Cortical organisation and function Flashcards
Where is the primary motor cortex
In front of the central sulcus. Broadman’s area 4
Where is the primary somatosensory cortex
Behind the central sulcus. Broadman’s areas 1,2,3
What are the functions of the Parietal lobe
Sensation: touch pain
Sensory aspects of language
Spatial orientation and self perception
What are the functions of the Frontal lobe
Regulating and initiating motor function
Language
Cognitive functions (executive function eg planning)
Attention
Memory
Eg someone with frontal lobe defects could have major changes in personality
What are the functions of the occipital lobe
Processing visual information
What are the functions of the temporal lobe
Processing auditory information
Emotions
Memories
what does the limbic lobe (limbic system include)
Amygdala, hippocampus, mamillary body, and cingulate gyrus
What are the functions of the limbic lobe
Learning
Memory
Emotion
Motivation
Reward
Where is the insular cortex
behind the lateral fissure
What is the function of the insular cortex
Visceral sensations (sensations from inside the body)
Autonomic control
Interoception
Auditory processing
visual-vestibular integration (world not behaving the way you think its behaving) eg diziness
(eg sense of hunger and thirst etc)
what is the grey matter made up of
Neuronal cell bodies and glial cells (around 85 billion of each)
What does the white matter contain
Myelinated neuronal axons arranged in tracts
What are white matter tracts
connect cortical areas within the same hemisphere and between hemispheres
What are association fibres
connect areas within the same hemisphere
What are Commissural fibres
Connect homologous structures in the left and right hemispheres. Also present in the spinal cord
What are projection fibres?
Connect cortex with lower brain structures (thalamus, brain stem, spinal cord).
Types of fibres
If asked what are the type of fibres then answer is association fibre if asked what is the name of the fibre then give name of tract eg superior longitudinal fasiculus
What are the different types of association fibres
Long fibres and short fibres
name the different Association fibre tracts
Superior longitudinal fibres: connects frontal and occipital lobes
Arcuate fasciculus: connects frontal and temporal lobes (arcuate means arching)
Inferior longitudinal Fasciculus connects temporal and occipital lobes
Uncinate faciculus connects anterior frontal and temporal lobes
this is why different areas may have same functions as they are connected by fibres
What are the types of Commissural fibres
Corpus Callosum
Anterior commissure
In which condition is the corpus callosum disconnected
Intractable epilepsy (untreatable) (corpus callosotomy)
To stop the spreading of seziures from one hemisphere to the other hemisphere. this is sometimes known as a hemispherectomy
What are afferent projection fibres
Going towards the cortex
What are efferent projection fibres
Going away from the cortex
What is the corona radiata
A specific region of projection fibres deep to the cortex (on their way down from the cortex going to the lower structures).
where do the projection fibres converger
Converge through internal capsule between thalamus and basal ganglia
what area is the rectangle
internal capsule. Inbetween the thalamus and basal ganglia
What are the outlines areas
internal capsule
What does the basal ganglia do
Coordinates movement
What are association cortices
they surrounded the primary cortices
function less predictable
not organised topographically
left right symmetry week or ansent
What are primary cortices
Function predictable
Organised topographically
Symmetry between left and right
What are the areas denoted by the red arrows
What are the primary and supplementary motor areas of the frontal lobe
Primary :
controls fine, discrete, precise voluntary movements.
Provides descending signals to execute movements.
Supplementary
Involved in planning complex movements (e.g. internally cued (eg sppech))
Premotor area
involved in planning movements (e.g. externally cued (reacting to something you have seen in the outside world like reaching for an object and picking it up)
(less predictable but more complex-if you stimulate the supplementary and premotor area, complex sequences of movements can occur, if you stimulate the primary motor cortex a few muscles will twitch