Myelinated fibre, Biology

Assignment Help:

Myelinated fibre

Axon is a relatively long process (also quite often referred to as nerve fibre) and can be considered as functionally specialised for conduction of excitation over considerable distances. In vertebrates the axons of high velocity neurons are covered by insulating sheaths of lipid containing myelin. This myelin is made up of special glial cells -the Schwann cells. The myelin covering is not continuous. There are tiny uninsulated gaps between adjacent Schwann cells. These are the-nodes of Ranvier. The myelin covering and nodes of Ranvier help accelerate the speed of conduction of impulses by a mechanism which we will discuss later. The terminal part of the axon branches, terminating into small ramifications whose tips form end knobs which synaptically contact with other nerve cells. In the end knobs are present characteristic structures called synaptic vesicles which contain and store chemical substances called neurotransmitters.

349_Myelinated fibre.png

Figure: Myelinated fibre

The diversity in neuron form, however so much that is there can be many variations from the generalized description given above. For example, the nerve cells called amacrine cells found in retina contain processes without a demonstrable axon.


Related Discussions:- Myelinated fibre

Timber, introduction,types,uses and characteristics of a good timber?

introduction,types,uses and characteristics of a good timber?

Explain spoilage of cereals and cereal products, Q. Explain Spoilage of Cer...

Q. Explain Spoilage of Cereals and Cereal Products? Cereals are the main source of energy to human beings. There are several varieties of cereals, of which wheat and rice are t

Exploitation of forests, Exploitation of Forests Exploitation of our f...

Exploitation of Forests Exploitation of our forests for commercial purposes and for food and fodder cannot be stopped completely because of symbiotic relationship between fore

Health insurance and its interaction with medical market, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Determine the solubility of micronutrient cations, Determine the solubility...

Determine the solubility of micronutrient cations The solubility of micronutrient cations is at a maximum at low pH values. As the pH increases the ions of these elements first

What are the main components of the cytoskeleton, The cytoskeleton is a net...

The cytoskeleton is a network of very little tubules and filaments spread throughout the cytoplasm of eukaryotic cells. It is made of microtubules, microfilaments and intermediate

Determine effective half life and value of effective decay, 1. By direct me...

1. By direct measurement of the activity of the thyroid gland in several patients who had received 131 I for diagnostic purposes, it was observed that the biological elimination h

Determine the term - vascular disorders, Determine the term - Vascular diso...

Determine the term - Vascular disorders Normal central nervous system functioning can be affected by a number of vascular problems, because blood-vessel disease or damage can g

Human respiratory system - larynx, LARYN X - Study of larynx is kno...

LARYN X - Study of larynx is known as Laryngeology. In man it is more prominent than woman known as Adam's apple. It is sound producing organ. At its base trachea presen

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