Neuroscience Quiz: Action Potentials and Glial Cells

Multiple Choice Questions

• Question 1: Initiation of the action potential typically occurs at the axon initial segment of the neuron.
• Question 2: A true statement about an animal's nervous system is that neurons form highly discrete lines of communication.
• Question 3: For a hormone to trigger a specific cellular response, the cell must have receptor proteins that are specific to the hormone.
• Question 4: The startle response in cockroaches involves sensory neuron activation by vibrations, then synapses ultimately exciting the spinal cord.

Additional Questions

• Question 5: Peripheral nervous system glial cells include Schwann cells.
• Question 6: Glial cells act as intermediaries facilitating metabolic support for neurons.
• Question 7: Membrane potential relies on the separation of positive and negative charges.
• Question 8: Membrane capacitance is related to the membrane's ability to store electrical charge.
• Question 9: At the membrane, depolarization is occurring.
• Question 10: In the lower panel, the difference between the dashed and solid lines represents the difference in capacitive properties of the membrane.
• Question 11: In the figure, the graded potential is shown.
• Question 12: The difference between the middle and lower panels is due to the membrane voltage being farther from the current pulse.
• Question 13: Properties in the figure can be measured in neurons, pacemaker cells, and muscle cells.
• Question 14: The variable that does not contribute to passive electrical properties of a cell is resting membrane current.
• Question 15: Membrane potential results from ion concentration differences across the cell membrane.
• Question 16: In the center of the figure, the cell would have a slight negative charge.
• Question 17: The Nernst Equation does not include capacitance.
• Question 18: Differences in ion concentrations are due to both active transport and passive diffusion.
• Question 19: Depolarization is caused by a decrease in the membrane concentration of anions.
• Question 20: The true statement regarding ions in animal cells is that K+ leaks out slowly due to its smaller electrochemical gradient.
• Question 21: The Goldman equation considers membrane permeability when determining ion contributions to a membrane potential.
• Question 22: Voltage-gated Na+ channels are primarily responsible for the all-or-nothing nature (all-or-none property) of an action potential.
• Question 23: Sodium permeability is highest at point I in the provided figure.
• Question 24: Voltage-gated Na+ channels are inactivated at points III and IV.
• Question 25: Voltage-gated potassium channels are responsible for the undershoot.
• Question 26: When the membrane is clamped at -100mV, voltage-gated channels do not open/behave as shown in the diagram.
• Question 27: Three pulses are needed to reach the threshold.
• Question 28: Simultaneous stimulus 3 and 6 would not generally produce an action potential.
• Question 29: Increasing the current pulse's length and strength increases the frequency of action potentials.
• Question 30: In a resting axon at resting membrane potential, the voltage-gated Na+ channels are inactivated, while K+ channels are open, and voltage-gated Ca2+ channels remain closed.
• Question 31: When the action potential is falling (repolarization), the K+ leak channels are open, the voltage-gated Na+ channels are inactivated.
• Question 32: Voltage clamp was used to collect the data in the bottom panel.
• Question 33: I in the figure corresponds to outward current flow through voltage-gated Na+ channels.
• Question 34: The channels at II stay open longer because channels at I become inactivated, and only close due to membrane voltage.
• Question 35: The technique in the figure used is voltage clamp.
• Question 36: The treatment on the left side is hyperpolarization, and on the right side hyperpolarization (in Na+ free seawater).
• Question 37: If the neuron is in TEA, the inward ionic current would be absent.
• Question 38: Apart from the initial shift, no other current is produced during voltage clamp at 0mV.
• Question 39: Channels changing primary structures in response to membrane depolarization is not false.
• Question 40: A primary characteristic shared by spiking and nonspiking neurons is neurotransmitter secretion based on membrane potential changes.
• Question 41: Nonspiking neurons function despite graded signal degradation through short signals and a high concentration of channels in the axon for signal propagation.
• Question 42: Cardiac action potential is shown in the figure.
• Question 43: The plateau in the figure is due to voltage-gated calcium channels remaining open.
• Question 44: K+ permeability is at its lowest very close to the peak of the membrane potential.
• Question 45: Inactivation of voltage-gated sodium channels is responsible for the absolute refractory period.
• Question 46: The statement that is false regarding local circuits is that anions migrate into the membrane's interior.
• Question 47: Inactivation of Na+ channels prevents bidirectional propagation of action potentials.
• Question 48: Conduction velocity in axons is proportionally related to the square root of the axon diameter.
• Question 49: Myelination is the most significant variable regarding conduction velocity.
• Question 50: Myelination increases action potential velocity by increasing membrane resistance and decreasing capacitance, enabling "jumps" across the myelinated regions.
• Question 1: Neurons convert electrical signals into chemical signals at the presynaptic terminal.
• Question 2: Afferent neurons transmit sensory signals to the CNS.

Test your knowledge on the fundamental concepts of neuroscience, including action potentials, the peripheral nervous system, and the role of glial cells. This quiz covers key topics such as neuronal communication and membrane potentials. Perfect for students studying biology or neuroscience.