Biological Physics: Energy, Information, Life

12.1. The problem of nerve impulses[[Student version, January 17, 2003]] 445 R=1/(gA) VNernst I=jqA ∆V=V 2 −V 1 (in) 1 2 (out) 2 ...

446 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] 3.The electrical potential is the same at either end of a wi ...

12.1. The problem of nerve impulses[[Student version, January 17, 2003]] 447 horizontal wires imply (by point (3) above) that al ...

448 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] last Example. Summarizing, Equation 12.3 is an approximation ...

12.1. The problem of nerve impulses[[Student version, January 17, 2003]] 449 entire axon must balance, while those in the immedi ...

450 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] dx Ix(x) a V(x) IIxx((xx+d+dxx)) V(x+dx) Ir(x)(x) (V=0outsid ...

12.1. The problem of nerve impulses[[Student version, January 17, 2003]] 451 the interior fluid (representing the axon’s cytopla ...

452 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] Tounderstand the minus sign, note that ifV increases as we m ...

12.2. Simplified mechanism of the action potential[[Student version, January 17, 2003]] 453 d. Interpretation Our model axon is ...

454 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] θ ∆h a b Figure 12.5:(Schematic.) Mechanical analogy to the ...

12.2. Simplified mechanism of the action potential[[Student version, January 17, 2003]] 455 force. Let the total retarding force ...

456 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] The following subsections will explore a simplified, one-sho ...

12.2. Simplified mechanism of the action potential[[Student version, January 17, 2003]] 457 Figure 12.6: (Photomicrograph; oscil ...

458 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] seawater, 100%cNa + 0 50%cNa + 0 33%cNa 0 + 1 2 -80 -40 0 40 ...

12.2. Simplified mechanism of the action potential[[Student version, January 17, 2003]] 459 ̃V( t)= V (0 ,t ) V^0 ̃v(t 2 ) t t A ...

460 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] in the membrane’s permeabilities to various ions. Net curren ...

12.2. Simplified mechanism of the action potential[[Student version, January 17, 2003]] 461 Note that Equation 12.17 states that ...

462 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] +10mV v v ab sodium conductivity gNa + membrane current flux ...

12.2. Simplified mechanism of the action potential[[Student version, January 17, 2003]] 463 In short, our model displays thresho ...

464 Chapter 12. Nerve impulses[[Student version, January 17, 2003]] 5. 2.5 0 2.5 5. 7.5 10. 0.2 0.6 1. x =0 wrongθ x =6 λaxon x ...