Atalas de neuro

Section A

ORIENTATION
INTRODUCTION
An understanding of the central nervous system — the CNS — and how it functions requires knowing its component parts and their specialized operations, and the contribution of each of the parts to the function of the whole. The first section of this atlas introduces the student to the CNS from an anatomical and functional viewpoint. The subsequent section (Section B) will use these components to build the various systems, such as the sensory and motor systems. The blood supply and the detailed anatomical organization are found in Section C. Emotional behavior is discussed in Section D. cessing of information. These neurons are called interneurons, and more complex information processing, such as occurs in the human brain, is correlated with the dramatic increase in the number of interneurons in our brains. Communication between neurons occurs almost exclusively at specialized junctions called synapses, using biological molecules called neurotransmitters. These modify ion movements across the neuronal membranes of the synapse and alter neurotransmission — they can be excitatory or inhibitory in their action, or modulate synaptic excitability. The post-synaptic neuron will modify its firing pattern depending on the summative effect of all the synapses acting upon it at any moment in time. The action of neurotransmitters depends also on the specific receptor type; there is an ever increasing number of receptor subtypes allowing for even more complexity of information processing within the CNS. Drugs are being designed to act on those receptors for therapeutic purposes. Much of the substance of the brain consists of axons, also called fibers, which connect one part of the brain with other areas. These fibers function so that the various parts of the brain communicate with each other, some going a short distance linking neurons locally and others traveling a long distance connecting different areas of the brain and spinal cord. Many of