NEURONS

• What are sensory neurons?


  Found in receptor e.g. eyes and ears, and carry nerve impulses to the spinal cord and brain from sensory receptors in the PNS.

  When nerve impulses reach the brain, they're translated into sensation e.g. vision and hearing.

  However, some neutrons terminate in the spinal cord to allow reflex actions to take place without delay.
• what are relay neurons?


  Found between sensory input and motor output/response. Found in the brain and spinal cord and allow motor and sensory neurons to communicate.

  They carry messages from one part of the CNS to another.

  Usually have shorter dendrites and axons than motor and sensory neurons.
• What are motor neurons?


  Found in the CNS and control muscle movements. When motor neurons are stimulated they release neurotransmitters that bind to receptors or muscles.

  Allows for both voluntary and involuntary movements through the innervation of glands and effector muscles.

  Carry messages from CNS to directly or indirectly control muscles.
• What are dendrites?


  Receive signals from other neurons or sensory receptor cells. They're typically connected to the cell body.

  Referred to as the control centre-contains nucleus.
• What are axons?


  A long slender fibre that forms an electrical signal known as an action potential to carry nerve impulses away from the cell body towards soon terminals, which connect neurons to other neurons using a process called synaptic transmission.
• What does a myelin sheath do?

  Insulates axon so impulses travel faster.
• What is an axon terminal?

  Connects the neuron to other neurons (or directly to organs), using a process called synaptic transmission.