When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Grey matter - Wikipedia

    en.wikipedia.org/wiki/Grey_matter

    Grey matter, or gray matter in American English, is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and unmyelinated axons), glial cells (astrocytes and oligodendrocytes), synapses, and capillaries.

  3. White matter - Wikipedia

    en.wikipedia.org/wiki/White_matter

    White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found in almost all long nerve fibers, and acts as an electrical insulation.

  4. Nervous system - Wikipedia

    en.wikipedia.org/wiki/Nervous_system

    Diagram showing the major divisions of the vertebrate nervous system Horizontal section of the head of an adult female human, showing skin, skull, and brain with gray matter (brown in this image) and underlying white matter. The nervous system of vertebrates (including humans) is divided into the central nervous system (CNS) and the peripheral ...

  5. Ramus communicans - Wikipedia

    en.wikipedia.org/wiki/Ramus_communicans

    Gray ramus communicans; White ramus communicans; The grey and white rami communicantes are responsible for conveying autonomic signals, specifically for the sympathetic nervous system. Their difference in colouration is caused by differences in myelination of the nerve fibres contained within, i.e. there are more myelinated than unmyelinated ...

  6. Nervous tissue - Wikipedia

    en.wikipedia.org/wiki/Nervous_tissue

    Nervous tissue, also called neural tissue, is the main tissue component of the nervous system.The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the brain and spinal cord, and the peripheral nervous system (PNS) comprising the branching peripheral nerves.

  7. Central nervous system - Wikipedia

    en.wikipedia.org/wiki/Central_nervous_system

    The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina.The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts.

  8. White ramus communicans - Wikipedia

    en.wikipedia.org/wiki/White_ramus_communicans

    The white ramus communicans (pl.: rami communicantes) from Latin ramus (branch) and communicans (communicating) is the preganglionic sympathetic outflow nerve tract from the spinal cord. Each of the thoracic, and the first and second lumbar nerves contribute a white ramus communicans to the adjoining sympathetic ganglion , unlike the gray rami ...

  9. Gray ramus communicans - Wikipedia

    en.wikipedia.org/wiki/Gray_ramus_communicans

    Each spinal nerve receives a branch called a gray ramus communicans (pl.: rami communicantes) from the adjacent paravertebral ganglion of the sympathetic trunk. The gray rami communicantes contain postganglionic nerve fibers of the sympathetic nervous system and are composed of largely unmyelinated neurons.