PHYS 1010 Lecture 6: Nerve Signals Maintaining Homeostasis
22 Feb 2019
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Document Summary
There are no pores on area with myelin sheath. Pores are only located in strategically placed, spaces in-between known as nodes of ranvier. Separated just right so signal jumps from one node to another. This allows signals to travel 10-100 times faster. This would cause a lot of damage to your skin: reflexes are often involuntary and often unconscious. The movement of sodium ions into the nerve cell causes the depolarization of the membrane. This signals an action potential in that area, but in order for this impulse to be conducted along the axon, it must move from the point of depolarization to adjacent regions. It begins with polarization, depolarization and then repolarization and then the cycle continues and goes back and forth. Threshold levels and the all-or-none response: nerve cells respond to changes in ph, pressure and to specific chemicals, threshold level: the minimum level of a stimulus required to produce a response.
