Term
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Definition
| a neuron that detects changes in the external or internal environment and sends information about these changes to the CNS |
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Definition
| a neuron located within the CNS that controls the contraction of a muscle of the secretion of a gland |
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Term
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Definition
| a neuron located entirely within the CNS |
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Term
| central nervous system (CNS) |
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Definition
| the brain and spinal cord |
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Term
| peripheral nervous system (PNS) |
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Definition
| the part of the nervous system outside the brain and spinal cord, including the nerves attached to the brain and spinal cord |
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Definition
| the cell body of a neuron, which contains the nucleus |
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Definition
| a branched, treelike structure attached to the soma of a neuron; receives information from the terminal buttons of other neurons |
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Definition
| a junction between the terminal button of an axon and the membrane of another neuron |
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Definition
| the long, thin, cylindrical structure that conveys information from the soma of a neuron to its terminal buttons |
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Definition
| a neuron with one axon and many dendrites attached to its soma |
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Definition
| a neuron with one axon and one dendrite attached to its soma |
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Term
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Definition
| a neuron with one axon attached to its soma; the axon divides, with one branch receiving sensory information and the other sending the information into the CNS |
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Definition
| the bud at the end of a branch of an axon; forms synapses with another neuron; sends info to that neuron |
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Term
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Definition
| a chemical that is released by a terminal button; has an excitatory or inhibitory effect on another neuron |
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Term
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Definition
| a structure consisting principally of lipid molecules that defines the outer boundaries of a cell and also constitutes many of the cell organelles |
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Term
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Definition
| the viscous, semiliquid substance contained in the interior of a cell |
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Term
| adenosine triphosphate (ATP) |
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Definition
| a molecule of prime importance to cellular energy metabolism; its breakdown liberates energy |
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Definition
| a structure in the central region of a cell, contains the chromosomes |
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Term
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Definition
| a strand of DNA, with associated proteins, found in the nucleus; carries genetic information |
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Term
| deoxyribonucleic acid (DNA) |
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Definition
| long, complex macromolecule consisting of two interconnected helical strands; along with associated proteins, strands of DNA constitute the chromosomes |
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Term
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Definition
| the functional unit of the chromosome, which directs synthesis of one or more proteins |
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Term
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Definition
| support structure formed of microtubules and other protein fibers that are linked to each other and form a cohesive mass that gives a cell its shape |
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Term
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Definition
| an active process by which substances are propelled along microtubules that run the length of the axon |
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Term
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Definition
| a long strand of bundles of protein filaments arranged around a hollow core; part of the cytoskeleton and involved in transporting substances from place to place within the cell |
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Term
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Definition
| the supporting cells of the central nervous system |
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Term
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Definition
| a glial cell that provides support for neurons of the CNS, provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid |
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Term
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Definition
| the process by which cells engulf and digest other cells or debris by cellular degeneration |
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Definition
| a type of glial cell in the CNS that forms myelin sheaths |
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Term
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Definition
| a sheath that surrounds axons and insulates them, preventing messages from spreading between adjacent axons |
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Term
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Definition
| a naked portion of a myelinated axon, between adjacent oligodendroglia or Schwann cells |
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Term
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Definition
| the smallest of glial cells; they act as phagocytes and protect the brain from invading microorganisms |
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Term
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Definition
| a cell in the peripheral nervous system that is wrapped around a myelinated axon, providing one segment of its myelin sheath |
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Definition
| a semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain's capillaries |
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Term
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Definition
| a region of the medulla where the blood-brain barrier is weak; poisons can be detected there and can initiate vomiting |
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Term
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Definition
| a conductive medium that can be used to apply electrical stimulation or to record electrical potentials |
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Term
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Definition
| the electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell |
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Term
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Definition
| a lab instrument that is capable of displaying a graph of voltage as a function of time on the face of a cathode ray tube |
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Definition
| the membrane potential of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potentials |
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Term
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Definition
| reduction of the membrane potential of a cell from its normal resting potential |
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Term
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Definition
| an increase in the membrane potential of a cell, relative to the normal resting potential |
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Term
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Definition
| the brief electrical impulse that provides the basis for conduction of information along an axon |
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Term
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Definition
| the value of the membrane potential that must be reached to produce an action potential |
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Term
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Definition
| movement of molecules from regions of high concentrations to regions of low concentrations |
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Term
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Definition
| an aqueous solution of a material that ionizes - namele, a soluble acid, base, or salt |
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Term
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Definition
| a charged molecule. Cations are positively charged and anions are negative |
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Definition
