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

Explain the alpha-helix and the beta-sheet protein, Normal 0 fa...

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

Explain minerals requirement during thyphoid, Explain Minerals requirement ...

Explain Minerals requirement during thyphoid Minerals:   Loss of electrolytes and water is observed due to diarrhoea. Thus liberalizing on sodium intake  through salty soups,

What is the non-paralytic squnit, Concomitant or Non-Paralytic Squnit ...

Concomitant or Non-Paralytic Squnit This type of squint usually occurs when there is an obstacle in the sensory pathway of binocular reflex such as refractive errors, opacities

Circulatory systems in animals, Circulatory Systems in Animals In anim...

Circulatory Systems in Animals In animals that have efficient circulatory systems and readily permeable vascular skins, gas exchange occurs through the integument. Thus we fin

Determine the biocompatibility of the material, Determine the Biocompatibil...

Determine the Biocompatibility of the material It is a vital factor as we have discussed in detail in the preceeding part of this unit. The nature of the material and its surf

Explain three main steps for a good study of genetic tree, What are the thr...

What are the three main steps for a good study of a genetic family tree? Step 1: to determine whether the studied phenotypical form has a dominant or recessive pattern. Step

Why do male and female gametes diffrent from each other, Q. Concerning thei...

Q. Concerning their size and basic morphology how and why do the male and the female gametes differentiate from each other? The female gametes are big cells full of vitellus (n

Population growth curve, Increase in population size is known as population...

Increase in population size is known as population growth. It depends upon number of persons added to the population and number of persons lost from the population. Addition in pop

Determine uses of soybean protein, Determine uses of Soybean protein? S...

Determine uses of Soybean protein? Soybean protein concentrates have been used as stabilized dispersions in milk- like beverages and simulated dairy products, such as sour crea

#title.how can help me solve this problem?, i have a question on how to pro...

i have a question on how to proceed the fomular of delete the gene on the human body.

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