NSC 4352 1st Edition 1 Capacitance is The ability of a membrane to hold change Final Exam Study Guide 2 The length constant lambda are true for the following All of the above 3 Propagation of the action potential around the axon depends on or is influenced by All of the above 4 How can K channels select Na ions Both Na K ions must shed their hydration shell when passing through the channel 5 If a cell has a large length constant lambda this means that The likelihood that two distant synapses will fire an action potential is increased 6 The spatial summation of 2 graded potentials at the dendrites of a neuron is influenced by which of the following length constant 7 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 ions 8 The ion selectivity of voltage gated sodium channel is conferred by P Region 9 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 in response to 10 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 gradient 12 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 capacitance 14 All of the following describe the structure of voltage gated sodium channels except Inactivation is achieved by binding of 2 Na ions 15 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 con 16 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 except 18 All of the following is true for currents flowing through individual voltage gated k channels except they are specialized by bapta 19 Miniature endplate potentials MEPPs All of the above 20 If you microinject Ca2 in presynaptic terminal you will Get transmitter release in the absence of AP 21 Connexin 36 is A gap junction protein 22 What is the name of the calcium sensor that sits on the synaptic vesicle Synaptotagmin 23 MEPPs are an indicator of vesicular qualtal release of chemical synapses because They are a fraction of EPPs 24 Exocytosis of neurotransmitter quantal release requires the following step to occur interaction of Synaptotagmin neurexin 25 The active zone at the neuromuscular junction is characterized by High density of voltage gated calcium channels 26 All small molecule transmitters classical neurotransmitters are Synthesized in the synaptic terminal and are taken back into the terminal via transporters 27 Synaptins are a family of proteins that keep vesicles tethered in the reserve pool 28 The release of neurotransmitters into the synaptic cleft is called Exocytosis 29 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 influx 30 The sodium potassium pump and various ion exchangers are examples of Active transporters 31 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 depolarized 2 Multiple sclerosis is degeneration of myelin 3 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 102 4 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 effect on the AP decrease the amplitude of the action potential 6 the resting membrane potential is not identical to the equilibrium potential or potassium because the other ions that go through depolarize it 7 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 above 9 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 correct 11 action potential is an all or non event is graded all or none 12 the nucleus of the cell contains the nucleolus and chromosomes 13 couldn t hear question 14 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 above 15 couldn t hear question 16 a typical synapse in the cortex consists of all of the above 17 the role of microglia couldn t hear answer 18 The nerdst equation all of the above 19 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 correct 20 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 hillock 21 the shape and time course of the action potential is determine by a couldn t hear what he said 22 the voltage clamp experiment action potential is characterized by a inward current that depends on sodium ions followed by an outward current that depends on potassium ions 23 the goldman equation is