nervous system

3 Pages
Unlock Document

Peter Normark

The Nervous System 02/06/13 The nervous system has to deal effectively with information in 'real time' how does it do this? Break the problem down: 1. body detects stimulus (light, sound, touch, chemical, temperature, etc.) 2. sensory neuron translates this to something a cell would understand (a chemical/electrical signal) 3. sends signal to Central Nervous System (CNS) 4. interneurons are used to filter, magnify, interpret, or ignore signal 5. CNS directs this modified signal through motor neurons to muscle cells, to endocrine cells (to make hormones), etc. Signal is one way. At axon terminus, it jumps to next cell How does it work? Axon membrane at rest has a negative membrane potential (-70) FACT: diff. [ion] either side; more anions (-) inside Voltmeter used to measure difference in charge between inside/outside of cell to determine membrane potential dif. is maintained by Na+/K pump – for every three Na+ that leave cell, 5 K enter cell Fact: Membrane resting potential = -70 mV Neuron membrane setup: + -voltage-gated Na channel with 2 gates --voltage-gated K channel Fact: Na gate opens when membrane potential > -50 mV Def: graded potential anywhere below -50 mV (& not at resting potential) Fact: K gate opens when memb. pot. > +30 to +40 mV (approx.) =action potential membrane repolarizes when K gates open Starts when (enough) Na gates
More Less

Related notes for BIOLOGY 152

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.