| A | B |
|---|
| Neuron | nerve cell |
| glial cell | cells that support, protect and nourish neurons |
| myelin sheath | a layer of insulation that protects the axon and increases the speed of transmission |
| axon | the long nerve fiber that conducts impulses |
| synapse | the communication point between neurons |
| neurotransmitters | chemicals that move from one neuron to another |
| white matter | brain matter composed mainly of myelin-covered axons |
| grey matter | Brain matter made up of neuron cell bodies |
| hypothalmus | Controls body's autonomic processes |
| thalmus | brain's relay station |
| cerebellum | controls balance and movement |
| cerebrospinal fluid | liquid produced in the brain ventricles that provides energy for the brain and spinal cord |
| ventricles | fluid filled areas of the brain |
| meninges | three layers that cover the brain |
| spinal cord | cable of nerves descending from the brain stem down to the lumbar region |
| spinal nerves | 31 pairs of nerves that exit from the spinal cord to the entire body |
| sensory nerves | nerves that carry impulses about sensations |
| motor nerves | nerves that carry impulses to voluntary skeletal muscles |
| autonomic nerves | nerves that regulate the internal organs and glands |
| cranial nerves | 12 pairs of nerves that serve the head and neck |
| sympathetic nervous system | prepares the body for stress |
| parasympathetic nervous system | maintains or restores energy |
| limbic system | fight or flight response |
| brain stem | controls sleep, reflexes, breathing and heart rate |