| the attractive force between atomic particles charged with opposite signs or the repulsive force between atomic particles charged with the same sign |
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Term
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Definition
| the fluid contained within cells |
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Term
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Definition
| body fluids located outside of cells |
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Term
| sodium-potassium transporter |
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Definition
| a protein found in the membrane of all cells that extrudes sodium ions from and transports potassium ions into the cell |
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Term
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Definition
| a specialized protein molecule that permits specific ions to enter or leave cells |
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Term
| voltage-dependent ion channel |
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Definition
| an ion channel that opens or closes according to the value of the membrane potential |
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Term
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Definition
| the principle that once an action potential is triggered in an axon, it is propagated, without decrement, to the end of the fiber |
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Term
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Definition
| the principle that variations in the intensity of a stimulus or other information being transmitted in an axon are represented by variations in the rate at which that axon fires |
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Term
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Definition
| conduction of action potentials by myelinated axons. The action potential appears to jump from one node of Ranvier to the next |
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Term
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Definition
| alterations in the membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse |
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Term
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Definition
| the location on a receptor protein to which a ligament binds |
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Term
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Definition
| a chemical that binds with the binding site of a receptor |
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Term
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Definition
| a small bud on the surface of a dendrite, with which a terminal button of another neuron forms a synapse |
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Term
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Definition
| the membrane of a terminal button that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released |
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Term
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Definition
| the cell membrane opposite the terminal button in a synapse; the membrane of the cell that receives the message |
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Term
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Definition
| the space between the presynaptic membrane and the postsynaptic membrane |
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Term
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Definition
| a small, hollow, beadlike structure found in terminal buttons; contains molecules of a neurotransmitter |
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Term
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Definition
| a region of the interior of the presynaptic membrane of a synapse to which the synaptic vesicles attach and release their neurotransmitter into the synaptic cleft |
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Term
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Definition
| a receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter |
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Term
| neurotransmitter-dependent ion channel |
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Definition
| an ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor |
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Term
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Definition
| a receptor molecule located on a neuron that responds to the neurotransmitter released by that neuron |
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Term
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Definition
| a receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of a neurotransmitter attaches to the binding site |
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Term
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Definition
| a receptor that contains a binding site for a neurotransmitter ; activates an enzyme that begins a series of events that opens an ion channel elsewhere in the cell's membrane when a molecule of the neurotransmitter attaches to the binding site |
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Term
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Definition
| a protein coupled to a metabotrophic receptor; conveys messages to other molecules when a ligand binds with and activates the receptor |
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Term
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Definition
| a chemical produced when a G protein activates an enzyme; carries a signal that results in the opening of the ion channel or causes other events to occur in the cell |
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Term
| excitatory postsynaptic potential (EPSP) |
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Definition
| an excitatory depolarization of the postsynaptic membrane of a synapse caused by the liberation of a transmitter by the terminal button |
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Term
| inhibitory postsynaptic potential (IPSP) |
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Definition
| an inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button |
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Term
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Definition
| the reentry of a neurotransmitter just liberated by a terminal button back through its membrane, thus terminating the postsynaptic potential |
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Term
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Definition
| the destruction of a neurotransmitter by an enzyme after its release - for example, the destruction of acetylcholine by acetylcholinesterase |
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Term
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Definition
| a neurotransmitter found in the brain, spinal cord, and parts of the peripheral nervous system; responsible for muscular contraction |
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Term
| acetylcholinesterase (AChE) |
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Definition
| the enzyme that destroys acetylcholine soon after it is liberated by the terminal buttons, thus terminating the postsynaptic potential |
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Term
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Definition
| the process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron |
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Term
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Definition
| the action of a presynaptic terminal button in an axoaxonic synapse; reduces the amount of neurotransmitters released by the postsynaptic terminal button |
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Term
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Definition
| the action of a presynaptic terminal button in an axoaxonic synapse; increases the amount of neurotransmitter released by the postsynaptic terminal button |
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Term
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Definition
| a natural secreted substance that acts like a neurotransmitter except that t is not restricted to the synaptic cleft but diffuses through the extracellular fluid |
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Term
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Definition
| a chain of amino acids joined together by peptide bonds. Most neuromodulators, and some hormones, consist of peptide molecules. |
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Term
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Definition
| a chemical substance that is released by an endocrine gland and that has effects on target cells in other organs |
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Term
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Definition
| a gland that liberates its secretions into the extracellular fluid around capillaries and into the bloodstream |
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Term
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Definition
| the type of cell that contains receptors for a particular hormone and is affected by that hormone |
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