5 Written Questions

1. Axon covered with a myelin sheath
2. Drug that attaches to the sodium channels of the membrane, preventing sodium ions from entering and thereby blocking action potentials
3. Electrical gradient across a membrane
4. Membrane potential that varies in magnitude and does not follow the all-or-none law
5. Time after the absolute refractory period, when potassium gates remain open wider than usual, requiring a stronger than usual stimulus to initiate an action potential

5 Matching Questions

1. Propagation of the action potential
2. Hyperpolarization
3. Absolute refractory period
4. Sodium-potassium pump
5. Action potential

1. a Rapid depolarization and slight reversal of the usual polarization caused by stimulation beyond the threshold
2. b Time immediately after an action potential, when the sodium gates close and the membrane cannot produce an action potential in response to stimulation of any intensity
3. c Mechanism that actively transports three sodium ions out of the cell while simultaneously drawing in two potassium ions
4. d Transmission of an action potential down an axon
5. e Increased polarization across a membrane

5 Multiple Choice Questions

1. Small neuron with no axon or a very short one
   1. Myelin
   2. Local neurons
   3. Local Anesthetic
   4. Polarization
2. Jumping of action potentials from one node to another by the flow of positive ions
   1. Action potential
   2. Resting potential
   3. Polarization
   4. Saltary conduction
3. Brief period following an action potential, when the cell resists the production of further action potentials
   1. Absolute refractory period
   2. Resting potential
   3. Refractory period
   4. Relative refractory period
4. Swelling of the soma, the point where the axon begins
   1. Myelin
   2. Local neurons
   3. Axon hillock
   4. Polarization
5. Principle stating that the size, amplitude, and velocity of the action potential are independent of the intensity of the stimulus that initiated it
   1. Action potential
   2. Axon hillock
   3. All-or-none law
   4. Local neurons

5 True/False Questions

1. Resting potential → Rapid depolarization and slight reversal of the usual polarization caused by stimulation beyond the threshold

   True        False

2. Selectively Permeable → Difference in positive and negative charges across a membrane

   True        False

3. Concentration gradient → Difference in positive and negative charges across a membrane

   True        False

4. Threshold of excitation → Level of depolarization at which a brief stimulation triggers a rapid, massive electrical change by the membrane

   True        False

5. Voltage-gated channels → Axon covered with a myelin sheath

   True        False