Electrical conduction in nerves

20 Electrical conduction in nerves





Questions



image How are electrical impulses carried in a nerve cell?

image How is re-entrant excitation prevented in a region of nerve that has just fired an action potential?

image What factors govern the conduction velocity of nerves?

image What is saltatory conduction in nerve fibres? Why does it occur? How does saltatory conduction influence conduction velocity in nerve fibres?


Impulse propagation


Nerve impulses propagate via local currents that are induced within the nerve after firing of an action potential. During an action potential, the active region of membrane becomes more positively charged inside compared with adjacent regions and more negative outside compared with adjacent regions. Induced local currents raise adjacent resting regions of the nerve membrane to threshold for firing of an action potential, thereby propagating the electrical signal along the nerve membrane (Fig. 3.20.1).


image

Fig. 3.20.1 Directional propagating of an action potential in a nerve.

Related posts:

  1. DNA and gene transcription
  2. Ion transporters in cellular physiology
  3. The extracellular matrix
  4. Proteins and protein function

Stay updated, free articles. Join our Telegram channel
Tags:
Jun 18, 2016 | Posted by in BIOCHEMISTRY | Comments Off on Electrical conduction in nerves

Full access? Get Clinical Tree
Get Clinical Tree app for offline access