Vocab

• neuron - basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals
• sensory neurons - carry messages from the PNS to the CNS. they have long dendrites and short axons. receives nerve impulses from sensory receptors and convert them into neural impulses (some information is terminated at the spinal cord to prioritise reflex actions)
• relay neurons - connect the sensory neurons to the motor or other relay neurons. they have short dendrites and short axons. in brain and spinal cord
• motor neurons - connect the CNS to effectors such as muscles and glands. they have short dendrites and long axons. projects axons to the PNS. directly (voluntary) or indirectly (involuntary) control muscle movement
• 1. motor neuron
  2. relay neuron
  3. sensory neuron