NSC 4352 1st Edition Final Exam Study Guide1) Capacitance is? • The ability of a membrane to hold change.2) The length constant (lambda) are true for the following:• All of the above3) Propagation of the action potential around the axon depends on, or is influenced by?• All of the above4) How can K+ channels select Na+ ions?• Both Na+ & K+ ions must shed their hydration shell when passing through the channel5) If a cell has a large length constant (lambda), this means that• The likelihood that two distant synapses will fire an action potential is increased6) The spatial summation of 2 graded potentials at the dendrites of a neuron is influenced by which of the following?• length constant7) In the context of the cable theory (the passive electron of the cell), the term resistance • is the measure of the permeability of the membrane for ions8) The ion selectivity of voltage gated sodium channel is conferred by,• P Region9) Imagine that you have 2 neurons that receive the identical amount of synaptic inputs. 1 of the neurons has a higher input resistance than the other…• the neurons with the higher input resistance will show a larger voltage change inresponse to10) The myelin sheath around axons• Decreases the electrical capacitance of a neuron. Acts as insulator.11) The role of sodium/potassium pump is to• Transport sodium out of the cell against their concentration gradient12) Why does the action potential travel mostly down the axon, towards the axon terminals, and only to a much lower extent back into the soma and dendrite?• The density of Na+ channels is much higher in the axon than the dendrite. In addition,the Na+ channels are inactivated during the refractory period which greatly diminishes the spread of……13) The myelin sheath of Oligodendrocytes speeds up action potential propagation along the axon by?• Increasing membrane resistance and decreasing membrane capacitance14) All of the following describe the structure of voltage gated sodium channels except• Inactivation is achieved by binding of 2 Na+ ions15) Gap Junctions:• allows for electrical coupling between cells, are a means to establish and spread network oscillations, exists between glia cells, are established by specialized proteins called con16) Which of the following statements about is false? Na/K ATPase• Produces an inward current that determines the threshold of the action potential.17) The active zone is• A region in the presynaptic where AP occurs and high density of voltage-gated Ca2+ channelsAll of the following is true for currents flowing through individual voltage gated k+ channels except18) All of the following is true for currents flowing through individual voltage gated k+ channels except• they are specialized by bapta19) Miniature endplate potentials (MEPPs)• All of the above20) If you microinject Ca2+ in presynaptic terminal, you will• Get transmitter release in the absence of AP21) Connexin 36 is• A gap junction protein22) What is the name of the calcium sensor that sits on the synaptic vesicle?• Synaptotagmin23) MEPPs are an indicator of vesicular (qualtal) release of chemical synapses because• They are a fraction of EPPs24) Exocytosis of neurotransmitter (quantal release) requires the following step to occur• interaction of Synaptotagmin + neurexin25) The active zone at the neuromuscular junction is characterized by?• High density of voltage-gated calcium channels26) All small molecule transmitters (classical neurotransmitters) are• Synthesized in the synaptic terminal and are taken back into the terminal via transporters27) Synaptins are a family of proteins that:• keep vesicles tethered in the reserve pool28) The release of neurotransmitters into the synaptic cleft is called?• Exocytosis29) What did show __________ & Reed show when they blocked potassium channels with 4AP,they showed u get more neurotransmitter release, but why? • Prolong action potentials and more Ca2+ influx30) The sodium potassium pump and various ion exchangers are examples of?• Active transporters31) Name one factor that can change length constant (lambda)• Lambda = square root of (rm/ri+r0), membrane resistance. 1) suppose you’re recording a neuron’s resting membrane potential, if you add potassium to the outside of the neuron, what would happen to the resting membrane potential? - the membrane potential will become depolarized2) Multiple sclerosis is: - degeneration of myelin3) consider a cell in which the membrane potential is -76 and the equilibrium potential of potassium is -88, how can you make potassium move into the cell?-hyperpolarize to -1024) Hodgkin and Huxley were able to show that the rising phase of the action potential is due to:- the permeability of the sodium coming in-5) A drug that reduces the number of sodium channels that are available would have what effecton the AP?- decrease the amplitude of the action potential6) the resting membrane potential is not identical to the equilibrium potential or potassium because:-the other ions that go through depolarize it7) if the membrane potential is voltage clamped, the reversal potential of a given ion, which of the following statements is true:-8) which of the following statements about the length constant lambda is true:-all of the above9) which of the following statements best describes the state of the channels in the membrane just after the action potential?-10) astrocytes:-b and c are correct11) action potential is an all or non event, is graded:- all or none12) the nucleus of the cell contains:- the nucleolus and chromosomes 13) couldn’t hear question14) the sodium potassium pump:maintains the concentration gradient of sodium and potassium,, requires energy to transport ions across the concentration gradient, transports 3 sodium out, 2 potassium in- all of the above15) couldn’t hear question16) a typical synapse in the cortex consists of: - all of the above17) the role of microglia:- couldn’t hear answer18) The nerdst equation:-all of the above19) you record from a squid giant axon in which the reversal potential for potassium is at -92, you hyper polarize the membrane to -110, what will happen?-d - none of the above is correct20) cells receive and integrate many synaptic inputs, eventually an action potential may be initiated from some of these connections, the site of initiation of the action potential is:- axon hillock21) the shape