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

Nucleus, NUCLEUS First described and christened by Robert brown 1831, a...

NUCLEUS First described and christened by Robert brown 1831, a nucleus is the largest and most important organelle of eukaryotic cells. It is membrane bound and generally locat

Explain fish actomyosin, Fish actomyosin Fish actomyosin has been found...

Fish actomyosin Fish actomyosin has been found to be quite labile and easily changed during processing and storage. During frozen storage, the actomyosin becomes progressively

Explain diseases of pericardium, Q. Explain Diseases of pericardium? Pe...

Q. Explain Diseases of pericardium? Pericardium is the sac covering the heart. Pericardium consists of two layers-the visceral pericardium (epicardium) and the parietal pericar

Species diversity - synthetic characters, Species Diversity - Synthetic Cha...

Species Diversity - Synthetic Characters It is one of the most important and basic characteristics of a community. There are various ways of measuring species diversity the si

Is there chloroplasts in cyanobacteria, Q. Is there chloroplasts in cyanoba...

Q. Is there chloroplasts in cyanobacteria? In cyanobacteria there is no chloroplast and the chlorophyll layers are dispersed in cytosol.

Gangrenous dermatitis (necrotic dermatitis), G a ngrenous dermatitis (nec...

G a ngrenous dermatitis (necrotic dermatitis) A bacterial condition in chickens caused by spores of Clostridium septicum , sometimes that of Cl. novyi / Cl. edematiens a

Ribonucleases and deoxyribonucleases, Ribonucleases  and  deoxyribonuclea...

Ribonucleases  and  deoxyribonucleases These enzymes  are  responsible  for  the degradation of  dietary  nucleic acids. Ribonucleases  and  deoxyribonucleases secreted by  the

Define anaerobic exercise or energy system, Define Anaerobic Exercise or En...

Define Anaerobic Exercise or Energy System? Thus, exercises which are done for short bursts of time lasting only for few seconds (less than 120 sec) use only anaerobic system o

Feeding on food masses, Normal 0 false false false EN-I...

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

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