neuroscience 2

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neuroscience 2
2013-10-02 22:03:22

neuroscience exam 1 deck 1
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  1. Axon Hillock
    a small conical elevation on the soma of a neuron that does not contain Nissl substance; the site of the generation of action potentials in a neuron.
  2. Cytoskeleton
    cytoplasmic component of the neuron that is the main determinant of its shape
  3. Microfilaments
    formed by two strands of polymerized globular actin monomers. play an important role in the motility of growth cones during development
  4. Nissl Substance or Bodies
    material consisting of RNA granules (ribosomes)
  5. Astrocytes
    glial cell that supports neurons in the brain and regulates the chemical and extracellular environments
  6. Muller Cells
    modified astrocytes found in the retina
  7. Tanycytes
    specialized ependymal cells found in the floor of the third ventricle; their processes extend into the brain tissue, where they are juxtaposed to blood vessels and neurons. They are implicated in the transport of hormones from the cerebrospinal fluid to capillaries of the portal system and from hypothalamic neurons to the CSF
  8. Oligodendrocytes
    supporting cells responsible for myelination of axons in the central nervous system.
  9. Perineurium
    connective tissue sheath that encloses each bundle of nerve fibers
  10. Cation
    Positively charged ion
  11. Anion
    Negatively charged ions
  12. Carrier Protein
    • protein that transports a specific substance or group of substances through intracellular
    • compartments or in extracellular fluids (in the blood) or else across the cell membrane.
  13. Concentration Gradient
    difference in concentrations of a solute during transport; solute moves from high to low areas of concentration
  14. Passive Transport
    process by which substances are moved across the cell membrane without chemical energy
  15. Depolarization
    reduction in the negative charge inside a neuron
  16. Hyperpolarization
    increase in the negative charge inside a neuron
  17. ion channels
    channels that allow some ions to cross the membrane in the direction of their concentration gradients
  18. Ionotropic Receptor
    receptor in which four to five protein subunits are arranged in such a way that the recognition site for the neurotransmitter is part of the ion channel; a transmitter binds to its receptor and brings about a conformational change that results in the opening of the ion channel.
  19. Threshold Potential
    a membrane potential at the trigger zone at which action potentials become self-propagating
  20. gated channel
    allosteric protein that is mostly in the closed state at rest and opens in response to a stimulus
  21. Refractory Period
    time required for the sodium channel to revert from inactivated to resting state (de-inactivation) of the neuron
  22. gap junction
    is an area where two neurons are apposed to each other at an electrical synapse
  23. Connexon
    each hemichannel in a gap junction channel
  24. Synaptic cleft
    fluid filled gaps which separate the cells of the presynaptic terminal and postsynaptic neuron
  25. Graded potentials
    are brief local changes in membrane potential that occur in neuronal dendrites and cell bodies, but not axons
  26. Neuromuscular Junction
    the synapse of the axon terminal of a neuron with the motor end-plate.
  27. Axosomatic Synapse
    occurs when the postsynaptic membrane is on the cell body (soma) of another neuron
  28. Symmetric Synapse
    synaptic arrangement in which postsynaptic and presynaptic membranes are similar in thickness (inhibitory synapse)
  29. axoaxonic synapse
    occurs when the postsynaptic membrane is on the axon of another neuron
  30. End-Plate Potential
    • electrical potential generated at the muscle
    • end-plate; elicited by activation of nicotinic cholinergic receptors located at
    • the end-plate by acetylcholine
  31. Trigger Zone
    the site where action potentials are generated; the axon hillock is the trigger zone in neurons.
  32. Exocytosis
    process in which there is fusion of the neurotransmitter-containing vesicle with the presynaptic terminal membrane, resulting in an opening through which the neurotransmitter is released into the synaptic cleft.
  33. Clathrin
    protein involved in endocytosis; forms a basket-like lattice on the remnants of a fused vesicle giving the appearance of a coated pit
  34. Clear-Core synapses
    contain small-molecule neurotransmitters; found at fast synapses
  35. Propeptide
    pre-peptide from which the signal sequence of amino acids is removed
  36. Acetylcholine
    serves as a neurotransmitter at the terminals of preganglionic neurons in the sympathetic as well as parasympathetic ganglia, at the terminals of parasympathetic post-ganglionic neurons.
  37. Glutamate
    major excitatory amino acid neurotransmitter in the central nervous system synthesized from glutamine in presence of the enzyme glutaminase.
  38. Gamma aminobutyric Acid (GABA)
    small-molecule inhibitory neurotransmitter synthesized from glutamate by the enzyme, glutamic acid decarboxylase
  39. Glycine
    small-molecule, inhibitory neurotransmitter synthesized from serine
  40. Catecholamine
    chemical compound that contains a catechol (benzene ring with two adjacent hydroxyl groups [e.g., dopamine, norepinephrine, and epinephrine])
  41. Dopamine
    a small-molecule catecholamine neurotransmitter synthesized from tyrosine