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

Origin, What group did reproduction via sexual exchange of genetic informat...

What group did reproduction via sexual exchange of genetic information originate in?

Define about the listing plane, Define about the Listing Plane Listing ...

Define about the Listing Plane Listing proposed that only horizontal movements  of  the  eye  are performed around a vertical axis  in  the equatorial plane and vertical moveme

What are the gibberellins, What are the gibberellins? And where are they pr...

What are the gibberellins? And where are they produced? The Gibberellins are plant hormones that stimulate plant growth, fruit formation (also parthenocarpy) and the germinatio

What is sporocyst. specify., What is Sporocyst? Specify. A stage in the...

What is Sporocyst? Specify. A stage in the life cycle of trematode flukes. Sporocyst develops from the mericidium found in intermediate host. Every sporocyst contains the germ

Tissue, what is the location of connective tissues in our body

what is the location of connective tissues in our body

What is the likely function of the snf gene, In yeast, a new mutation calle...

In yeast, a new mutation called suc was recently discovered.  The suc mutant cannot use sucrose as a source of carbon, and will not grow if the culture medium contains only sucrose

Which are the organs of the excretory system, Which are the organs of the e...

Which are the organs of the excretory system? The excretory system is produced of kidneys (two), ureters (two), bladder and urethra. The Excretory System - Image Diversity:

Economic importance of wild life, ECONOMI C IMPORTANCE OF WILD LIFE  - ...

ECONOMI C IMPORTANCE OF WILD LIFE  - (i) Plants - Produce food. Provide Timber, paper, gums, drugs, pigments, fibres, rubber, oils, condiments & fuel. Release O

What is the molecular composition of hemoglobin, What is the molecular comp...

What is the molecular composition of hemoglobin? Does the functionality of hemoglobin as a protein depend upon its tertiary or upon its quaternary structure? Hemoglobin is a mo

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