Phys Ch8 Exam2

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Phys Ch8 Exam2
2011-10-17 22:16:05
Phys Ch8 Exam2

Phys Ch8 Exam2
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  1. 3 main components of synapse are presynaptic ____, postsynaptic ___, and the ____ which is where the 2 meet
    neuron, cell, synapic cleft
  2. Chemical msngrs of neurons
  3. 5 steps of transmitting signal across a synapse
    • 1. Action potential comes down axon
    • 2. Action potential opens voltage-gated Ca+ channels
    • 3. Ca+ enters presynaptic cell & triggers exocytosis of NT
    • 4. NT diffused across synapse & binds to receptor on postsynaptic cell
    • 5. Response in cell
  4. What causes synapic delay?
    Time it takes for Ca+ to come into neuron & for NT to be released (NOT time that diffusion of NT across synaptic cleft takes, which is instantaneous)
  5. 3 types chemical receptors at synapses
    • Channel-linked receptors
    • G protein-linked receptors (couple to either ion chanel or 2nd msgr system)
  6. Change in mem potential of the postynaptic cell in rsponse to receptor-NT binding, can be inhibitory or excitatory
    Postynaptic Potential (PSP)
  7. Excitatory postsynaptic potential (EPSP) causes ____ (increase or decrease) in amt of pos chrgs in cell due to ___ ions ____ the cell, ie it causes _____
    increase; lots Na+ entering; depolarization

    (membrane potential is less negative)
  8. Inhibitory postsynaptic potential (IPSP) causes ____ ions to ____ cell , which causes ____ (increase or decrease) in amt of pos chrgs in cell; ie it causes ____
    K+ or Cl-; leave; decrease; hyperpolarization

    (cell gets more negative)
  9. Chlorine has a higher concentration ___ of cell when it's not at equilibrium, and if a NT opens Cl- channel, causing _____, the inside of the cell becomes more ____ as Cl- travels ___ cell
    outside of cell, hyperpolarization, neg, into
  10. Potassium channel is closed by a
    neurotransmitter, so closing that channel
    causes positive charges to stay in the cell, which causes a less negative membrane potential, which means it is ____
  11. When Cl- is at equilibrium a NT opening a Cl- channel doesn't change mem potential b/c Cl- will stabilize the membrane potential by going out or in based on the mvmt of the other ion in or out (counteracts it)
    Membrane potential stabilization
  12. One axon branches out ot many
  13. Multiple axons acting on one neuron
  14. The summing of input from various synapses at the axon hillock of the postsynaptic neuron to determine whether the neuron will generate action potentials
    Neural integration
  15. Temporal summation vs spatial summation
    • temporal: take info from one synapse through time (ie back to back) to reach threshold
    • spatial: info taken from multiple synapses at the same time to reach threshold
  16. When modulating neuron stimulates or inhibits activity (amt of NT released) of presynaptic neuron which causes effect on postsynaptic neuron or not
    + 2 types
    • Presynaptic modulation
    • Presynaptic facilitation
    • Presynaptic inhibition
  17. Diff b/w axoaxonic, axodendritic, axosomatic synapses as far as what they affect
    • Axoaxonic: Excite or inhibit a synapse
    • Axodendritic & axosomatic: Excite or inhibit postynaptic neuron
  18. Most NTs are synthesized in cytosol of ___ ___, packaged into ___ ___, and then ___
    axon terminal, secretory vesicles, excreted by exocytosis
  19. Most abundant NT in PNS but is also everywhere else
  20. Synapse which utilizes acetylcholine
    Cholinergic synapse
  21. Types of cholinergic receptors
    • Nicotinic: channel-linked (only can open); skeletal muscle
    • Muscarinic: G-protein linked
  22. 3 types of biogenic amines which are derived from AAs
    • Catecholamines: dopamine, norepinephrine, epinephrine
    • Serotonin
    • Histamine
  23. Receptors which are for epinephrine & norepinephrine only
    Adrenergic receptors
  24. Type of adrenergic receptors which prefer norepinephrine to bind
    Alpha 1, Alpha 2, Beta 1
  25. Type of adrenergic receptors which prefer epinephrine to bind
    Beta 2