Conduction in myelinated axons, Biology

Assignment Help:

Conduction in Myelinated Axons

The myelin sheath provides insulation for the axon preventing movements of Na+ and K+ through the membrane. Therefore, if this myelin sheath was continuous no action potential would be generated. Fortunately, gaps or nodes of Ranvier occur in the myelin. Since the cable properties of axon can conduct depolarisations over very short distance (1-2 mm), the nodes of Ranvier must be close together (actually they are 1 mm apart). Studies have shown that the Na+ channels are concentrated at the nodes and absent from the regions between two nodes. Action potential therefore occurs only at the nodes of Ranvier and seems to leap from node to node. This is called saltatory conduction. The spread of depolarisation between the nodes is very fast and fewer action potentials are needed. Therefore, the rate of conduction is much faster than in unmyelinated fibres.

This peculiar structure and mode of conduction in myelinated fibres is responsible for the fast conduction of impulses in motor nerves of vertebrates even though the nerves are very thin. The greatest advantage of myelinated fibres comes from their smaller size and so a highly complex nervous system with high conduction velocities can occur without occupying too much of space.


Related Discussions:- Conduction in myelinated axons

When aflatoxigenic molds can occur, Q. When Aflatoxigenic molds can occur? ...

Q. When Aflatoxigenic molds can occur? Occurrence: Aflatoxigenic molds can occur in warmer parts of the world and aflatoxicosis maybe produced in a wide range of tropical and s

Cartilage occur in a joint and what it its function, Where does cartilage o...

Where does cartilage occur in a joint and what it its function? Cartilage might be found covering the surface of bones where they meet in a movable joint. Cartilage decreases f

Explain defensive proteins, Explain Defensive Proteins These proteins p...

Explain Defensive Proteins These proteins protect against diseases. Antibodies are the example of defensive proteins. These  combat bacteria and viruses. Also, immunoglobulins,

How can heart be affect, How can Heart be affect Heart may be affected ...

How can Heart be affect Heart may be affected in two ways. One of the complications of diabetes is autonomic dysfunction which may disturb rhythm of heart beat and may lead to

Bioinformatics is important, Why do you think that bioinformatics is import...

Why do you think that bioinformatics is important?         Ans) Today, we can use computers to access much more biological data than still before. You can learn a lot by analysi

How respiratory pigments act, Q. How respiratory pigments act? Respirat...

Q. How respiratory pigments act? Respiratory pigments are oxygen-carrying molecules present in the blood. When the oxygen concentration is high for instance, in the pulmonary a

Explain about the importance of vitamins, Explain about the Importance of V...

Explain about the Importance of Vitamins? Vitamins are the organic substances that act as coenzyme and/or regulator of metabolic processes. There are 13 known vitamins, most of

Explain the dark adaptation of vitamin a, Explain the Dark Adaptation of Vi...

Explain the Dark Adaptation of Vitamin A? In the early stages of VAD, the individual cannot see objects in dim light. This' phenomenon is used as a criterion for assessment in

Why nutrition is important for health, Why Nutrition is important for healt...

Why Nutrition is important for health Nutrition is one of the basic components of  life. It is an essential part of health care. You already know that good nutrition  is essent

What are the hormones produced by the testicles, What are the hormones prod...

What are the hormones produced by the testicles and the ovaries? The testicles make androgenic hormones, the major of them being testosterone. The ovaries make estrogen and pro

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