function of neurons

• what is the purpose of the motor neuron?


  They carry action potentials from the central nervous system to an effector like muscles or glands
• What is the purpose of the sensory neuron?


  they carry action potentials from a sensory receptor to the central nervous system
• What is the purpsoe of the relay neuron?


  They connect sensory and motor neurons
• what are the general features of a neuron?

  Very long- transmit action potentials over long distances

  Cell surface membrane has many gated ion channels to control entry/exit of sodium, potassium or calcium

  Neurones maintain a potential difference across their membrane

  Cell bodies contain the nucleus, mitochondria and ribosomes

  Lots of dendrites connect to other neurones and carry impulses to the cell body

  Axons carry impulses away from cell body

  Mylelin sheet to insulate the cell, speeding up the transmission.
• What type of neuron is this?

  motor neuron

  
• what type of neuron is this?

  sensory neuron

  
• what type of neuron is this?

  Relay neuron

  
• motor neurons have their cell body in the central nervous system and have a long axon that carries the action potential out to the effector
• Sensory neurons have a long dendron carrying the action potential from a sensory receptor to the cell body, which is positioned just outside of the central nervous system; they have a short axon that carries the action potential into the central nervous system
• Relay neurons connect the sensory and motor neurons. they have many short dendrites and a short axon. the number of dendrites and the number of divisions of the axon is variable. Relay neurons are an essential part of the nervous system because they conduct impulses in coordinated pathways