Neurites, Biology

Assignment Help:

NEURITES -

The processes of neurons are called neurites. These are of two types: dendrites or dendrons and an axon or axis cylinder or neuraxon.

(a)      Dendrites (Dendrons). These are usually shorter, tapering and much branched processes. They may be one to several. The dendrites contain neurofibrils, neurotubules and Nissl's granules. They conduct nerve impulse to- wards the cell body and are called afferent processes (= receiving processes). It's fine branches are telodendria.

(b)      Axon. Axon is a single, usually very long process of uniform thickness. The part of cyton from where the axon arises is called axon hillock.

  • Most sensitive part of neuron is axon hillock.
  • The axon contains neurofibrils and neurotubules but does not have Nissl's granules, Golgi complex, ribosomes, pigment granules, fat globules, etc.
  • In the absence of Nissl's granules, the axon depends on the cell body for the supply of proteins.
  • The cell membrane of the axon is called axolemma and its cytoplasm is known as axoplasm.
  • The axon ends in a group of branches, the terminal arborizations (= axon terminals or telodendria).
  • When terminal arborizations of the axon meet the dendrites of another neuron to form a synapse they form synaptic knobs (= end plates).
  • The synaptic knobs contain mitochondria and secretory vesicles. On muscle fibres and gland cells, the terminal arborizations end as motor end plates.
  • Each axon may also possess lateral or branches called collateral fibres which are usually much finer than the main axonal process.
  • The axon conducts nerve impulses away from the cell body, therefore, called an efferent process.
  • synapse is a site of junction between terminal arborizations of axon of one neuron and the dendrites of
  • another neuron.

2126_structure of nerve fibre or neuron.png

  • Each neuron receives an impulse through its dendrites and passes it on to the next neuron through synapse.
  • A fresh impulse is set up in the dendrites at the synapse with the help of chemicals called neurotransmitters, such as acetylcholine produced by the secretory vesicles of the synaptic knobs.
  • Acetylcholine is the first neurotransmitter to be discovered.

Related Discussions:- Neurites

Explain highly active antiretroviral therapy, Highly active antiretroviral ...

Highly active antiretroviral therapy (HAART) - The treatment of HIV infection requires combination therapy known as highly active antiretroviral therapy (HAART) along with inte

Calculate the electric potential, The three charges in the are at the verti...

The three charges in the are at the vertices of an isosceles triangle. Let q = 7.00 nC and calculate the electric potential at the midpoint of the base.

Define essential parts of photocolorimeter - monochromators, Define Essenti...

Define Essential Parts of Photocolorimeter - Monochromators? This is a means of selecting a sufficiently narrow waveband. Early colorimeters used glass filters that transmitted

Can you explain the anoxia, Q. What is the anoxia? Anoxia is a situatio...

Q. What is the anoxia? Anoxia is a situation in which there is no available oxygen in the cell without oxygen the respiratory chain stops there is no ATP production the cell do

Explain endoskeleton in detail, Explain Endoskeleton in detail. Support...

Explain Endoskeleton in detail. Supporting structures of the skeleton surrounded by the body tissues. As a consequence, there is living tissue on all sides of endoskeletal stru

Phylum protozoa, what arr the economic importance of phylum protozoa

what arr the economic importance of phylum protozoa

What is congenital heart operations and interventions, What is Congenital H...

What is Congenital Heart Operations And Interventions Aftercare of the children who have undergone cardiac procedures and surgeries is as important, and in some occasions, more

Explain the concerns of genetically modified (gm) foods, Normal 0 ...

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

Protostomes, differences between acoelomate,coelomate and pseudocoelomate

differences between acoelomate,coelomate and pseudocoelomate

Which is utilized by other reactions, The breakdown of ATP releases energy,...

The breakdown of ATP releases energy, which is utilized by other reactions that require energy. Identify other examples where inventions have utilized a similar principle, where en

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