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 nutrition monitoring and evaluation, Nutrition Monitoring and Evalu...

Nutrition Monitoring and Evaluation Monitoring and evaluation is an essential step in the nutritional care process and  is very important too. Monitoring specifically refers to

Define the activation of an agonist during movement, Explain the relationsh...

Explain the relationship between an agonist muscle and its antagonist as it relates to positional control, functional movement and neuromuscular activation. For example, how the th

Describe the structure of chromatin and chromosomes, Describe how the struc...

Describe how the structure of chromatin and chromosomes facilitates the following functions: a) DNA packaging. b) Regulation of gene expression.  c) Replication at the

Role of government in health care provision, Role of Government in Health C...

Role of Government in Health Care Provision The government intervenes in the health sector with a general view of improving the health status of the people. In general governm

Central carbons participate in the peptide bond, Q. Do the -H groups bound ...

Q. Do the -H groups bound to the central carbons participate in the peptide bond? The central carbons themselves, the -R groups and the hydrogen attached to the central carbons

Illustrate the nature of the stimulus, Q. What is the nature of the stimulu...

Q. What is the nature of the stimulus received and transmitted by the neurons? Neurons transmit and receive chemical stimuli through neurotransmitters released in the synapses.

What is polyembryony, What is polyembryony? Polyembryony is the phenome...

What is polyembryony? Polyembryony is the phenomenon in which a single embryo in its initial embryonic stage separates itself forming many new individuals of the similar sex an

Difference between the concepts of food chain and food web, What is the dif...

What is the difference between the concepts of food chain and food web? The chain theory is a theoretical model to study the energy flux in ecosystems. In fact, in an ecosystem

Fertilization in earthworm, In earthworms, when the ovaries mature, the cli...

In earthworms, when the ovaries mature, the clitellum secretes a viscous substance in the form of a girdle. This girdle hardens in to a cocoon around the clitellum. The ova are dis

What is the ph inside the stomach, What is the pH inside the stomach? Why i...

What is the pH inside the stomach? Why is there a need to keep that pH level? How is it maintained? Which are the cells that produce that pH? The normal pH of the gastric juice

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