Neurons

• Neurons are cells in our body responsible for transmitting electrical signals through the nervous system
• Sensory neurons carry signals from the body to the brain
• Lobotomies


  Splitting the connection of the prefrontal cortex leads to behavioral changes
• Neurons


  Cells in our body responsible for transmitting electrical signals through the nervous system
• Types of neurons


  • Sensory neurons carry signals from the body to the brain and spinal cord
  • Interneurons connect sensory neurons with motor neurons
  • Motor neurons control the movement of the body
• Sensory neurons


  • Found in sensory organs such as skin, tongue, ears, eyes, nose
  • Also found in muscles or the lining of organs
• Motor neurons


  • Coordinate muscles and ensure arms and legs move together
  • Transmit impulses from the brain and/or spinal cord to muscles and glands
• Function of a neuron

  Transmit nerve impulses along the length of an individual neuron and across the synapse into the next neuron
• Electrical signals transmitted by neurons

  • Called action potentials
• Transmission of a signal within a neuron

  Occurs in one direction, from dendrite to axon terminal
• Synapses
• Transmission across a synapse

  1. Neurotransmitter molecules are packaged into membranous vesicles and concentrated at the presynaptic terminal

  2. Depolarization of the presynaptic membrane allows Ca2+ ions to flow into the terminal

  3. Fusion of vesicles with the presynaptic membrane releases the transmitter in certain amounts and diffuses across the synaptic cleft
• Neurons


  The basic structural unit of the nervous system, responsible for sending and receiving impulses throughout the NS
• Structure of Neurons


  • Cell Body
  • Dendrites
  • Axon
  • Axon Terminal
  • Schwann Cell
  • Neurilemma
  • Myelin sheath
  • Node of Ranvier
• Types of Neurons - Function

  • Motor
  • Sensory
  • Interneuron
• Nerve Impulse


  The message that travels along a nerve fibre, transmitted very quickly, making it possible for the body to respond rapidly to a change in the internal or external environment, an electrochemical change because it involves a change in the electrical voltage that is brought about by the concentration of ions inside and outside the cell membrane
• Synapse


  Neurons do not join, there is a very small gap known as a synapse, occurs between a branch at the end of an axon and a dendrite or the cell body of another neuron, messages are carried across the synapse via chemical messengers (neurotransmitters) from the pre-synaptic to post-synaptic neuron