2.  Found around the segments of myelin sheath.  They form the myelin sheath by rotating several times around the axon.  Thus forming a series of rings of phospholipid which will be the myelin sheath. Rawan turky

4.  Act as insulator for nerve impulse.  Regeneration of neurones after injury.  Formation of myelin sheath in peripheral nerves. Rawan turky

5.  The point of contact between the processes of the neurons.  The synapse is composed of three parts:  1. Presynaptic terminal: (End bulb)  The terminal part of axon delivers the impulse to the synaps.  It contain many mitochondria and neurovisicles or neurotransmitter rich in Acetylcholine. Rawan turky

6.  Synaptic cleft :  The distance between 2 synaptic membrane.  Filled with chemical transmitter.  It contain enzymes that destroy the molecules of transmitter.  Postsynaptic membrane:  The membrane of other dendrite.  Type of synapse:  Axo-dendritic synapse.  Axo-somatic sypase.  Axo-axonic synapse.

8.  The nerve trunk is formed of collections of axons arranged in bundle bound together by C.T.  Epineurium: surround the whole N.T.  Perineurium: surround the nerve bundle.  Endoneurium: surround the nerve fiber. Rawan turky

9.  Composed of nerve cells and nerve fiber surrounded by C.T. called capsule  There are 2 types :  Spinal ganglia.  Autonomic ganglia.  Sympathatic ganglia.  Parasympathatic ganglia Rawan turky

10.  Spinal ganglia are exist beside the spinal cord at its both side.  Formed of pseudounipolar nervw cell.  Each cell is surrounded by small satellite cell, which are supportive and nutritive in functions to nerve cell. Rawan turky

12.  Sympathatic ganglia :  Exist in several region of the body, formed of multipolar stellate-shaped nerve cells, surrounded by few satellite cells Rawan turky

13.  Represent the supporting tissue, instead of C.T. between the neurons of C.N.S.  Neuroglia may be classified into:  Neuroglia proper.  Macroglia or Astrocyte.  Microglia or Mesoglia.  Oligodendroglia Rawan turky

14.  Other types of Neuroglia  Ependymal cell  Satellite cells  Neurolemmal or Schwann cell.  Spongioblast cell Rawan turky