Harrison's Internal Medicine Chapter 27. Aphasia, Memory Loss, and Other Focal Cerebral Disorders Aphasia, Memory Loss, and Other Focal Cerebral Disorders: Introduction The cerebral cortex of the human brain contains ~20 billion neurons spread over an area of m2. The primary sensory areas provide an obligatory portal for the entry of sensory information into cortical circuitry, whereas the primary motor areas provide final common pathways for coordinating complex motor acts. The primary sensory and motor areas constitute 10% of the cerebral cortex. The rest is subsumed by unimodal, heteromodal, paralimbic, and limbic areas, collectively known as the association cortex (Fig | Chapter 027. Aphasia Memory Loss and Other Focal Cerebral Disorders Part 1 Harrison s Internal Medicine Chapter 27. Aphasia Memory Loss and Other Focal Cerebral Disorders Aphasia Memory Loss and Other Focal Cerebral Disorders Introduction The cerebral cortex of the human brain contains 20 billion neurons spread over an area of m2. The primary sensory areas provide an obligatory portal for the entry of sensory information into cortical circuitry whereas the primary motor areas provide final common pathways for coordinating complex motor acts. The primary sensory and motor areas constitute 10 of the cerebral cortex. The rest is subsumed by unimodal heteromodal paralimbic and limbic areas collectively known as the association cortex Fig. 27-1 . The association cortex mediates the integrative processes that subserve cognition emotion and behavior. A systematic testing of these mental functions is necessary for the effective clinical assessment of the association cortex and its diseases. Figure 27-1 Lateral top and medial bottom views of the cerebral .
