Conduction of impulse, Biology



  • The impulse moves along the axon as local effect by altering the permeability of neighbouring Na+  channels and affecting every next channels in succession moving the effect ahead from axon hilllock to the axon terminal.
  • This is called stepwise or local circuit theory of transmission & is comparatively a slower conduction, generally found in invertebrates.


  • As axon is insulated the impulse, generated at axon hilock can effect the Na+  channel only at the node of Ranvier where the axolemma is exposed, which means Na+  can cross the membrane only at these sites.
  • This effect moves quickly from one node to another i.e. saltatory transmission.
  • Velocity of transmission of impulse is a to       

                     - degree of myelination

                     - temperature

                     - diameter of axon, it is 1500 m in sea squid while in vertebrats only 25-35 m

  • The average valocity of conduction in frog is about 20-25 m/sec. while in mammals 100-200 m/sec.
  • The fastest in some nerves of human beings is upto 532 kmph.

648_nerve impulse.png

Posted Date: 10/3/2012 2:25:34 AM | Location : United States

Related Discussions:- Conduction of impulse, Assignment Help, Ask Question on Conduction of impulse, Get Answer, Expert's Help, Conduction of impulse Discussions

Write discussion on Conduction of impulse
Your posts are moderated
Related Questions
What is meant by terminal electron acceptor? Give examples of e acceptors for aerobic and anaerobic respiration.

Cutaneous respiration in frogs and toads

Explain Feeding Schedule in Infancy? 1) Milk feed 5-6 times/day. Continue breast-feeding. Exclusive breast-feeding up to 6 months even during illness. Follow demand feeding.

Coo k in g loss and quality Yields and cooking losses of products are important as these determine acceptability and economics of products. Higher cooking losses increase th

Q. Why is the digestive system of these animals called incomplete? Incomplete digestive system is in that which the digestive cavity has only one opening.

Explain the Glycemic index in Chronic Diseases? In addition to serve as an aid in planning diets for diabetics, GI of diets has been linked to a number of chronic diseases. Sev

How does the inflammation mechanism work? When some tissue injury happens histamine and other vasoactive substances (known as mediators of inflammation) are released, they caus

What is Weaning from Mechanical Ventilation? It is crucial to get the timing just right as to when to discontinue mechanical ventilation and extubate. If too early, this might

This main protein component of connective tissue in mammals includes most of the organic matter of skin, bones, tendons, and teeth and occurs as fibrous inclusions in most other bo