The brain Flashcards
What are the four lobes of the cerebral hemispheres?
- Frontal
- Parietal
- Occipital
- Temporal
What is the function of the frontal lobe?
Mediates precise voluntary motor control, learned motor skills, planned movement, eye movement, expressive speech, personality, working memory, complex problem solving, emotions, judgement, socialisation, olfaction and drive
What is the function of the parietal lobe?
Affects sensory input, spatial discrimination, sensory representation and integration, and receptive speech
What is the function of the occipital lobe?
Affects visual input and processing
What is the function of the temporal lobe?
Mediates auditory input and auditory memory integration, spoken language (dominant side) and body language (non-dominant side)
How many ventricles are found in the brain?
4
What are the names of the ventricles?
- Two lateral ventricles
- Third ventricle
- Fourth ventricle
Where does CSF enter the subarachnoid space?
Through two lateral apertures (foramina of luschka) or a median aperture (foramen of Magendie)
Which brain regions are involved in attention?
Cortical ‘top down’ modulation:
- Dorsolateral prefrontal cortex
- Parietal cortex
- Limbic cortex
‘Bottom up’ modulation:
- The ascending reticular activating system (ARAS)
Which areas of the brain are associated with episodic memory?
- The medial temporal lobe (especially the hippocampus and diencephalon)
- Dorsolateral prefrontal cortex
What areas of the brain are involved in semantic memory?
Not dependent on limbic system
- Left hemisphere, in particular the anterior temporal cortex
- Parietal lobe, the angular gyrus
What areas of the brain are involved in implicit memory?
- Basal ganglia
- Cerebellum
What regions of the brain are supplied by the anterior cerebral artery?
the frontal, pre-frontal and supplementary motor cortex, as well as parts of the primary motor and primary sensory cortex.
What is the result of a left anterior cerebral artery infarct?
(rare because of the collateral circulation provided by the anterior communicating artery)
Right leg upper-motor neuron weakness due to damage to motor cortex and right leg cortical sensory loss due to damage to sensory cortex. Grasp reflex, frontal lobe behavioral abnormalities, and transcortical aphasia can also be seen if the prefrontal cortex and supplemental motor areas are involved
What is the result of a right anterior cerebral artery infarct?
(rare because of the collateral circulation provided by the anterior communicating artery)
Left leg upper-motor neuron weakness due to damage to motor cortex and left leg cortical type sensory loss due to damage to sensory cortex. Grasp reflex, frontal lobe behavioural abnormalities and left hemineglect can also be seen if the prefrontal cortex and non-dominant association cortex are involved.
What regions of the brain are supplied by the superficial divisions of the middle cerebral artery?
Left:
- broca’s area
- wernicke’s area
Left and right:
- motor cortex
- sensory cortex
What regions of the brain are supplied by the right lenticulostriate branches of the middle cerebral artery?
- stiatum
- globus pallidus
- internal capsule
Describe the deficits seen with an infarct in the Left MCA Superficial Division
Right face and arm upper-motor weakness due to damage to motor cortex, nonfluent (Broca’s) aphasia due to damage to Broca’s area. There may also be right face and arm cortical type sensory loss if the infarct involves the sensory cortex. Other deficits include a fluent (Wernicke’s) aphasia due to damage to Wernicke’s area
Describe the deficits seen with an infarct in the right MCA Superficial Division
Left face and arm upper-motor weakness due to damage to motor cortex. Left hemineglect (variable) due to damage to non-dominant association areas. There may also be left face and arm cortical type sensory loss if the infarct involves the sensory cortex
Describe the deficits seen with an infarct in the Left MCA Lenticulostriate Branches
Right pure upper-motor hemiparesis due to damage to the basal ganglia (globus pallidus and striatum) and the genu of the internal capsule on the left side. Larger infarcts extending to the cortex may produce cortical deficits such as aphasia
Right MCA Lenticulostriate Branches
Left pure upper-motor hemiparesis due to damage to the basal ganglia (globus pallidus and striatum) and the genu of the internal capsule on the right side. Larger infarcts extending to the cortex may produce cortical deficits such as aphasia
What areas of the brain are supplied by the posterior cerebral artery?
supplies the occipital lobe, the inferior part of the temporal lobe, and various deep structures including the thalamus and the posterior limb of the internal capsule
Describe the deficits seen with an infarct in the Left posterior cerebral artery
Right homonymous hemianopsia due to damage to left visual cortex in the occipital lobe. Extension to the splenium of the corpus collusom therefore interfering with comunication between the two visual association areas can cause alexia without agraphia. Larger infarcts involving the internal capsule and thalamus may cause right hemisensory loss and right hemiparesis due to disruption of the ascending and descending information passing through these structures
Describe the deficits seen with an infarct in the right posterior cerebral artery
Left homonymous hemianopsia due to damage to right visual cortex in the occipital lobe. Larger infarcts involving the internal capsule and thalamus may cause left hemisensory loss and left hemiparesis due to disruption of the ascending and descending information passing through these structures
