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

Monoclonal antibody, Monoclonal Antibody is an antibody with quite specifi...

Monoclonal Antibody is an antibody with quite specific and often unique binding specificity which is secreted by the biologically cloned line of plasmacytoma cells in the absence

Describe diversity of ion channel structure, Describe three mechanisms cell...

Describe three mechanisms cells use to produce diversity of ion channel structure and function.

Human eye, by our eyes we can see the beautiful world but is there anything...

by our eyes we can see the beautiful world but is there anything in our eyes which makes it beauiful??

Explain water - an essential but overlooked nutrient, Explain Water - An Es...

Explain Water - An Essential but Overlooked Nutrient? You may already know that the total body water (TBW) constitutes 50-60% of the body weight. A 70 kg 'standard male' contai

Define hexokinase, Hexokinase, that catalyzes the first irreversible step o...

Hexokinase, that catalyzes the first irreversible step of glycolysis, is inhibited by glucose 6-phosphate.   Thus  when  PFK  is  inhibited and  fructose  6-phosphate builds  up an

General preventive measures for animals, GENERAL PREVENTIVE MEASURES - ...

GENERAL PREVENTIVE MEASURES - 1.      Infected animal should be immediately isolated and looked after. 2.      The premises should be disinfected whenever there is an outbre

Can diseases be etiological factor for diabetes, Q. Can Diseases be etiolog...

Q. Can Diseases be etiological factor for diabetes? Diseases: In aging, a very important cause of diabetes could be an underlying disease. Diabetes occurs secondary lo some ot

Respiration, explain why expired air contain co2

explain why expired air contain co2

Major divisions of the chordate phylum, Q. What are the two major divisions...

Q. What are the two major divisions of the chordate phylum? Chordates are divided into vertebrates and protochordates (urochordates and cephalochordates). Q. What are the d

Explain the productivity of ecology, Explain the Productivity of ecology? ...

Explain the Productivity of ecology? When scientists study an ecosystem as a whole, they often examine the relationships between feeding, or trophic, levels. In order to do th

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