9344861
Description
Flashcards by Lorann Kearney, updated more than 1 year ago
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Created by Lorann Kearney
over 7 years ago
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| Question | Answer |
| sensory neuron | neuron that detects changes in the external or internal environment and sends information about these changes to the central nervous system |
| motor neuron | neuron located within the central nervous system that controls the contraction of a muscle or the secretion of a gland |
| interneuron | neuron located within the nervous system |
| Central Nervous System (CNS) | the brain and spinal cord |
| Peripheral Nervous System (PNS) | The part of the nervous system outside the brain and spinal cord, including the nerves attached to the brain and spinal cord |
| soma | cell body of a neuron, which contains the nucleus |
| dendrite | a branched, treelike structure attached to the soma of a neuron that receives information from the terminal buttons of other neurons |
| synapse | junction between the terminal button of an axon and the membrane of another neuron |
| axon | the long, thin, cylindrical structure that conveys information from the soma of a neuron to its terminal buttons |
| multipolar neuron | a neuron with one axon and many dendrites attached to its soma |
| bipolar neuron | a neuron with one axon and one dendrite attached to its soma |
| unipolar neuron | 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 central nervous system |
| terminal button | the bud at the end of a branch of an axon; forms synapses with another neuron; sends information to that neuron |
| neurotransmitter | a chemical that is released by a terminal button; has a excitatory or inhibitory effect on another neuron |
| membrane | a structure consisting principally of lipid molecules that defines the outer boundaries of a cell and also constitutes many of the cell organelles |
| cytoplasm | the viscous, semiliquid substance contained in the interior of a cell |
| mitochondria | an organelle that is responsible for extracting energy for nutrients |
| adenosine triphosphate (ATP) | a molecule of prime importance to cellular energy metabolism; its breakdown liberates energy |
| nucleus | a structure in the central region of a cell, containing the chromosomes |
| chromosome | a strand of DNA, with associated proteins, found in the nucleus that carries genetic information |
| deoxyribonucleic acid (DNA) | a long, complex macromolecule consisting of two interconnected helical strands; along with associated proteins, strands of DNA constitute the chromosome |
| gene | the functional unit of the chromosome, which directs synthesis of one or more proteins |
| cytoskeleton | 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 |
| enzyme | a molecule that controls a chemical reaction, combining two substances or breaking a substance into two parts |
| axoplasmic transport | an active process by which substances are propelled along microtubules that run the length of the axon |
| microtubule | 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 |
| glia | the supporting cells of the central nervous system |
| astrocyte | a glial cell that provides support for neurons of the central nervous system, provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid |
| phagocytosis | the process by which cells engulf and digest other cells or debris caused by cellular degeneration |
| oligodendrocyte | a type of glial cell in the central nervous system that forms myelin cheaths |
| myelin sheath | a sheath that surrounds axons and insulates them, preventing messages from spreading between adjacent axons |
| mode of Ranvier | a naked portion of a myelinated axon, between adjacent oligodendroglia or Schwann cells |
| microglia | the smallest of glial cells which act as phagocytes and protect the brain from invading microorganisms |
| Schwann cell | a cell in the peripheral nervous system that is wrapped around a myelinated axon, providing one segment of its myelin sheath |
| blood-brain barrier | a semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain's capillaries |
| area postrema | a region of the medulla where the blood-brain barrier is weak; poisons can be detected there and can initiate vomiting |
| electrode | a conductive medium that can be used to apply electrical stimulation or to record electrical potentials |
| microelectrode | a very fine electrode, generally used to record activity of individual neurons |
| membrane potential | the electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell |
| oscilloscope | a laboratory instrument that is capable of displaying a graph of voltage as a function of time on the face of a cathode ray tube |
| resting potential | the membrane potential of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potentials; approximately -70mV in the giant squid axon |
| depolarization | reduction (towards zero) of the membrane potential of a cell from its normal resting potential |
| hyperpolarization | an increase in the membrane potential of a cell, relative to the normal resting potential |
| action potential | the brief electrical impulse that provides the basis for conduction of information along an axon |
| threshold of excitation | the value of the membrane potential that must be reached to produce an action potential |
