| A | B |
|---|
| Central nervous system | CNS: the neurons in the brain and spinal cord |
| Peripheral Nervous System | PNS: the neurons in the nerves and ganglia in the body |
| Sympathetic Division | the neurons responsible for arousing and preparing the body for energy expending, stressful or emergency situations (fight or flight) |
| Parasympathetic Division | the neurons responsible for restoring the body to a restful state after a stressful situation (rest and digest) |
| Ganglia | groups of neuron cell bodies found outside the central nervous system |
| Nuclei | groups of neuron cell bodies found inside the central nervous system |
| Neuron | the functional unit of the nervous system; the nerve cell |
| Dendrite | the branching end of the nerve cell that receives nerve impulses |
| Axon | the branching end of the nerve cell that transmits nerve impulses |
| Myelin | a layer of tissue around the axon formed by neuroglial cells |
| Nodes of Ranvier | narrow gaps of exposed axon between the myelin sheath |
| Synapse | the junction between the axon terminal of the sending neuron and the dendrite or cell body of the receiving neuron |
| Sensory neuron | the type of neuron that transmits impulses from receptors to the CNS |
| Motor neuron | the type of neuron that transmits impulses to muscle and glands |
| Neurotransmitter | a chemical which carries nerve signals from one neuron to another |
| Resting potential | the difference in electrical charge (potential) between the inside and outside of a nerve cell when an impulse is not being transmitted |
| Action potential | the changes in electrical charge (potential) that occur with the transmission of a nerve impulse along a nerve cell |
| Interneuron | the type of neuron that transmits nerve impulses within the central nervous system |
