nervous + endocrine system

• Explain why neurones can only travel in one direction at a synapse?

  • the synaptic vesicles containing the neurotransmitter are only present on the presynaptic membrane
  • receptors are only present on postsynaptic membrane
  • diffusion of neurotransmitters mean they can only go from high to low concentration
  • the binding of neurotransmitters to receptors causes transmission of action potential
• Briefly outline how excitation and inhibition are involved in synaptic transmission.

  • Neurotransmitters can be excitatory or inhibitory
  • If the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse
  • summation is the idea that excitatory and inhibitory influences are summed so that if the net effect is inhibitory, an impulse is less likely to be fired
• Outline the central nervous system

  • main control system for life functions
  • includes the brain which is involved with thinking and processes information from the PNS
  • spinal chord transmits information between the brain and PNS
• Outline the peripheral nervous system

  • transmits information between the environment and central nervous system
  • can be split into the autonomic and somatic nervous system
• Autonomic nervous system

  • responsible for involuntary bodily activities such as heart rate
• sensory neurones

  • send information from the senses to the brain
  • receptors would detect a stimulus
  • that information would be passed in via the peripheral nervous system to the brain (CNS)
• Relay neurones

  • connect with other neurones
  • mostly found in the CNS
• Motor neurones

  • send information from the brain to the effectors
  • this causes an effect
• Excitatory neurotransmitters

  • neurotransmitters that increase the rate of firing in the post synaptic neurones