| A | B |
|---|
| CNS | central nervous system (brain and spinal cord) |
| PNS | peripheral nervous system (spinal and cranial nerves) |
| ANS | autonomic nervous system (sympathetic and parasympathetic) |
| ganglion | group of cell bodies in peripheral nervous system |
| nerve | bundle of nerve fibers (axons) in peripheral nervous system |
| functional classification of neurons | sensory (afferent), interneurons and motor (efferent) |
| neurosoma | cell body of neuron |
| dendrites | receive nerve impulses |
| axons | sends nerve impulses away from cell body |
| axon hillock | where axon originates |
| axon terminal | end of axon which forms a synapse with another neuron |
| structural classification of neurons | multipolar, bipolar and unipolar |
| neuroglia | glial cells, outnumber neurons in the nervous system 10-1. Have a supportive role |
| oligodendrocytes | glial cell in CNS that makes a myelin sheath around axons |
| ependymal cell | glial cell found in CNS, makes cerebrospinal fluid |
| microglia | glial cell found in CNS, acts as a macrophage |
| astrocytes | glial cell found in CNS, most abundant, many functions: supportive framework, helps form blood brain barrier, provide nourishment, regulate composition of tissue fluid etc |
| schwann cells | glial cell in PNS makes myelin sheath |
| satellite cells | glial cell in PNS, provide insulation around somas |
| resting membrane potential | a charge difference across a neuron membrane at rest (-70 millivolts) |
| depolarization | a change in membrane potential where sodium rushes in the cell making it more positive (+30 millivolts) |
| local potential | a short range change in membrane potential (localized) |
| hyperpolarize | when the membrane goes beyond resting membrane potential, or becomes more negative inside (makes it difficult for an action potential to occur) |
| action potential | when a membrane depolarizes significantly, reaches a point called threshold (sodium rushes in) |
| repolarization | the membrane returns to the resting membrane potential |
| refractory period | a period of time where the membrane cannot be stimulated again (absolute and relative) |
| saltatory conduction | fast nerve transmission on a myelinated axon |
| EPSP | excitatory post synaptic potential (results from sodium entering and the inside of the cell becoming less negative) |
| IPSP | inhibitory post synaptic potential (results when negative ions enter the cell and it becomes more negative) |
| temporal summation | intense stimulation by one neuron over and over |
| spatial summation | several neurons simultaneously stimulate one neuron |
