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

Show the explanation passes a chi square test, You work with petunias and y...

You work with petunias and you have identified a single gene that causes their flowers to either be all pigmented (solid), or streaked with white. Depending on the genotype of this

Name the alpha-islet cells of the pancreas, Person X is a healthy human who...

Person X is a healthy human who has volunteered to take experimental drug Y.  Person X has a normal dinner at 6 PM on April 1 and then does not eat for 12 hours.  At 5 PM on A

Tubercular meningitis , Tubercular Meningitis (TBM) Tubercular meningi...

Tubercular Meningitis (TBM) Tubercular meningitis is a serious complication of childhood tuberculosis. It usually occurs secondarily to primary infection with tuburculosi

List the benefits of exercises, List the benefits of exercises. Benefit...

List the benefits of exercises. Benefits of exercise are : - improves sugar control - decreases HbA1c level - decreases  blood pressure - decreases triglyceride lev

ANIMAL COMMUNICATION, what is the excitation threshold of a neuron?how does...

what is the excitation threshold of a neuron?how does this threshold relate to the all or nothing rule of neural transmission

Explain etiology and clinical feature of parkinson''s disease, Explain the ...

Explain the Etiology and Clinical Features of Parkinson's disease? The cause of Parkinson's is unknown. Genetic predisposition (in most cases the reason for the death of these

Brookes formula, Brooke's  Formula: a)  Fluid  requirement  b)  Es...

Brooke's  Formula: a)  Fluid  requirement  b)  Estimate the accurate/approximate weight of the patient  c)  First  24  hours  Colloids (blood, plasma, dextran) 0.5 ml

What is biomolecules?, A biomolecule is any molecule that is produced by a ...

A biomolecule is any molecule that is produced by a living organism, including large macromolecules like proteins, polysaccharides, lipids, and nucleic acids, as well as small mole

Define physical capacity tests for aerobic capacity, Define Physical Capaci...

Define Physical Capacity Tests for Aerobic capacity? Aerobic capacity has already been defined. Aerobic capacity is usually measured using a tread mill test in which the intens

Explain about cerebral hemispheres, How is it structurally explained that t...

How is it structurally explained that the motor activity of the left side of the body is controlled by the right cerebral hemisphere and the motor activity of the right side of the

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