Cerebral hemispheres Flashcards
What is the difference between a sulcus and a fissure
Fissure is deeper than a sulcus
What are elevations in the cerebral hemispheres called in the cerebrum and the cerebellum Called?
Cerebrum: gyrus Cerebellum: Folia
What does the longitudinal fissure divide?
The two cerebral hemispheres
what does the central sulcus divide?
The frontal and parietal lobe
What does the lateral sulcus/ sylvian fissure
Separates the temporal lobe from the parietal/frontal
What does the calcirine fissure divide?
The two occipital lobes
What is the insula?
-Small section of the cerebral cortex located in the lateral sulcus -Separates the Frontal and parietal lobes from the temporal lobe
What is the principle on which cortical mapping is based on?
Based on the idea that different parts of the brain have different functions as they are histologically different
What are the different parts of the cerebrum responsible for?
Anterior Cerebral hemisphere: Motor function of any kind (Frontal)
Posterior Cerebral hemisphere: Sensory function –
- Temporal: smell and hearing
- Parietal: somatosensory (pain, temperature…) -
- Occipital: Vision
Lateral cerebral hemisphere: Limbic function (emotion)
What is the difference between a primary area and an associated area?
-Receptors initially send an impulse( based on a detection of change) to the primary areas -Primary areas send info to the adjacent associated areas -Associated areas then process the information and make you aware of what you are feeling
Which area are found in the frontal lobe?
Area 4: primary Motor cortex
Area 44,45: Broca’s area
Area 6 is the pre-motor zone
Area 4: primary motor cortex
Area 44, 45: Broca’s area
Area 6: Pre-motor zone
Cognition, intellect also controlled in pre-frontal cortex
Area 3,1,2: primary sensory cortex
Receives sensory information from contralateral side of body
Superior parietal cortex:
Association area
Interpretation of general sensory information and consciousness
Inferior parietal cortex:
Also known as globule
Interface between primary sensory cortex and the associated cortexes of vision, nose and smell
Only on dominant side contributes to speech
Areas 41,42
Primary Auditory cortex
In superior temporal gyrus
Wernicke’s area :
Posterior to primary auditory cortex
Sensory control of speech- crucial for understanding speech
Inferior tract:
Receives sensory information about smell
Area 17
Primary vision cortex
On either side of calcimine sulcus
Association area is rest of it
Limbic lobe
Hippocampus
Cingulate gyrus
Parhippocampal gyrus
Amygdala
What happens when Wernicke’s area is damaged
Cannot make sentences
Cannot understand that what is being said does not make sense
Cannot understand what is being said
What happens when Broca’s area is affected
Can still make sense of everything
Cannot formulate speech
Which speech area is most likely to be affected by a stroke?
Broca’s as it is found in the frontal cortex
What do commisural fibres do?
connect two hemispheres
What do projection fibres do?
connect the cerebrum with everything (subcortical centres)
-The neurone pass up to the cerebrum from here through the Corona Radiator
what do association fibres do?
connect different part of the hemispheres
- short: from primary to associated
- Long: e.g. from visual cortex to temporal
What is the internal capsule?
Collection of white matter which transmits all sensory and Motor information
why is the internal capsule usually implicated in strokes?
Its main blood supply is the middle meningeal artery
What are the basal ganglia
Collection of neuronal cell bodies in the CNS- should be called basal nuclei
Grey matter
What is the function of the basal ganglia
- The caudate nucleus and the putamen are input zones from the pre-motor cortex, the thalamus and the motor cortex
- The output regions are the globus pallidus and the substantial nigra
- The output regions then project back to the thalamus
- They basically are involved in co-ordination of initiation and termination of movements
What are the basal ganglia also known as?
The extrapyrimidal system as they are involved in the motor system
What makes up the lentiform nucleus?
The globus pallidus and the putamen
What does somatotopic mean?
Somatotopic: neurones from a specific area of the precentral gyrus will send impulses to specific part of the body
Lot more neurones to the hand- to allow movement- compared to the rest of the arm as the movements of the hand are a lot more fine tuned.
Depending on how much movement a muscle can perform it will get more or less room on the precentral gyrus
