5 Written questions
5 Matching questions
- What advantage does having a myelin sheath give to a nerve fiber?
- What is an EPSP and a IPSP? Are these graded potentials, action potentials, or can they be both?
- Define excitability. What kinds of cells possess excitability?
- Do CNS nerve fibers generally regenerate?
- Describe two conditions that allow maintenance of the resting membrane potential. How are concentration gradients involved?
- a Not really.
- b Means that action potential doesn't have to travel down the entire axon, just jumps from node to node.
- c EPSP - Excitatory Post Synaptic Potential; potential of the cell to reach threshold again after it has been through a cycle.
IPSP - Inhibitory Post Synaptic Potential; Hyperpolarize on purpose to prevent a response to every stimulus.
- d Able to receive impulse from action potentials
- e The fact that the cell membrane is relatively negative and they are charged ions inside and outside the cell.
Concentration gradients involved because K+ ions are inside, Na+ ions are outside. Keep polarity of cell in check.
5 Multiple choice questions
- In order to get back to polarization, they have to pump in 3 Na out, 2 K in
- Depolarization - Potential difference becomes smaller or less polar. If extracellular concentration of K+ increases, there is less gradient between inside and outside.
Hyperpolarization - Potential difference becomes greater or more polar. If extracellular concentration of K+ decreases, steeper gradient between inside and outside
- In CNS, it doesn't heal.
In PNS, if mylineation cells are still in tact, they will reform a path for the neuron to grow.
Schwann Cells or Oligodendricites
- IPSP, Inhibitory Post Synaptic Potential.
5 True/False questions
Is the sodium-potassium pump and active or passive process? → Unipolar
What are gated channel? There different gated channels, which channels are regulated by neurotransmitters? → Mylination
Axons are classified into 3 groups according to the relationship between diameter, myelination and propagation speed: define Type A, B and C fibers. → Type A - large-diameter, myelinated. Conduct at 15-120 m/s. Motor neurons supplying skeletal and most sensory neurons
Type B - medium-diameter, lightly myelinated. Conduct at 3-15 m/s. Part of ANS
Type C - small-diameter, unmyelinated. Conduct at 2 m/s or less. Part of ANS
What gives peripheral nerves their white appearance? → Only allows certain things through.
What is salutatory conduction of an action potential? Does it occur in all nerve fibers? How does diameter of a nerve fiber affect speed of conduction? → ...