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Beyond protection the meninges tissue is also important for the [[circulatory]] health of the central nervous system. The veins and arteries that serve the CNS are located in the subarachnoid space. There are also large, low-pressure blood vessels that serve as the return path for cerebral venous blood located in the dura mater.  

Beyond protection the meninges tissue is also important for the [[circulatory]] health of the central nervous system. The veins and arteries that serve the CNS are located in the subarachnoid space. There are also large, low-pressure blood vessels that serve as the return path for cerebral venous blood located in the dura mater.  

The CNS contains several cavities called the [[ventrical system]]. Tissue surronding the ventrical system is the primary producer of [[cerebrospinal fluid]] which surrounds the CNS providing a medium for communication between [[neurons]] and as a cushion in case of trauma.  

The CNS contains several cavities called the [[ventrical system]]. Tissue surrounding the ventrical system is the primary producer of [[cerebrospinal fluid]] which surrounds the CNS providing a medium for communication between [[neurons]] and as a cushion in case of trauma.  

Neurons and [[axons]] are distributed non-uniformly through the CNS. The [[soma|cell body]] and [[dendrites]] of the neurons cluster in [[cortical]] regions which are essentially flattened sheets of cells called [[laminae]]. These areas are located primarily on the cerebral hemispheres or in areas beneath the surface of all the sub-divisions of the CNS called [[nuclei]]. Axons are then distributed through out the system in regions called tracts. In live tissue the regions populated by cell bodies and dendrites appear gray while the tract's of axons appear white due to myelin sheaths. These areas are called [[gray matter]] and [[white matter]] respectively.

Neurons and [[axons]] are distributed non-uniformly through the CNS. The [[soma|cell body]] and [[dendrites]] of the neurons cluster in [[cortical]] regions which are essentially flattened sheets of cells called [[laminae]]. These areas are located primarily on the cerebral hemispheres or in areas beneath the surface of all the sub-divisions of the CNS called [[nuclei]]. Axons are then distributed through out the system in regions called tracts. In live tissue the regions populated by cell bodies and dendrites appear gray while the tract's of axons appear white due to myelin sheaths. These areas are called [[gray matter]] and [[white matter]] respectively.

The cerebral hemisphere is a highly developed and complex structure. Its divided into four major sections: [[cerebral cortex]], [[hippocampal formation]], [[amygdala]], and the [[basal ganglia]]. Most behavior that is viewed as uniquely human is controlled by these four structures.  

The cerebral hemisphere is a highly developed and complex structure. Its divided into four major sections: [[cerebral cortex]], [[hippocampal formation]], [[amygdala]], and the [[basal ganglia]]. Most behavior that is viewed as uniquely human is controlled by these four structures.  

The hippocampal formation is primarily used in memory and learning, the amygdala controls emotion and the organisms response to stress. Together with some parts of the brain stem these structures make up the [[limbic system]] which plays a very large role in mood and psychological disfunctions. The basal ganglia is important in movement and muscle control, it is the area of the brain that is damaged with [[Parkinson's Disease]]. It is also important in cognition and emotion and seems to be a key area involved in [[addiction]].  

The hippocampal formation is primarily used in memory and learning, the amygdala controls emotion and the organisms response to stress. Together with some parts of the brain stem these structures make up the [[limbic system]] which plays a very large role in mood and psychological dysfunctions. The basal ganglia is important in movement and muscle control, it is the area of the brain that is damaged with [[Parkinson's Disease]]. It is also important in cognition and emotion and seems to be a key area involved in [[addiction]].  

The cerebral cortex is located on the surface of the brain and has a highly complex three dimensional structure of convoluted nervous tissue. It is essentially a long sheet that has been folded up again and again. These folds are thought to be an [[adaptation]] to squeezing in large amounts of nervous tissue in the limited space of the cranial skull. These folds create a wave pattern with the elevated portion of the tissue being called [[gyri]] and the separations between called [[sulci]]. Some sulci are particularly deep and called fissures. The two hemispheres of the brain are separated by a large fissure called the [[sagittal fissure]]. The hemispheres are connected by a structure called the [[corpus callosum]].  

The cerebral cortex is located on the surface of the brain and has a highly complex three dimensional structure of convoluted nervous tissue. It is essentially a long sheet that has been folded up again and again. These folds are thought to be an [[adaptation]] to squeezing in large amounts of nervous tissue in the limited space of the cranial skull. These folds create a wave pattern with the elevated portion of the tissue being called [[gyri]] and the separations between called [[sulci]]. Some sulci are particularly deep and called fissures. The two hemispheres of the brain are separated by a large fissure called the [[sagittal fissure]]. The hemispheres are connected by a structure called the [[corpus callosum]].