Synapse and transmission of nerve impulse, all or none character of nerve impulse, transmission of excitatory state from nerve to effectors tissue

Neurons

  • Structural and functional unit of nervous system
  • Neurons initiates and transmits nerve impulse to other cell
  • Neurons are present in CNS, PNS and sensory organs
  • Neurons consists of Dendrites, cell body, axon

 

Structure of neuron

 

What Is a Neuron? – Definition, Structure, Parts and Function

 

Primarily, contains dendrites, cell body and axon.

a. Dendrites

  • Numerous, small, wide, fine branched like structure
  • Carry impulse towards cell body

 

b. Cell body

  • Core part of neuron
  • Give rise to dendrites and axon
  • Contain nucleus and other organelles
  • Neurofibrils help to pass impulse to and from the cell body

 

c. Axon

  • Single long processes
  • Conduct impulse away from cell body
  • Communicate with other neurons through synapse.

 

d. Terminal end

  • Terminal part of axon which is neurosecretory in function.

      #note

Myelinated nerve fibre:

  • Axon surrounded by nerve fibre
  • Sheath are interrupt at regular interval called node of ranvier
  • Conduct nerve impulse at high speed

 

Non myelinated nerve fibre:

  • Myelin sheath is absent
  • Conduct nerve impulse at slower rate
PreviousNext