Conduction of impulse, Biology

Assignment Help:

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


Related Discussions:- Conduction of impulse

Discuss about brain, Brain Brain is a part of central nervous system wh...

Brain Brain is a part of central nervous system which lies in the skull. Source: Sears and Windwood, Anatomy and Physiology for Nurses The different parts of the bra

Determination of the age of fossil, DETERMIN A TIO N OF THE AGE OF FOSSI...

DETERMIN A TIO N OF THE AGE OF FOSSIL - Radioactive clock (Boltwood -1907) - Half life of uranium is 4.5 billion years. This means half of total uranium disintegrates

Gametogenesis, The process of meiosis in animals is called gametogenesis .I...

The process of meiosis in animals is called gametogenesis .It takes place in the testis in male and ovary in female. Gametogenesis is divided into spermatogenesis (formation of

The identity and amounts of elements in the molecule, If the chemical formu...

If the chemical formula of a substance is C17 H 31 COOH, what can you tell about the identity and amounts of elements in the molecule? Can someone please explain me this?

Non insulin dependent diabetes mellitus, Q. Explain about Non Insulin Depen...

Q. Explain about Non Insulin Dependent Diabetes Mellitus? Overweight and obese adults are generally afflicted by this type of diabetes. The insulin produced by the pancreas is

How are lipids used as an energy source by the organism, How are lipids use...

How are lipids used as an energy source by the organism? Carbohydrates are the major energy source for aerobic cell respiration. In the absence or deficiency of such substances

Define locust bean gum, Locust Bean Gum Locust bean gum (also called Ca...

Locust Bean Gum Locust bean gum (also called Carob bean gum) is extracted from the seed (kernels) of the carob tree (Ceratonia siliqua). Structurally, locust bean gum is compos

Behavioural adjustments, Behavioural Adjustments When faced with a su...

Behavioural Adjustments When faced with a sudden temperature change, most animals make behavioural responses that enable them to avoid extreme or lethal conditions. Among the

Progressive senescence - senescence, Progressive senescence - Senescence ...

Progressive senescence - Senescence This is the third category of senescence. Here also the leaves are shed but it is gradual senescence of leaves up the stem. For example, th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd