Abstract
1. Based on the equation derived recently by myself on the relation betweenan active length x, and the resting length, y, which can be activated by x, theroles of membrane resistance and safety factor being played for conduction, were examined.2. The ratio of resting to active membrane resistance, rm/r'm, or the ratioof length constant of resting to active membranes, k/k', was found to play animportant role, together with the safety factor, f, for local excitation, for realizingthe all-or-nothing conduction. Generally, f decreases with increase ofthe ratio. The value of f for infinitely large ratio is unity. It seems verylikely that the necessary condition is satisfied with ample reserve in the squidgiant axon.3. Conduction velocity increases with rm until it attains maximum at a certainrm. The safety factor, f, decreases with rm and attains a certain definitevalue at the critical rm. This value decreases in inverse proportion to (1-e-x/k'), and attains e2 at x/k'=∞. The theoretical value for the squid giant axon isjust about e2, while a rough estimate of the actual value is7-8 or eventuallylarger than 10. The significances were discussed.4. The smaller the resistance r'm the larger is the conduction velocity andthe smaller the minimal active length, L, required for starting an impulse. 5. It was concluded that large rm and small r'm co-operate intimately withf for enhancing the “safety of conduction” in generalized sense.
