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Flashcards in Q6 (Go over again) Deck (10):
1

Why is the diameter of the squid's giant axon so large?

Because it is unmyelinated, so this is to decrease the resistance and allow for greater longitudinal current.

2

In mammals what increases axonal speed of propagation without increasing fiber diameter?

Myelin

3

What type of currents flow from an advancing action potential and depolarize the membrane ahead to allow propagation?

Longitudinal currents

4

As axon diameter decreased, is more or less current necessary to stimulate it?

Less current

5

What is the classic preparation for myelinated axons in vertebrates?

Frog sciatic nerve

6

The myelinated regions of axons are called what?

Internodes

7

The unmyelinated regions of axons are called what?

Nodes of Ranvier

8

Ion channel densities are tenfold greater in what axonal regions?

The nodes between myelin regions

9

What pathological condition causes axons to become demyelinated in a patchy and unpredictable way?

Multiple sclerosis

10

A change in what is known to improve the prospects of impulse invasion of the demyelinated region of axons?

Temperature