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

Radiography, R a d i o g r a p h y: ...

R a d i o g r a p h y: Radiograph or X-ray remains the most well-known and primary diagnostic tool of all the imaging modalities. It works b

What is a stream, What is a stream? A stream is a incessant series of by...

What is a stream? A stream is a incessant series of bytes that flow into or out of your program. Input and output from devices like the mouse, , disk, keyboard, screen, modem, a

Explain uses of modified starches in food, Uses of modified starches in foo...

Uses of modified starches in food and confectionery industries Visit a grocery shop and look out for products such as the instant desserts, jelly beans, salad dressings, tomato

Explain the concept of dressing, Explain the concpet of Dressing Dressi...

Explain the concpet of Dressing Dressing: Means medicine wound covering; a bandage or other sterile covering is put on a wound to protect it from infection or further damage.

Compare between mummers of dna vs monomers of rna, Name few polymers in the...

Name few polymers in the eukoratic cell? Name the mummers that make up the DNA? Compare and contrast between mummers of DNA VS monomers of RNA?

Do primary amines can act as bases, Primary amines can act as bases; they c...

Primary amines can act as bases; they can- Select one: a. Absorb a proton to become R-NH2+2 b. Release a proton to become R-NH2+ c. Absorb a proton to become R-NH3+

Photosynthesis, photosynthesis moderates global warming, briefly explain th...

photosynthesis moderates global warming, briefly explain this statement

New Technology, What is the best microscope to get a detailed view of the p...

What is the best microscope to get a detailed view of the parts inside of a preserved plant cell

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