NervSystemNotes

NervSystemNotes - Biology 100 Fall 2005 Notes on the...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology 100, Fall 2005 (11/27/05) Notes on the Nervous System (see Chap 45) The Resting Potential : Inside of axon is negative (approx. -70 mV ) when there are no nerve impulses occurring Special Terms: Depolarization = more positive (upward from the resting level) Hyperpolarization = more negative (downward from the resting level) The Action Potential = Nerve Impulse: Ion Gradients ---------> Electrical Signal (nerve impulse) -- Na + conc. high on outside -- K + conc. high on inside --> Gradients maintained by action of Na-K pump (which uses ATP) Signal: -70 mV --> +30 mV --> -70 mV ==> 100 mV amplitude How the Action Potential "works": "stimulus" --> depolarization --> Na + gates open --> Na + enters axon --> more depol. --> more Na + entry --> more depol. --> etc., etc., etc. --> inside positive (+30 mV) Na + gates close automatically ; meanwhile, K + gates open --> K + flows out --> resting potential restored (-70 mV) 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
For every action potential: Na flows into the axon, after which K flows out of the axon. -
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/01/2008 for the course BIOL 100 taught by Professor Staff during the Spring '07 term at UMBC.

Page1 / 3

NervSystemNotes - Biology 100 Fall 2005 Notes on the...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online