Chapter 1

• neuron("nerve cell")


  basic unit of the nervous system, each composed of receptive extensions, called dendrites, an integrating cell body, a conducting axon, and a transmitting axon terminal
• glial cells ("glia")


  nonneuronal brain cells that provide structural, nutritional, and other types of support to the brain
• synapse


  the cellular location at which information is transmitted from a neuron to another cell
• input zone

  the part of a neuron that receives information from other neurons or from specialized sensory structures
• dendrite


  an extension of the cell body that receives information from other neurons
• integration zone


  the part of a neuron that initiates neural electrical activity
• cell body ("soma")


  the region of a neuron that is defined by the presence of the cell nucleus
• conduction zone


  the part of the neuron—typically the axon—over which the action potential is actively propogated
• axon ("nerve fiber") 


  a single extension from the nerve cell that carries action potentials from the cell body toward the axon terminals
• axon collateral


  a branch of the axon
• output zone


  the part of a neuron at which the cell sends information to another cell
• axon terminal ("synaptic bouton")


  the end of an axon or axon collateral, which forms a synapse onto a neuron or other target cell and thus serves as the output zone
• motor neuron ("motoneuron")


  a neuron that transmits neural messages to muscles (or glands)
• sensory neuron


  a nerve cell that is directly affected by changes in the environment, such as light, odor, or touch
• interneuron 


  a nerve cell that is neither a sensory neuron nor a motor neuron; interneurons receive input from and send output to other neurons
• multipolar neuron 


  a nerve cell that has many dendrites and a single axon
• bipolar neuron


  a nerve cell that has a single dendrite at one end and a single axon at the other end
• unipolar neuron ("monopolar neuron")


  a nerve cell with a single branch that leaves the cell body and then extends in two directions: one end is the input zone, and the other end is the output zone
• presynaptic


  referring to the "transmitting" side of a synapse
• postsynaptic


  referring to the region of a synapse that receives and responds to neurotransmitter
• presynaptic membrane


  the specialized membrane on the axon terminal of a nerve cell that transmits information by releasing neurotransmitter
• synaptic cleft


  the space between the presynaptic and postsynaptic neurons at a synapse
• postsynaptic membrane


  the specialized membrane on the surface of a neuron that receives information by responding to neurtransmitter from a presynaptic neuron
• synaptic vesicle


  a small, spherical structure that contains molecules of neurotransmitter
• neurotransmitter ("synaptic transmitter," "chemical transmitter," or "transmitter")

  the chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons
• neurotransmitter receptor ("simply receptor")


  a specialized protein that selectively senses and reacts to molecules of a corresponding neurotransmitter or hormone
• neurplasticity ("neural plasticity")


  the ability of the nervous system to change in response to experience or the environment
• axon hillock


  the cone-shaped area on the cell body from which the axon originates
• innervate


  to provide neural input to
• axonal transport


  the transportation of materials from the neuronal cell body toward the axon terminals, and from the axon terminals back toward the cell body
• oligodendrocyte


  a type of glial cell that forms myelin in the central nervous system
• schwann cell


  a type of glial cell that forms myelin in the PNS
• myelin


  the fatty insulation around an axon, formed by glial cells; this sheath boosts the speed at which nerve impulses are conducted
• node of Ranvier


  a gap between successive segments of the myelin sheath where the axon membrane is exposed
• astrocyte


  a star-shaped glial cell with numerous processes (extensions) that run in all directions
• microglial cells ("microglia")


  extremely small motile glial cells that remove cellular debris from injured or dead cells
• gross neuroanatomy


  anatomical features of the nervous system that are apparent to the naked eye
• central nervous system (CNS)


  the portion of the nervous system that includes the brain and the spinal cord
• peripheral nervous system (PNS)


  the portion of the nervous system that includes all the nerves and neurons outside the brain and spinal cord
• nerve


  a collection of axons bundled together outside the CNS