Brain cerebrum lobes

Named for the bones of the cranium under which they lie, the lobes are conspicuously defined by prominent sulci of the cortex, which have a relatively constant position in human brains. Each lobe is specialized for different activities (see Figure 6.3). Located in the anterior portions of the hemispheres, the frontal lobes are responsible for voluntary motor activity, speaking ability, and higher intellectual activities. The parietal lobes, which are posterior to the frontal lobes, process and integrate sensory information. The occipital lobes, located in the posterior-most aspects of the cerebrum, process visual information, and the temporal lobes, located laterally, process auditory information. 

As we move forward, it will prove helpful to get some basic aspects of the human nervous system in place. An enormous amount of work has gone into making associations between brain anatomy and function. Starting with the three main parts of the brain, we know that the cerebrum is the seat of consciousness. It is divided into two hemispheres, which are linked by the corpus callosum. In a very general sense, the left hemisphere is associated with intellectual and the right hemisphere with emotional responses. Within the cerebrum, one can associate a number of brain areas (the prefrontal, frontal, temporal, parietal, and occipital lobes, for example) with functions including vision and hearing. One can make crude maps in which function is mapped onto brain structure. 

The largest and most rostral aspect of the brain is the cerebrum (see Fig. 5-1). The cerebrum consists of bilateral hemispheres, with each hemisphere anatomically divided into several lobes (frontal, temporal, parietal,... 

The back portion of the human cerebrum, comprised by the parietal (P), temporal (T), and occipital (O) lobes, is the sensuous portion of our brain. It is devoted to processing all the sights, sounds, smells, tastes, and touch-based sensations that we consciously experience. It connects those experiences to each other and with our memories and emotions. So thank your parietal lobes for being able to feel the hands of your masseur (or masseuse), your occipital lobes for seeing him, and your temporal lobes for hearing his voice. 

To successfully perform this complex job, our frontal lobes must keep a mental model of the world in mind (working memory) and then depend upon the sensuous cerebrum to convey to it not only our memories of the past, but also our moods. Throughout evolution, moods have played a critical role in reflecting what s happening in our environment (is it presently peaceful, or threatening our existence ). The back portion of our brain then selects memories that are most useful and appropriate and conveys them to the front portion of our brain to aid performance of our executive functions. 

Grossly, Scriba (1950) found moderate bilateral atrophy of the anterior poles of the frontal lobes of the brain. Crawford (1958) reported enormous dilation of the vessels of the brain base, particularly of vertebral, left carotid and basilar arteries, the diameter of the latter vessel being 12,5 mm. Moderate generalized edema of cerebrum and cerebellum was described by Falck and Weicksel (1957). Areas of ischemic degeneration have been seen in cross sections (Scriba 1950, Wallace 1958). 

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