The anatomy of the cerebral hemispheres and sensory systems Flashcards
In which lobes are the:
- Auditory Cortex
- Sensory Cortex
- Motor Cortex
- Visual Cortex
- Wernicke’s Area
- Broca’s Area?
- Auditory Cortex = temporal
- Sensory Cortex = parietal
- Motor Cortex = frontal
- Visual Cortex = occipital
- Wernicke’s Area = frontal
- Broca’s Area = temporal, parietal, occipital.
What do the following fibres connect?
- Association
- Commissural
- Projection
- Association neurons connect different parts of the same hemisphere.
- Commissural neurons connect the two hemispheres.
- Projection neurons connect either the hemispheres to the brainstem and spinal cord or vice versa.
What is the major commissural connection between the left and right hemispheres called?
The major commissural connection is the corpus callosum.
What is the effect of damage to the prefrontal cortex?
Damage to prefrontal cortex > antisocial behaviour (lack of self-care and personal hygiene, puerile jocularity (= inappropriate laughter), aggression, lack of turn taking in conversation etc.
Where is the primary motor cortex?
Precentral gyrus
Where is the primary sensory cortex?
Postcentral gyrus
How are the primary sensory and motor areas arranged?
Both sensory and motor cortex arranged SOMATOTOPICALLY = arranged in same way as body but upside down and on opposite side of body so legs are at top near midline and head is at bottom near lateral fissure.
Area given to each body area is proportional to its importance so key sensory areas like fingers and lips have big areas and important motor areas like tongue and fingers have big areas.
If the right motor cortex is damaged:
A. Which side of the head will be affected?
B. Which side of the body will be affected?
A. Both sides – showing as muscular weakness = paresis.
B. Contralateral side – upper motor neuron lesion = spastic paralysis.
Predict the likely effects of damage to the dominant parietal association cortex:
Usually affects abstract abilities, agraphia, alexia, anomia usually with apraxia, inattention to contralateral side.
Predict the likely effects of damage to the non-dominant parietal association cortex:
usually affects visuospatial abilities - can’t recognise faces, can’t draw simple figures, dressing apraxia and inattention to opposite side.
What are the major functions of the temporal lobe?
Temporal lobe contains memory cortex, auditory cortex and several areas involved in linguistic decoding.
Which tracts carry pain and temperature information?
Pain and temperature sensations ascend in the anterolateral (spinothalamic) tracts.
What information is carried in the dorsal column pathways?
Dorsal column pathways carry fine/discriminative touch and proprioception from joints and muscles.
