CONDUCTION OF IMPULSE -

IN NON-MYELINATED AXONS -

• 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.

IN MYELINATED AXON -

• 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.

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

Ask an Expert

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

Write your message here..

Related Questions

What is the phase of the menstrual cycle, In general what is the phase of t... In general what is the phase of the menstrual cycle when copulation may lead to fecundation? Although this is not a rule, to be effective fecundation in general must happen wit

Nested brackets as a cladogram, using either nested brackets as a cladogram... using either nested brackets as a cladogram, what are the hierarchical relationships among the followingtaxa:raniates, amniotes, mammals, actinopterygians, chondrichthyes, aves, ve

02, what is the effect of insuline in body ? what is the effect of insuline in body ?

The effect of gravity on roots, The effect of gravity on roots Cut vari... The effect of gravity on roots Cut various pieces of blotting paper about 8 cm square. Place these among two squares of glass. Place several radish or mustard seeds among the b

How to evaluate blanching efficiency, How to evaluate blanching efficiency?... How to evaluate blanching efficiency? Finally, let us learn how to evaluate blanching efficiency? Normally, two of the more heat resistant plant enzymes, namely peroxidase and

Promoters - transgenic animals, Promoters The promoter region contains ... Promoters The promoter region contains the DNA sequences that allow the formation of the transcription initiation complex that give the specificity of expression. Promoters are

Define gonads and reproductive system, Define Gonads and Reproductive Syste... Define Gonads and Reproductive System? With aging, there is decrease in pituitary hormone secretion causing decrease in gonadal hormone production, which causes number of chang

Different stages involved in feeding patient - peptic ulcer, Q. Different s... Q. Different stages involved in feeding patient - peptic ulcer? Stage I: It is characterized by haematemesis (vomiting of blood which may be derived from mouth, stomach, oesoph

Define deficiency and toxicity of vitamin d, Define Deficiency and Toxicity... Define Deficiency and Toxicity of Vitamin D? Infants constitute a population at-risk for vitamin D deficiency because of relatively large vitamin D needs brought about by their

What do you mean by varices, Q. What are varices? Why are they more common ... Q. What are varices? Why are they more common in the inferior limbs? Varix means abnormal enlargement of veins and the Varices occur when excessive pressure against the normal