Nervous System

• Nervous System is the Control System of the body
• Nervous System has 2 types:

  1. CNS (Central Nervous System)
  2. PNS (Peripheral Nervous System)
• Nerve Cells have Synaptic Space
• Main Parts

  1. PNS - Nerve and Ganglion
  2. CNS - Brain and Spinal cord
• The need of Nervous System:

  1. Keep us informed about the outside world.
  2. Help us think, remember, reason, etc.
  3. Controls all voluntary actions.
  4. Regulates all involuntary actions.
• A Neurons

  A Neurons consists of the following parts:

  1. The Cell Body
  2. Dendrites
  3. Axon
• The Cell Body


  -It is also called CYTON or PERIKARYON.

  -It contains a nucleus with cytoplasm.
• Dendrites


  -They are branched structures of the human/cell body.

  -They help to conduct the impulses to the cell body.
• Axon


  -It is a ELONGATED DENDRITES. It is surrounded by the MYELIN, SHEATH, which is again covered by NURDLEMMA.

  -The MYELIN SHEATH has gaps through out its lengths called the NOSED OF RANVIER.

  -The end portion are swollen like bulbs called NEUROTRANSMITTERS, which store chemicals.
• Nerve Cell


  The nervous system consists of the brain, spinal cord, sense receptors and the nerve. -> It helps to perceive and send messages to the parts of our body as required.