Nodes of Ranvier

• What is the appearance of Nodes of Ranvier on an axon?

  They appear as breaks in the myelin sheath
• What are the steps of saltatory conduction?

  1. Signal depolarizes at a node
  2. Electrical charge spreads under myelin sheath
  3. Signal jumps to next node
  4. Depolarization occurs at new node
  5. Process repeats along axon
• What occurs at the new node during saltatory conduction?

  Depolarization occurs at the new node
• How does the action potential travel in saltatory conduction?

  It jumps between nodes of Ranvier
• What is the function of Nodes of Ranvier?

  Allow rapid electrical signal transmission
• What are Nodes of Ranvier?

  Gaps in the myelin sheath
• What is the function of the myelin sheath?

  It insulates axons for efficient signal transmission
• How do Nodes of Ranvier contribute to nerve signal transmission?

  They facilitate rapid signal jumps along the axon
• What do Nodes of Ranvier create along the axon?

  Gaps of exposed axon membrane
• What is the structure of the myelin sheath around axons?

  • Formed by Schwann cells
  • Regularly spaced gaps (Nodes of Ranvier)
  • Creates segments along the axon
• What is saltatory conduction?

  It is the jumping of signals between nodes
• What are the features of myelinated and demyelinated axons?

  • Myelinated Axon:
  • Fast signal speed
  • Regular nodes
  • Complete myelin coverage
  • Jumps between nodes for signal propagation

  
  

  • Demyelinated Axon:
  • Slow signal speed
  • Irregular or absent nodes
  • Partial or no myelin coverage
  • Continuous spread of signals
• What happens to signal transmission in multiple sclerosis?

  Demyelination disrupts signal transmission, slowing impulses
• What is the process called that allows signals to travel rapidly along myelinated axons?

  Saltatory conduction
• Where are Nodes of Ranvier located on an axon?

  At regular intervals along the axon
• What do the gaps in the myelin sheath allow for?

  Rapid electrical signal transmission
• How are Nodes of Ranvier positioned in relation to Schwann cells?

  • Positioned between Schwann cells
  • Form the myelin sheath
  • Create a punctuated pattern along the axon
• What is the role of Schwann cells in relation to the myelin sheath?

  They form the myelin sheath around axons
• How do the myelin sheath and nodes of Ranvier work together?

  They enable efficient signal transmission in axons
• How does the structure of the myelin sheath affect nerve signal speed?

  It increases speed due to insulation and gaps
• What happens to the electrical charge during saltatory conduction?

  It spreads under the myelin sheath