Cerebral hemishperes - Grey matter (1st half)

Question 1

Identify the general features of the cerebral hemispheres on the diagram

Answer 1

Question 2

The elevations in the cerebrum are called Gyri

How is this different from the cerebellum?

Answer 2

In the cerebellum - the bumps are called ‘folia’ (not sure if right spelling)

Question 3

What are basal ganglia?

Answer 3

Collections of neuronal cell bodies within white matter

They are just CNS ‘Nuclei’

Question 4

What is this structure here?

Answer 4

Corpus Callosum

Thick band of white matter (nerve fibres) that anatomically divides but neurally connects the two hemispheres of the brain

Question 5

In this photo of the brain, what is the stuff covering the left hemisphere?

Answer 5

Covered in pia mater (the innermost meningeal layer) which is vascularised - hence all the blood vessels

Remember the CSF sits between the arachnoid and pia mater

Question 6

Identify the fissures in green and the lobes in blue

Answer 6

Question 7

What is this?

Answer 7

The Pre-central gyrus

The gyrus immediately anterior to the central sulcus

Primary motor cortex

Question 8

What is this?

Answer 8

Post central gyrus

Primary sensory cortex

Question 9

Identify the parietooccipital sulcus and central sulcus of the brain in the photo

Answer 9

Parietooccipital sulcus in red

Central sulcus in blue

Question 10

What gyrus is this arrow pointing to?

What is its associated sulcus?

Answer 10

Cingulate gyrus that runs around the Corpus callosum

Question 11

What is this area?

Which lobe is it?

Answer 11

The Hippocampus

This is the part of the Temporal lobe that faces medially and is more or less hidden away

Question 12

Identify the labels boy

Answer 12

Question 13

If you were to open the lateral sulcus up. You would see this.

What area of the brain is this?

Answer 13

The insula:

The transverse temporal gyri are not on the insular surface. You can see were they are on the brain on the diagram

Question 14

What is Cortical mapping?

Answer 14

Mapping of 52 areas across the brain, each of which has its own microscopic differences according to its function

These areas are called Brodmann areas

Question 15

Broadly speaking. The anterior half (frontal lobe) of the cerebrum is associated with _______ functions and the posterior half carries out _______ functions

Answer 15

Frontal lobe (anterior half of brain pretty much) = Motor functions

Posterior (all the others) = Sensory functions

Question 16

Complete the labels for the general function(s) of each lobe

Answer 16

Question 17

What is the function of the medial portions of the cerebral hemispheres?

Answer 17

Limbic system - storage and retrieval of processed information

Question 18

What is meant by primary sensory areas and association areas?

Answer 18

The primary sensory areas are the primary cortical regions of the five sensory systems in the brain. Except for the olfactory system.

So the information received from eg your fingers when you’re touching something goes to your primary sensory area for touch etc

Your association areas take look at the information from your PSA and look for patterns, so you can recognise/appreciate what you’re touching/seeing etc etc

Question 19

Is there association areas in the frontal lobe? (motor association areas?)

Answer 19

Yeah

They basically formulate the plan (pattern of motor signals) that will achieve a task

So:

• the very front of the frontal lobe will decide ‘im gonna pick up that pen’
• The bit anterior to the primary motor cortex/pre-central gyrus will make the plan for which nerves to fire and when - in order to pick up the pen
• The primary motor cortex will then carry out the instructions made

So thats the job of the motor association areas

Question 20

What is the primary motor cortex?

Which Brodmann area is it?

Answer 20

Area 4

Somatotopic representation of the contralateral half of the body

This means that all muscles in the other half of the body are represented (controlled) in the primary motor cortex gyrus

Question 21

What areas of the body require the most space on the primary motor cortex?

Answer 21

Those that carry out fine motor movements

This means the hands, face, tongue require more space than say the hip

Question 22

What is the pre-motor cortex?

Answer 22

Areas 6 & 8

This is the part which decides how (plans the neurons firing and when) for a motor task

Question 23

What is the Brocas area of speech?

What Brodmann areas?

Answer 23

Areas 44, 45

These are the areas associated with speech. They are located very close to the areas for hearing as well.

Question 24

What is the purpose of the pre-frontal cortex?

Answer 24

cognitive functions of higher-order - intellect, judgement, prediction, planning

Question 25

What is located in groups 3, 1, 2?

Answer 25

The primary sensory area (ie the post-central gyrus)

Receives general sensations from contralateral half of body. Somatotopic representation

Question 26

What are these areas and what do they do?

Answer 26

Superior & inferior parietal lobules

Superior:

• Interpretation of general sensory information (sensory association area) and conscious awareness of contralateral half of body

Inferior:

• Interface between somatosensory cortex and visual and auditory association areas. In dominant hemisphere, contributes to language functions.

Question 27

What is hemisensory neglect?

Answer 27

Presentation of a parietal lobe lesion

The patient has literally no awareness of one half of their body (contralateral side to lesion)

Patient given 3 pictures to draw and will do something like this…

Question 28

What are the signs of a parietal lobe lesion?

Answer 28

• Hemisensory neglect
• Right-left agnosia - inability to interpret sensations and hence to recognize things
• Acalculia - inability to calculate
• Agraphia - inability to write

Question 29

What part of the temporal lobe is associated with hearing?

Answer 29

Superior Temporal gyrus – Primary auditory cortex –

Areas 41,42

Question 30

Which part of the temporal lobe is associated with the comprehension of speech?

Answer 30

Wernicke’s area

This is the association area for hearing and lies just above areas 41, 42 (PAC)

It is only called ‘Wernicke’s area’ on the Dominant hemisphere - this area deals with language comprehension

Question 31

What area of the temporal lobe is associated with the conscious appreciation of smell?

Answer 31

Inferior surface – receives fibres from olfactory tract – conscious appreciation of smell.

Question 32

What area(s) of the brain is associated with vision

Answer 32

Primary visual cortex (area 17).

This is found on the medial surface of the occipital lobe, on either side of the calcarine sulcus

Areas 18, 19 are the visual association cortexes - concerned with the interpretation of visual images.

Question 33

Identify the labels

Answer 33

Question 34

Where is the limbic lobe of the brain and what does it do?

Answer 34

The medial surface of the cerebral hemisphere has areas which together form a functional limbic lobe involved in memory and emotional aspects of behaviour

It is made up of the:

• cingulate gyrus
• hippocampus (medial aspect of temporal lobe)
• parahippocampal gyrus
• amygdala ( subcortical grey matter close to temporal pole)

Question 35

Identify the parts of the limbic lobe on the diagram below

Answer 35

Question 36

Identify the language areas of the brain in the diagram

Answer 36

Question 37

What is aphasia?

Answer 37

problem with speech due to damage to one or more speech areas in brain

Question 38

What is the difference between Broca’s aphasia and Wernicke’s aphasia?

Answer 38

Broca’s:

• ‘Walk dog’
• Understands speech but Misses words
• Aware of speech difficulty
• Damage to frontal lobe - may have paralysis/weakness elsewhere

Wernicke’s aphasia:

• Fluent speech but new, random words (no sense)
• Not aware of aphasia
• Cant understand speech
• Damage to Temporal lobe
• ‘You know that smoodle pinkered & that I want to get him round & him like you want before’