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

Define issues that are covered by nutrition economics, Define issues that a...

Define issues that are covered by nutrition economics? The issues that are covered by nutrition economics include: 1. Quantities of food commodities and their development in

How dissimilar is the gametogenesis in women and in men, Concerning events ...

Concerning events during the periods of life how dissimilar is the gametogenesis in women and in men? The formation of spermatogonia in men takes place during the embryonic per

Determine the signs and symptoms of bulimia, Determine the Signs and Sympto...

Determine the Signs and Symptoms of Bulimia? 1. Binges, minimum twice a week for three months 2. Purging a Menstrual irregularities 3. Swollen glands Frequent fluct

Explain the rapport building, Q. Explain the Rapport Building? Maintain...

Q. Explain the Rapport Building? Maintaining good relationship with the client is very important in counselling. This will help you to gain trust, confidence of the client and

Residual soils-types of soil, Residual Soils Residual soils are formed ...

Residual Soils Residual soils are formed at the same site where the weathering of the parent rock has taken place or soils formed in situ from the underlying rocks. These are a

Define primary motor cortex corticospinal interneuron a, Define Primary mot...

Define Primary motor cortex corticospinal interneuron A Primary motor cortex (M1) corticospinal interneuron A that produces action potentials during movements of the big toe of

Show the structure of the adult fern, Q. What is the structure of the adult...

Q. What is the structure of the adult fern within which cells undergoing meiosis can be found? In these plants meiosis takes place within structures known as sorus (plural, sor

Monkeey Opsin Evolution, Why does having three color receptors (a.k.a. opsi...

Why does having three color receptors (a.k.a. opsins) lead to a more complex color perception than just two?

Define structural elements - biological functions of protein, Define Struct...

Define Structural Elements - Biological Functions of Proteins? Structural proteins are fibrous proteins. The well known of the fibrous proteins are possibly the keratins, which

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