Hcs156 Cerebral Hemispheres

Front 1

What does the surface of the cerebral hemispheres look like?

Back 1

Highly folded to give a large surface area

Front 2

What separates each area?

Back 2

Clefts separating each area = sulci

Raised areas between sulci = gyri

Front 3

Do the hemispheres contain white or grey matter? (3 points)

Back 3

1. Consists of a rim of grey matter (cortex) about 3-4mm thick

2. Central core of white matter

3. White matter contains discrete areas of grey matter

Front 4

What does the cerebral cortex consist of?

Back 4

Neuronal cell bodies, dendrites and synapses

Front 5

What does white matter consist of?

Back 5

Axons bundled together as tracts (pathways) running in 3 directions

Front 6

What are the 3 types of axons?

Back 6

1. Association axons

2. Commisural axons

3. Projection axons

Front 7

What is the function of association axons?

Back 7

Connect different areas in same hemisphere

Front 8

What is the function of commisural axons?

Back 8

Link right and left hemispheres

Front 9

What is the function of projection axons?

Back 9

Connect cortex with other areas of CNS or other areas of CNS to cortex to form motor and sensory tracts respectively

Front 10

How many types of sensation does each primary sensory area receive?

Back 10

One type

Front 11

Where do auditory stimuli project?

Back 11

To the auditory cortex in the temporal lobe

Front 12

Where do visual stimuli project?

Back 12

To the visual cortex in occipital lobe

Front 13

Where do somatosensory stimuli project?

Back 13

Project to somatosensory cortex in parietal lobe

Front 14

What is the function of the primary motor cortex?

Back 14

Controls movement of individual muscles or muscle groups

Front 15

How are the primary motor and somatosensory cortices arranged?

Back 15

Somatotopically - the body is represented in the correct anatomical order but the area of cortex devorted to each area is proportional to its importance in motor or sensory function

Front 16

What are the consequences of damage/disease of the sensory cortex?

Back 16

Loss of sensation (anaesthesia) from corresponding part of body

Front 17

How is the primary auditory cortex arranged?

Back 17

Tonotopically according to the frequency of sound input

Front 18

How is the visual cortex arranged?

Back 18

Complex with some areas responding to movement in different planes

Front 19

What are the consequences of damage/disease of the motor cortex?

Back 19

1. Spastic paralysis of contralateral muscles controlled by the area of the cortex affected

2. Hyperreflexia of the muscles affected (involuntary nervous system overreacts to stimuli)

Front 20

What do the areas of cortex outside the primary areas do? (3 points)

Back 20

1. Apart from two areas dedicated to language processing, rest of cortex is designated as association cortex

2. Secondary association areas are adjacent to the primary areas and integrate signals received in the primary areas and are unimodial (one type of sensation)

3. Tertiary association areas lie between the secondary areas and integrate signals of different modalities

Front 21

What is the role of the prefrontal association cortex? What is the clinical relevance?

Back 21

1. Mood and personality

2. Brain disease/damage does not respect anatomical or functional boundaries. Damage producing symptoms within speech may also affect other aspects of brain function too - allow for this in treatment planning and delivary

Front 22

What are the 4 effects of frontal association damage?

Back 22

1. Short attention span

2. Unaware of turn taking, pursue own agenda and ignore questions

3. Aggressive

4. Sensory neglect of their interpersonal space on opposite side of damage if it is localised

Front 23

What are 4 other possible effects of frontal association damage?

Back 23

1. Inattention to personal hygiene/toiletting behaviour

2. "Puerile jocularity" - laughing inappropriately

3. Unaware of/unconcern about seriousness of injuries/illness

4. Literal thinking - inability to understand complex ideas and metaphors

Front 24

Brocas and Wernickes area

Back 24

Lang processing (learn in greater detail elsewhere)

Front 25

What are the effects of disease/damage to the parietal association cortex?

Back 25

1. Effects skills and behaviour but dependent on which side of the brain due to laterality of function

Front 26

What are the effects of disease/damage to the right side of the parietal association cortex?

Back 26

Visuospatial function affected

eg. facial recognition, artistic ability, pattern recognition and 3D problems

Front 27

What are the effects of disease/damage to the left side of the paretal association cortex?

Back 27

Symbolic function affected

Eg. logic, language, mathematical ability

Front 28

What are the two hemispheres connected by?

Back 28

Corpus callosum - large bundle of transversely running axons

Front 29

What does damage/disease to posterior association cortex manifest as? (3 points)

Back 29

1. Agnosia

2. Apraxia

(Essentially associations cannot be made between stimuli and responses)

3. Specific effects on the posterior association

Front 30

What is agnosia? (2 points)

Back 30

Inability to interpret sensroy info although sensory systems are intact

eg. if placed a key in hand, client could tell you it is a cold metal object but could not identify it or tell you the function

Front 31

What is apraxia?

Back 31

Inability to make functional movements when motor systems are in tact

Front 32

What is ideatonal apraxia? (2 points)

Back 32

1. Actions occur automatically but not on command

eg. if you ask the person to brush hair away, they might not do it but they may brush it away spontaenously

2. Finds difficulty in sequencing complex movements

Front 33

What are 4 specific effects on the left parietal cortex?

Back 33

1. Sensory inattention to right side of environment

2. Left-right confusion

3. Alexia (impairment of reading)

4. Anomia (inability to name objects)

Front 34

What are 4 specific effects on the right parietal cortex? (3 points)

Back 34

1. Sensory inattention to left side of environment

2. Dressing apraxia - inability to dress properly, especially obvious on left side of the body

3. Constructional apraxia - inability to draw simple figures and shapes

Front 35

How can sensory inattention be shown/tested? (2 points)

Back 35

1. If asked to draw a clock - only number one side (eg. 6-12 if have right side neglect)

2. If asked to bisect a line - will draw a division halfway across the half of the line they perceive