Knowledge test

     1. A neuron consists of:

• • Dendrites, nucleus, axon, synaptic buttons
  • Dendrites and axon
  • nucleus and axon
  • Dendrites, nucleus, axon, myelin sheath

2. Which of the following statements regarding action potential is incorrect?

• • corresponds to a hyperpolarisation
  • is triggered only in response to a stimulus
  • starts only if a certain threshold is exceeded
  • causes polarity reversal

3. The propagation process is triggered by:

• • the presence of voltage-gated channels for Na+
  • the existence of a particular refractory period
  • the repeated recurrence of the triggering stimulus
  • the existence of potential even in the sections at rest
    

4. The resting potential is due to the presence of:

• • Na+ ions outside the cell and K+ inside the cell
  • Na+ ions inside the cell and K+ outside the cell
  • Na+ ions inside the cell and Cl- outside the cell
  • K+ ions outside the cell and Cl- ions inside the cell

5. Which of the following statements about the cable model is incorrect?

• • The axon can be schematized by a circuit containing two resistors and a capacitance in series
  • The axon can be schematized by a succession of meshes with resistors and capacitors
  • The inner part of the axon has a very high resistance
  • The membrane itself forms a capacitor in parallel with a resistor

8. Short answer: What value does resting potential have?

9. Open Answer: How does the action potential propagate along the axon?
   

10. Open Answer: How does the stimulus potential vary at a certain point as a function of time? Provide a qualitative description

11. Match each question with the correct answer:

• • What measures the space constant?
  • What does the time constant measure?
  • What does the space constant depend on?
  • What does the time constant depend on?

10. Short answer: What does the speed of nerve impulse propagation in unmyelinated neurons depend on according to the cable model?