Cerebral Hemispheres

Question 1

What are the general features of the cerebral hemisphere?

Answer 1

Sulcus (dip), gyrus (elevation), fissure (deeper dip), grey matter on surface, white matter inside , basal ganglion in white matter, lateral ventricle is the cavity in each hemisphere

Question 2

What is the main fissure separating each hemisphere?

Answer 2

Median longitudinal fissure

Question 3

What is the corpus callosum?

Answer 3

Large white matter tract that connects the 2 hemispheres of the brain

Question 4

What separates the pre and post-central gyrus?

Answer 4

Central sulcus
Also separates the frontal and parietal lobe

Question 5

What separates the frontal and temporal lobes?

Answer 5

Lateral sulcus

Question 6

What separates the parietal and occipital lobes?

Answer 6

Parieto-occipital sulcus

Question 7

What is separated by the cingulate sulcus?

Answer 7

Parietal and frontal lobes
Is on medial surface of the hemisphere

Question 8

What is the frontal lobe split into?

Answer 8

Split into superior, middle and inferior gyrus

Question 9

What is the temporal lobe split into?

Answer 9

Superior, middle and inferior temporal gyri

Question 10

What is the parietal lobe split into?

Answer 10

Superior and inferior parietal lobule

Question 11

Describe the insula of the brain

Answer 11

Found in transverse temporal gyri - Heschl’s convolutions

Question 12

Which part of the brain is motor and which part is sensory?

Answer 12

Posterior part after central sulcus is sensory and anterior part is motor
There are primary sensory areas ad associated areas

Question 13

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

Answer 13

Storage and retrieval of processed information
Limbic system

Question 14

Is the frontal lobe motor or sensory?

Answer 14

Motor

Question 15

Describe the primary motor cortex in the frontal lobe

Answer 15

Area 4 - pre-central gyrus
Somatotopic representation of contralateral half of body - motor homunculus

Question 16

What area is the inferior frontal gyrus?

Answer 16

Broca’s area of motor speech
Area 44 and 45

Question 17

What is the function of the prefrontal cortex in the frontal lobe?

Answer 17

Cognitive functions of higher order intellect, judgement, prediction and planning

Question 18

What type of neurons is the parietal lobe?

Answer 18

Somatosensory

Question 19

What is the primary sensory area of the parietal lobe?

Answer 19

Post central gyrus - Area 3,1,2
Receives general sensations from contralateral half of body
Somatotopic representation - sensory homunculus

Question 20

What is the superior parietal lobule?

Answer 20

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

Question 21

What is the inferior parietal lobule?

Answer 21

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

Question 22

What happens if there is parietal lobe lesion?

Answer 22

Hemisphere neglect
Right left agnosia
Acalculia - signs of dementia
Agraphia - inability to spell and communicate by writing

Question 23

What are the main functions of the temporal lobe?

Answer 23

Hearing and smell

Question 24

What is the superior temporal gyrus?

Answer 24

Primary auditory cortex
Areas 41 and 42

Question 25

What are the auditory association areas of the temporal lobe?

Answer 25

Posterior to 41 and 42 In dominant hemisphere is called the Wernicke's area Crucial for understanding for spoken word and has connections with other language areas

Question 26

What is the main function of the occipital lobe?

Answer 26

Vision

Question 27

What are the main areas of the occipital lobe?

Answer 27

On medial surface - on either side of calcarine sulcus is the primary visual cortex (area 17) Rest is visual association cortex (areas 18 and 19) and concerned with interpretation of visual images

Question 28

Where is the limbic lobe?

Answer 28

Medial surface of cerebral hemisphere has areas which together form functional limbic lobe

Question 29

What is the function of the functional limbic lobe?

Answer 29

Memory and emotional aspects of behaviour

Question 30

What does the limbic lobe include?

Answer 30

Cingulate gyrus, the hippocampus, parahippocampal gyrus, and amygdala

Question 31

What are the language areas of the brain?

Answer 31

Broca's area is the motor speech area Wernicke's area is auditory association in dominant hemisphere

Question 32

What is aphasia?

Answer 32

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

Question 33

What is Broca's aphasia?

Answer 33

Understands speech but misses small works, is aware of difficulties Damage to frontal lobe Weakness/paralysis of one side of body

Question 34

What is Wernicke's aphasia?

Answer 34

Fluent speech, with new meaningless words as cant understand speech and doesn't know of mistakes Damage to temporal lobe No paralysis

Question 35

What are the 3 types of myelinated axon fibres bundled into tracts?

Answer 35

Commissural fibres Association fibres Projection fibres

Question 36

What is the function of commissural fibres?

Answer 36

Connect corresponding areas of two hemispheres

Question 37

What is the function of the association fibres?

Answer 37

Connects of part of cortex with other and may be short or long Short connect primary and association areas Long connect lobes

Question 38

What is the function of projection fibres?

Answer 38

Run between the cerebral cortex and various subcortical centres Pass through corona radiata and internal capsule

Question 39

Describe a 3D cerebral tractography

Answer 39

3D modelling technique that maps functional white matter tracts using data collected using MRI Based on symmetry of brain water diffusion

Question 40

Describe the internal capsule

Answer 40

Made up of projection fibres passing to and from the cerebral cortex Narrow area between thalamus and caudate nucleus medially and lentiform nucleus laterally

Question 41

What is the blood supply of the internal capsule?

Answer 41

Middle cerebral artery and is frequently affected by strokes

Question 42

Describe the basal ganglia

Answer 42

Subcortical nuclei (collection of neuronal cell bodies in grey matter) deep in each cerebral hemisphere Made up of caudate nucleus, putamen and globus pallidus Also a part is the substantia nigra

Question 43

What are the individual basal ganglia?

Answer 43

Caudate (has tail) Putamen (hard shell) Globus pallidus (pale globe) Substantia nigra (lies in midbrain) Subthalamic nuclei

Question 44

What makes up the lentiform nucleus?

Answer 44

Putamen and globus pallidus

Question 45

Where is the caudate nucleus?

Answer 45

Starts as large head medial to internal capsule, a body and slender curving tail which follows curve of the lateral ventricle

Question 46

What are the input regions of basal ganglia?

Answer 46

Caudate nucleus and putamen Receive input from motor cortex, premotor cortex and thalamus

Question 47

What are the output regions of basal ganglia?

Answer 47

Input region connected to output regions Globus pallidus and substantia nigra

Question 48

Where does the globus pallidus project to?

Answer 48

Primarily to the thalamus which sends fibres to motor area of cortex

Question 49

What is the main function of the basal ganglia?

Answer 49

Help regulate initiation and termination of movements They play a role in controlling the motor system - extrapyramidal system

Question 50

What pathology can be associated with basal ganglia?

Answer 50

Parkinson's, chorea and athetosis