BPK 105 Lecture Notes - Lecture 2: Paravertebral Ganglia, Central Nervous System, Vasodilation

• School: Simon Fraser University
• Department: Biomedical Physio & Kines
• Course: BPK 105
• Professor: Ryan Dill

Document Summary

Module 4 do questions 6, and 11: explain how a myelinated axon can conduct a signal faster than an unmyelinated axon of similar diameter. Use and define appropriate terminology in your explanation. Myelinated axons are axons that are wrapped by specialized layers called myelin sheaths. Myelin acts as an insulator that stops ion movement through the cell membrane. The nodes of ranvier are gaps or spaces in the myelin sheath that are placed between schwann cells. The nodes of ranvier allow for ion movement. Axons with myelin sheaths makes the generation of action potentials down the axons faster and more effective. Unmyelinated axons lack myelin sheaths, making the generation of action potentials slower. Therefore, myelinated axons conduct a faster for action potentials than an unmyelinated axon of a similar diameter. This is because action potentials conduct by unmyelinated axons are triggered by local currents in neighboring parts of the cell membrane.