Giant nerve fibres, Biology

Assignment Help:

Giant Nerve Fibres

We now know that giant nerve fibres take place in the central nervous system of many polychaetes, oligochaetes, insects cephalopod etc. They are broader and longer as compared to the other, ordinary nerve fibres which are about 2 μm or so only in diameter. In the squid, they might attain a diameter of 700 μm or even more. Their size makes them ideal material for electrophysiological studies, like recording electrodes can be inserted inside the axons and action potentials measured. They are of immense benefit to the animal because, with the increase in diameter of the axon, resistance for propagation of action potential is decreased, while velocity of propagation is increased. They conduct for longer distances with fewer or no synapses that also further facilitate conduction. On the whole they are pre-eminently suited for rapid conduction. These Fibres are included in escape reactions of the animal. The squid for instance is rapidly propelled in water by expelling the water within the mantle cavity by fast and simultaneous contraction of the muscles of the mantle innervated by the giant fibres by using the principle of jet propulsion. The animal can escape from its enemies through this method within a fraction of a second.


Related Discussions:- Giant nerve fibres

Explain nutrient cycling and their processes, Explain Nutrient Cycling and ...

Explain Nutrient Cycling and their processes? Two major processes are common to all ecosystems: nutrient cycling and the flow of energy. These two functions are carried out by

Biological fixation - nitrogen fixation, Biological fixation - Nitrogen Fix...

Biological fixation - Nitrogen Fixation Approximately 63% of all nitrogen fixed is through biological fixation. Nitrogen fixing organisms are primarily prokaryotes; bacteria a

Regression of primitive streak, Regression of Primitive Streak As...

Regression of Primitive Streak As the inward migration of cells by the primitive streak ends progressively along its anterior to posterior regions the streak slowly regre

Explain the future challenges for neuroscience, Explain the Future challeng...

Explain the Future challenges for Neuroscience? When the analysis of single cells and even networks has progressed very nicely, there still remain many significant questions. A

Psychiatric emergencies, Psychiatric Emergmcy: Psychiatric  Emergmcy i...

Psychiatric Emergmcy: Psychiatric  Emergmcy is  the treatment of disorders of mood, thought and behavior in  an emergency  setting. Psychiatric emergencies are conditions in w

Different types of gas exchange in animals, Q What are the different kinds ...

Q What are the different kinds of gas exchange that occur in animals? In beings from the kingdom Animalia the gas exchange may occur either by diffusion, cutaneous respiration,

What is osteoblast, What is osteoblast The osteoblast is the key for th...

What is osteoblast The osteoblast is the key for the development of new bone. It is essential that a large number of osteoblasts accumulate on the implant surface(contact osteo

Vaccines for gas infections, In developing countries because of poor compli...

In developing countries because of poor compliance, poverty, ignorance, primary and secondary prevention strategies are difficult to implement properly. Also in western countries (

Why are euglenas involved in polemics, Q. Why are euglenas involved in pole...

Q. Why are euglenas involved in polemics related to their taxonomic classification? Euglenas are involved in taxonomic polemics because they tend to be classified sometimes as

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