Cerebral hemispheres

Question 1

what are the general features of the cerebral hemispheres

Answer 1

sulcus - dip
gyrus - elevation
fissure - larger dip

grey matter on surface
white matter inside
lateral ventricle in the cavity of each hemisphere

Question 2

what is the name of the fissure that runs down the centre of the cerebrum from front to back

Answer 2

median longitudinal fissure

Question 3

what connects the right and left cerebral hemispheres

Answer 3

the corpus callosum - contains commissural fibres

Question 4

what is the name of the sulcus that runs across the top of the cerebrum left to right and what lies on either side

Answer 4

central sulcus

in front - precentral gyrus

behind - post central gyrus

Question 5

what does the central sulcus separate

Answer 5

parietal lobe from the frontal lobe

Question 6

what separates the parietal and occipital lobes

Answer 6

parieto-occipital sulcus

Question 7

what does the cingulate sulcus separate

Answer 7

parietal and frontal lobes from the cingulate gyrus

Question 8

what does the lateral sulcus (sylvan fissure) separate

Answer 8

parietal and frontal lobes above from temporal lobe below

Question 9

what is the posterior part of the cerebrum for

Answer 9

sensory

parietal - somatosensory
occipital - vision
temporal - hearing and smell

Question 10

what is the anterior part of the cerebrum for

Answer 10

motor

frontal - motor function and intellect

Question 11

what are the medial portions of the brain for

Answer 11

limbic system - storage and retrieval of processed information

Question 12

within the frontal lobe - what are three important areas

Answer 12

area 4 - precentral gyrus

area 44,45 - inferior frontal gyrus

prefrontal cortex

Question 13

what happens in area 4 of the frontal lobe

Answer 13

precentral gyrus = PRIMARY MOTOR CORTEX

somototopic representation of contralateral half of the body

Question 14

what happens in areas 44,45 of the frontal lobe

Answer 14

inferior frontal gyrus = BROCAS AREA

motor speech

Question 15

what happens in the prefrontal cortex

Answer 15

cognitive functions of higher order intellect

judgement

prediction

planning

Question 16

within the parietal lobe - what are 3 important areas

Answer 16

areas 1,2,3 - post central gyrus

superior parietal lobule

inferior parietal lobule

Question 17

what happens in areas 1,2,3 of the parietal lobe

Answer 17

post-central gyrus = PRIMARY SENSORY CORTEX

recieves general sensations from contralateral half of body

Question 18

what happens in the superior parietal lobule

Answer 18

interpretation of general sensory info and conscious awareness of contralateral half of body

Question 19

what happens in the inferior parietal lobule

Answer 19

interface between somatosensory cortex and visual and auditory association areas

in dominant hemisphere = contributes to language functions

Question 20

what can occur if there is a lesion in the parietal lobe

Answer 20

hemisensory neglect
right-left agnosia
acalculia
agraphia

Question 21

what is hemisensory neglect

Answer 21

the inability of a person to process and perceive stimuli on one side of the body or environment, where that inability is not due to a lack of sensation

Question 22

what is right-left agnosia

Answer 22

inability to differentiate right and left

Question 23

what is acalculia

Answer 23

difficulty perfoming simple mathematical tasks - different from dyscalculia as it is neurologically acquired later in life e.g. from stroke

Question 24

what is agraphia

Answer 24

loss of the ability to communicate through writing

Question 25

within the temporal lobe - what are 3 important areas

Answer 25

areas 41,42 - superior temporal gyrus auditory association areas inferior surface

Question 26

what happens in areas 41,42 of the temporal lobe

Answer 26

superior temporal gyrus = PRIMARY AUDITORY CORTEX

Question 27

what happens in the auditory association areas of the temporal lobe

Answer 27

WERNICKES AREA - understanding spoke word

Question 28

what happen in the inferior surface of the temporal lobe

Answer 28

conscious appreciation of smell

Question 29

within the occipital lobe - what are 2 important areas

Answer 29

area 17 - either side of the calcarine sulcus areas 18,19 - visual association cortex

Question 30

what happens in area 17 of the occipital lobe

Answer 30

PRIMARY VISUAL CORTEX

Question 31

what happens in areas 18,19 of the occipital lobe

Answer 31

interpretation of visual images

Question 32

what does the limbic lobe include

Answer 32

cingulate gyrus, hippocampus, parahippocampal gyrus, amygdala

Question 33

what is the role of the limbic lobe

Answer 33

memory and emotional aspects of behaviour

Question 34

what are the two language areas of the brain

Answer 34

brocas - motor speech wernickes - recognition of spoken word damage in either area can cause aphasia

Question 35

what occurs in brocas aphasia

Answer 35

damage to frontal lobe can understand speech misses small words out e.g. "walk dog" instead of "walk THE dog" aware of difficulties in speech weakness/paralysis of one side of the body

Question 36

what occurs in wernickes aphasia

Answer 36

damage to temporal lobe can't understand speech fluent speech with new meaningless words e.g. "you know what poodle and that I want to get and round him like you want before" unaware of mistakes no paralysis

Question 37

what are the three types of white matter myelinated axon fibres and what do they do

Answer 37

commissural - connect hemispheres association - connect one part of cortex with another projection - connect cerebrum with subcortical centres e.g. spinal cord

Question 38

what is the internal capsule

Answer 38

narrow area projection fibres passing to and from cerebral cortex derives blood supply fro middle cerebral artery - frequently affected in stroke

Question 39

what are basal ganglia

Answer 39

collection of neuronal cell bodies (grey matter) buried deep within the white matter of each hemisphere

Question 40

what are the 3 main basal ganglia

Answer 40

caudate putamen globus pallidus (subthalamic nucleii)

Question 41

what is functionally part of the basal ganglia but not anatomically

Answer 41

substantia nigra - found in the midbrain

Question 42

what is the major function of the basal ganglia

Answer 42

initiation and termination of movements

Question 43

what are common pathologies o the basal ganglia

Answer 43

parkinsons, athetosis, chorea

Question 44

what are the input regions of the basal ganglia

Answer 44

caudate | putamen

Question 45

what are the output regions of the basal ganglia

Answer 45

globus pallidus substantia nigra globus plaids then projects to thalamus - sends fibres to primary motor cortex

Question 46

SUMMARY: general structure of the cerebral hemispheres

Answer 46

outer grey matter inner white matter deep in white matter - basal ganglia (grey matter)

Question 47

SUMMARY: what separates and connects the two lobes respectively

Answer 47

median longitudinal fissure corpus callosum

Question 48

SUMMARY: what are the 2 main sulcii

Answer 48

central lateral parieto-occipital

Question 49

SUMMARY: what is the role of the frontal lobe

Answer 49

thinking, motor cortex, brokers speech area

Question 50

SUMMARY: what is the role of the parietal lobe

Answer 50

sensory

Question 51

SUMMARY: what is the role of the temporal lobe

Answer 51

auditory, wernickes areas (language), smell

Question 52

SUMMARY: what are the three fibres in the white matter

Answer 52

association commissural projection

Question 53

SUMMARY: what do the basal ganglia do

Answer 53

control movement by connecting to motor cortex (starting and stopping of movements)