#1
12th April 2016, 03:11 PM
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Study Of Nervous System
Sir I am a bio student and I want to know about the nervous system as it’s a topic in our \ syllabus and I am having some difficulty to understand it so can you please tell me the same
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#2
12th April 2016, 03:12 PM
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Re: Study Of Nervous System
Hey buddy The nervous system derives its name from nerves, which are cylindrical bundles of fibers (the axons of neurons), that emanate from the brain and spinal cord, and branch repeatedly to innervate every part of the body. The nervous system is the part of an animal's body that coordinates its voluntary and involuntary actions and transmits signals to and from different parts of its body. Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrate species it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS) The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nervous system Division of the vertebrate nervous system The vertebrate nervous system can also be divided into areas called grey matter ("gray matter" in American spelling) and white matter. Grey matter (which is only grey in preserved tissue, and is better described as pink or light brown in living tissue) contains a high proportion of cell bodies of neurons. White matter is composed mainly of myelinated axons, and takes its color from the myelin. White matter includes all of the nerves, and much of the interior of the brain and spinal cord |