Conduction of impulse, Biology

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.

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
T he effects of unlimited population growth are as follows: 1.         Increase in unemployment. 2.          Low per capita income. 3.         Low living standard

Which is the kind of gamete (for a given trait) produced by a dominant homozygous individual? What is genotypical proportion of these gametes? And what about the recessive homozygo

Nuclear transfer method: Nuclear transfer will extend the range of species in which gene targeting will be possible and thereby provide better models to test treatments for human

Cutaneous respiration in earthworm. The respiration performed by the skin is called cutaneous respiration  In earthworm skin is the only organ of respiration. The skin

Which term is used to describe the process whereby a catheter is inserted into an individual's heart, a radio-opaque medium is injected & x-ray images are made. Procedure is use

Q. How Alkaline cleaning compounds works? Carbonates, bicarbonates, hydroxides of various metals are called alkaline compounds. Alkaline cleaning compounds have a pH between

Q. On average what is the life duration of the red blood cells? Where are they destroyed? What is the destination of the heme groups after the destruction of hemoglobin molecules?

A 70-kg adult person could meet all of his/her entire energy needs for one day by consuming 3 moles of glucose (540 g)- not a highly recommended diet!. Each molecule of glucose gen

Differance between pulsus bigerniny or trigeminy and presence of bruit ? Pulsus bigerniny or trigeminy: After every 2nd or 3rd beat respectively there will be a longer inter