| diffusion | movement of molecules from regions of high concentration to regions of low concentration |
| electrolyte | an aqueous solution of a material that ionizes - namely, a soluble acid, base, or salt |
| ion | a charged molecule that can be positively (cat-) or negatively (an-) charged |
| electrostatic pressure | the active force between atomic particles charged with opposite signs or the repulsive force between atomic particles charged with the same sign |
| intracellular fluid | the fluid contained within cells |
| extracellular fluid | body fluids located outside of cells |
| sodium-potassium transport | a protein found in the membrane of all cells that extrudes sodium ions from and transports potassium ions into the cell |
| ion channel | a specialized protein molecule that permits specific ions to enter or leave cells |
| voltage-dependent ion channel | an ion channel that opens or closes according to the value of the membrane potential |
| all-or-none law | the principle that once an action potential is triggered in an axon, it is propagated, without decrement, to the end of the fiber |
| rate law | 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 |
| saltatory conduction | conduction of action potentials by myelinated axons. the action potential appears to jump from one node of Ranvier to the next |
| postsynaptic potential | alterations in the membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse |
| binding site | the location on a receptor protein to which a ligand binds |
| ligand | a chemical that binds with the binding site of a receptor |
| dendritic spine | a small bud on the surface of a dendrite, with which a terminal button of another neuron forms a synapse |
| presynaptic membrane | the membrane of a terminal button that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released |
| postsynaptic membrane | the cell membrane opposite the terminal button in a synapse; the membrane of the cell that receives the message |
| synaptic cleft | the space between the presynaptic membrane and the postsynaptic membrane |
| synaptic vescile | a small, hollow, beadlike structure found in terminal buttons; contains molecules of a neurotransmitters |
| release zone | a region of the interior of the presynaptic membrane of a synapse to which synaptic vesciles attach and release their neurotransmitters into the synaptic cleft |
| postsynaptic receptor | a receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter |
| neurotransmitter-dependent ion channel | an ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor |
| ionotropic receptor | a receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site |
| metabotropic receptor | a receptor that contains a binding site for a neurotransmitter that 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 transmitter attaches to the binding site |
| G protein | a protein coupled to a metabotropic receptor that conveys messages to other molecules when a ligand binds with and activates the receptor |
| second messenger | 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 |
| excitatory postsynaptic potention (EPSP) | an excitatory depolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button |
| inhibitory postsynaptic potential (IPSP) | an inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button |
| reuptake | the reentry of a neurotransmitter just liberated by a terminal button back through its membrane, thus terminating the postsynaptic potential |
| enzymatic deactivation | the destruction of a neurotransmitter by an enzyme after its release (Example: the destruction of acetylcholine by acetylcholinesterase |
| acetylcholine (ACh) | a neurotransmitter found in the brain, spinal cord, and parts of the peripheral nervous system that is responsible for muscular contraction |
| acetylcholinestrase (AChE) | The enzyme that destroys acetylcholine soon after it is liberated by the terminal buttons, thus terminating the postsynaptic potential |
| neural integration | the process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron |
| autoreceptor | a receptor molecule located on a neuron that responds to the neurotransmitter released by that neuron |
| presynaptic inhibition | the action of a presynaptic terminal button in an axoaxonic synapse that reduces the amount of neurotransmitter released by the postsynaptic terminal button |
| presynaptic facilitation | the action of a presynaptic terminal button in an axoaxonic synapse that increases the amount of neurotransmitter released by the postsynaptic terminal button |
| neuromodulator | a naturally secreted substance that acts like a neurotransmitter except that it is not restricted to the synaptic cleft but diffuses through the extracellular fluid |
| peptide | a chain of amino acids joined together by peptide bonds. Most neuromodulators, and some hormones, consist of these molecules |
| hormone | a chemical substance that is released by an endocrine gland and that has effects on target cells in other organs |
| endocrine gland | a gland that liberates its secretions into the extracellular fluid around capillaries and hence into the bloodstream |
| target cells | the type of cell that contains receptors for a particular hormone and is affected by the hormone |
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