4.1 Flashcards
Vertical columns
specific functional units
Afferents of the cerebral cortex
Cortex to cortex connections
Corticocortical excitatory fibers (which release glutamate or aspartate) from cortical areas
Most of these afferents come from thalamus and they travel to the cortex through the thalamocortical radiations.
Efferents
Pyramidal and fusiform cells
Association
Projection
Commisural
When to use cerebral angiogram
If concerned about aneurysm
Arteriorvenous malformation (AVM)
Stroke
Stenosis/occlusion of cerebral arteries
The process of producing speech
Complex and multilevel
1. Concept in mind
2. Organize how to communicate and select words to express concept
3. Organize muscles of mouth, tongue, and larynx to generate sound and add tonality
The motor speech system includes…
Cerebellum
Basal nuclei
Somatic muscles
Dysarthria
Incoordination and/or slowness of speech
Dysarthria occurs when the muscles you use for speech are weak or you have difficulty controlling them.
Cerebellar dysarthria
Ataxic
A slowing down of articulatory movements, increased variability of pitch and loudness, monotonous and “scanning” speech, and articulatory impreciseness.
Basal nuclei related dysarthria
Hyperkinetic or hypokinetic
UMN or LMN
Muscle weakness
Aphasia
Absence of speech
Involves multiple anatomic regions
Can be a result of damage to any area of the cortex
The characteristics of the aphasia can reveal the area of the lesion
Broca’s aphasia
Middle cerebral artery serves this area.
Difficulty expressing thought
Nonfluent
Speaks slowly and with difficulty
Spoken and written language comprehension is relatively preserved
Wernicke’s aphasia
Unilateral lesion in the dominant hemisphere
Difficulty comprehending the spoken word and is unable to read
Even if speech is fluent the combination and order of the words is meaningless and makes no sense to him or others (fluent paraphasia speech)
Individual is unaware of his deficiencies.
Global aphasia
Unable to comprehend what he hears of reads
Cannot write
Unable to formulate normal language
Apraxia of speech
Inability to execute
Neurological damage leading to apraxia of speech can occur in the following area:
- Broca’s area
- supplementary motor area
- insula (insular cortex)
- basal nuclei
Internal carotid
anterior and middle cerebral artery
Association fibers
Parietal, occipital, and temporal lobes are connected with the frontal lobe via prominent fasciculi composed of association fibers spanning the 4 lobes
- consist of axons arising from small pyramidal cells, primarily from layer I and II.
Commisural fibers
Arise in one cerebral hemisphere and cross the midline to terminate in the corresponding cortical area of the contralateral hemisphere
- avenue of communication between the corresponding cortical areas of the two hemispheres
Projection fibers
Consist of both afferent and efferent fibers to and from the cerebral cortex, that connect it to the thalamus, basal nuclei, brainstem, and spinal cord
Internal capsule
A massive, fan-shaped collection of fibers that connect the thalamus to the cerebral cortex
Corona radiata
A continuation of the internal capsule, containing afferent and efferent fibers to and from the cerebral cortex.
Lobes of the cerebrum
Frontal
Parietal
Temporal
Occipital
Limbic
Where do the signals to the PAC come from?
Receives information between from both ears by way of the medial geniculate nucleus of the thalamus and then sends projections to the contralateral side via the corpus callosum.
Describe the connections between the PAC and secondary areas.
The sensory association areas (PAC) receive inputs from the primary sensory areas and further process, integrate, and interpret the incoming sensory input.
The secondary sensory areas surround the primary sensory areas.
Compare functions of Wernicke’s and Broca’s areas
Wernicke’s area: consists of auditory association cortex. It is referred to as the receptive (sensory) language area, general interpretive area, or the gnostic area. It plays an important role in the comprehension and formulation of language.
Broca’s area: the motor speech area; only functions in the initiation of a sequence of complex movements which are essential in the production of speech, but also has expressive language capacities.
The “where speech path carries signals from the PAC to the ipsilateral parietal lobe. This is an example of…
Association fibers
Describe the function of Wernicke’s area.
Comprehension and formulation of language
Describe Broca’s area lesion.
Only uses main or necessary words of a sentence
Describe Wernicke’s area lesion.
The combination and order of the words selected is meaningless and makes no sense
Describe global aphasia lesion.
Unable to comprehend what he hears or reads, cannot write, and in addition is unable to formulate normal language
Basilar artery
posterior cerebral artery
Function of frontal lobe
Motor control
Cognitive functions
Processing emotions
Motor aspects of language
Function of parietal lobe
Sensation
Process touch, pressure, pain, temperature, and proprioception
Function of temporal lobe
Process hearing, memory, emotions, and sensory aspects of speech
Function of occipital lobe
Process visual information
Function of limbic lobe
Process emotions
