Cerebral hemispheres - physiology Flashcards
Where is the precentral gyrus
Lateral to central sulcus on the frontal lobe side
Where is the post central gyrus
Lateral to the central sulcus on the parietal lobe side
Where is the cingulate gyrus
Lies on medial surface of the hemispheres above the corpus callosum and is formed by parts of frontal and parietal lobes
Cingulate gyrus is part of what system
Limbic system
Frontal lobe separated into 3 gyri
Superior/middle/inferior
Temporal lobe divided into 3 gyri
Superior/middle/inferior
Where is the transverse temporal gyrus
Buried within the lateral sulcus
Only seen when temporal lobe has been reflected down and some of frontal and parietal cut away
Parietal lobe divided into (2)
superior and inferior parietal LOBULE
Where is the insula
located deep within the lateral sulcus and is small region that is hidden under the temporal lobe and some of the frontal and parietal lobe
Sensory info goes to where first in the brain
thalamus
Cerebral cortex is divided into three functionally distinct areas:
sensory, motor, and association
Main sensory areas of the brain include (3)
primary auditory cortex, primary somatosensory cortex, and primary visual cortex
Which of these senses -sight, hearing, taste, touch, and smell - is the only one that is not routed to the cerebral cortex via the thalamus
Smell
-olfactory information passes through the olfactory bulb to the olfactory cortex, bypassing the thalamus
Which lobes of the brain contain sensory areas (3)
parietal, temporal and occipital lobe
Primary sensory areas receive sensory input from what
thalamus
Primary sensory areas send their info to…
whereas primary motor areas work a bit differently, info is passed from…
Primary sensory areas send their info to sensory association areas
whereas primary motor areas receive info from motor association areas
The cerebrum is derived from which primary brain vesicle
Prosencephalon
Which hemisphere is dominant if right handed
Left
What brodmann area is the primary motor cortex + what gyrus is the primary motor cortex
area 4
precentral gyrus
What brodmann areas are Broca’s area + what gyrus is it formed by
area 44, 45
inferior frontal gyrus
Broca’s area function
generation of articulate speech
What brodmann area is the premotor cortex
area 6
premotor cortex function
Cognitive functions of higher order - intellect, judgement, prediction, planning
what brodmann areas are the primary somatosensory cortex + what gyrus is the primary somatosensory cortex
Areas 3, 1, 2
postcentral gyrus
Function of superior parietal lobule
sensory association area
-interpretation of general sensory information and conscious awareness of contralateral half of body
Function of inferior parietal lobule
Interface between somatosensory cortex and visual and auditory association areas
In the dominant hemisphere, the inferior parietal lobule contributes to what
language functions
Superior and inferior parietal lobules often referred to as the what
GLOBAL ASSOCIATION AREAS
-because they provide a network between the primary cortexes
Parietal lobe lesion can result in what deficits (4)
Hemi-sensory neglect - reduced awareness of one side of visual field
Agnosia - unable to recognise things due to inability to interpret sensations
Acalculia - unable to do simple maths
Agraphia - loss/impaired writing
What brodmann areas are the primary auditory cortex
Areas 41, 42
What is heschl’s gyrus
aka transverse temporal gyrus
part of the primary auditory cortex
Auditory association area is present in both hemispheres but in the dominant hemisphere, what is it known as
Wernicke’s area
Wernicke’s area function
Responsible for the comprehension of speech (receptive), whereas Broca’s is for producing speech (expressive)
2 main sensory functions of temporal lobe
Hearing
smell
Inferior surface of temporal lobe plays what role
Receives fibres from olfactory tract allowing CONSCIOUS AWARENESS OF SMELL
Primary visual cortex is what brodmann area
Area 17
Primary visual cortex is on what surface of the occipital lobe
medial
Visual association cortex is what brodmann areas
Areas 18 and 19
Limbic lobe located on the medial surface of the cerebral hemispheres is formed by what 4 components + involved in what functions
Cingulate gyrus
Hippocampus
Amygdala
Parahippocampal gyrus
Memory + emotion
Broca’s area is in what lobe
Wernicke’s area is in what lobe
Frontal
Temporal
What happens in wernicke’s aphasia (when wernicke’s area damaged)
Don’t understand question asked (can’t comprehend anything) and don’t realise what they’re personally saying makes no sense (just meaningless words but thinks they’re speaking normal)
What happens in Broca’s aphasia (when Broca’s area damaged)
Can still understand words but struggle to put them together into articulate speech
Aware that what they’ve said doesn’t make sense so get frustrated
3 types of myelinated axon fibres
Commisural fibres
Association fibres
Projection fibres
Function of commissural fibres
Connect the 2 hemispheres and allow contralateral communication, e.g. corpus callosum made up of these fibres
Function of association fibres
Connect one part of a hemisphere to another part of the same hemisphere
Function of projection fibres
Run between the cerebral cortex and various subcortical centres (connect hemispheres with everything lower down)
Name some white matter areas that are made up of projection fibres (2)
Internal capsule
Corona radiata
After projection fibres pass through the internal capsule, they radiate out as the…
corona radiata to different lobes
What is the basal ganglia + what should it technically be called
collection of cell bodies inside the CNS located at the BASE OF THE HEMISPHERE
Basal nuclei because inside CNS
4 components of basal ganglia
Caudate nucleus
Putamen
Globus pallidus
Substantia nigra (functionally part of basal ganglia but not anatomically)
Globus pallidus + putamen =
lentiform nucleus
Input regions of the basal ganglia (2)
Output regions of the basal ganglia (2)
Input
- Caudate nucleus
- Putamen
Output
- globus pallidus
- substantia nigra
Basal ganglia function
Regulate initiation and termination of voluntary movements
