 5

Where do small and medium pyramidal cells project to?

Answer 5

areas of the ipsilateral cortex

Question 6

Where do large and giant pyramidal cells project to?

Answer 6

ipsilateral and contralateral cortex subcortical areas, brainstem and spinal cord

Question 7

What is the neurotransmitter for non-pyramidal neurons?

Answer 7

GABA

Question 8

What does layer III of the cerebral cortex contain?

Answer 8

medium pyramidal cells whose axons project to the ipsilateral cortex

Question 9

What is layer IV of the cerebral cortex?

Answer 9

the major input layer that receives input from the thalamus

Question 10

What is layer V of the cerebral cortex?

Answer 10

the major output layer that contains medium, large and giant pyramidal cells

Question 11

What does each vertical column contain?

Answer 11

about 200 neurons that form functional units

Question 12

How many Brodmann areas are there?

Answer 12

52

Question 13

What do short association fibres do?

Answer 13

connect adjacent gyri within one hemisphere

Question 14

What do long association fibres do?

Answer 14

connect different cortical regions within one hemisphere e.g. arcuate fasciculus

Question 15

What does the corpus callosum do?

Answer 15

connect homologous regions of the two hemispheres

Question 16

What do projection fibres do?

Answer 16

connect the cerebral cortex with the subcortical brainstem and spinal cord regions

Question 17

What are corticopetal fibres?

Answer 17

input fibres that run towards the cerebral cortex

Question 18

What are corticofugal fibres?

Answer 18

output fibres that exit the cerebral cortex

Question 19

When may aminergic axons be altered?

Answer 19

in psychiatric disorders

Question 20

Where is the primary visual cortex (area 17)?

Answer 20

on both sides of the calcarine sulcus, on the medial aspect of the occipital lobe

Question 21

Where does the primary visual cortex receive visual information from?

Answer 21

the contralateral visual field

Question 22

What does stimulation of the primary visual cortex cause?

Answer 22

crude sensations of bright flashes of light

Question 23

What would damage to the primary visual cortex result in?

Answer 23

loss of vision in the contralateral visual field

Question 24

What are the occipital visual areas (18 and 19) responsible for?

Answer 24

the “what” stream of visual processing

Question 25

What do the occipital visual areas do?

Answer 25

interpret the visual impulses that reach the primary visual cortex (area 17)

Question 26

What is agnosia?

Answer 26

the inability to recognise things even though one sees them

Question 27

What does stimulation of the occipital visual areas cause?

Answer 27

hallucination of formed images

Question 28

What does damage to the occipital visual areas cause?

Answer 28

visual agnosia

Question 29

Where is the primary auditory cortex?

Answer 29

on the superior part of the temporal lobe, in areas 41 and 42 called Heschl’s gyri

Question 30

What is the function of the primary auditory cortex?

Answer 30

hearing

Question 31

What does stimulation of the primary auditory cortex cause?

Answer 31

tinnitus

Question 32

What does damage to the primary auditory cortex cause?

Answer 32

slight hearing loss

Question 33

Where is the auditory association area (Wernicke's speech area)?

Answer 33

beind the primary auditory cortex in the dominant hemisphere (left superior temporal lobe) area 22

Question 34

What happens if the auditory association (Wernicke's) area is damaged?

Answer 34

word deafness or auditory aphasia i.e. the patient can hear what is being said without knowing what it means

Question 35

Where is the primary somatosensory cortex?

Answer 35

on the postcentral gyrus of the parietal lobe (areas 1, 2 and 3)

Question 36

What does the superior parietal lobe (areas 5 and 7) have reciprocal connexions with?

Answer 36

the primary somatosensory cortex and the dorsal tier of lateral thalamic nuclei

Question 37

What is the superior parietal lobe concerned with?

Answer 37

discriminative aspects of sensation, such as the qualities of shape, roughness, size and texture and also in remembering the positions of objects in space

Question 38

What could a lesion in the superior parietal lobe cause?

Answer 38

- inability to identify familiar objects manually (tactile agnosia) - unawareness of the side of the body opposite to the lesion

Question 39

What does damage to the inferior parietal lobe (areas 39 and 40) cause?

Answer 39

word-blindness (alexia) and inability to copy (agraphia)

Question 40

What is sensory aphasia?

Answer 40

the inability to understand written and spoken language

Question 41

Where is the primary motor cortex and what is it responsible for?

Answer 41

in the pre central gyrus (area 4) of the frontal lobe concerned with initiating voluntary movements

Question 42

What does stimulation of the primary motor cortex cause?

Answer 42

discrete and isolated movement limited to a single joint or muscle

Question 43

What does damage of the primary motor cortex lead to?

Answer 43

- upper motor neuron lesion - contralateral side of the body being affected - initial hypotonia, hyporeflexia or flaccid paralysis followed by chronic hyperreflexia and spasticity - Babinski sign (extension of the big toe)

Question 44

What is the premotor area?

Answer 44

area 6 associated with area 4 to help with voluntary movements

Question 45

Where is Broca's area (area 44 and 45)?

Answer 45

on the inferior frontal gyrus in the triangular and opercula regions

Question 46

What can damage to Broca's area cause?

Answer 46

the individual being unable to talk, even though the vocal muscles are not paralysed; the patient knows what they want to say but all that comes out is garbled sound, or one word repeated over and over again

Question 47

What is the frontal eyefield (area 8) concerned with?

Answer 47

the voluntary conjugate movements of both eyes

Question 48

What does stimulation of the frontal eyefield cause?

Answer 48

deviation of both eyes to the contralateral side

Question 49

What does damage of the frontal eyefield cause?

Answer 49

deviation of both eyes to the ipsilateral side

Question 50

What are functions of the prefrontal cortex?

Answer 50

- motor planning - planning for the future - language production - holding memory

Question 51

What can damage to the prefrontal cortex lead to?

Answer 51

- changes in mood, behaviour and personality - individual neglecting their appearance, laughs or cries inappropriately and demonstrates no appreciation of social norms

Question 52

What is the dominant hemisphere dominant for?

Answer 52

language

Question 53

What is the non-dominant hemisphere responsible for?

Answer 53

the appreciation of spatial dimensions, totality of a scene (including recognition of faces) and nonverbal symbolism

Question 54

What does the right temporal lobe do?

Answer 54

store tone memories

Question 55

What can damage to the parietal lobe lead to?

Answer 55

hemi-neglect syndrome; reduced awareness of stimuli on one side of space, even though there may be no sensory loss