two sentences demonstrating your knowledge of the terms proximal and distal
utilizing the terms found in your book on specific body regions and body
cavities. Make sure you utilize
different body regions and cavities for each sentence
axon of a peripheral nerve is separated from the cell body, the distal portion
deteriorates and the fragments are removed by macrophages. The proximal end then
develops new sprouts, and nerve growth factors from surrounding neuroglia cause
the sprouts to grow. At the same time, remaining Schwann cells proliferate and
surround the new axon. If a sprout grows into the remaining basement membranes
of the original tract, the new fiber may rejoin with its original connection.
If the injured axon is from a neuron in the CNS, the lack of a myelin sheath
prevents the new fiber from being guided to its original connection. Therefore,
regeneration in the CNS is very unlikely. An injury to the cell body of a
neuron usually causes death to the entire fiber, and no regeneration will
Oct 8th, 2014
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