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

Anatomic factors in patient selection for mitral valvuloplas, Q. Anatomic F...

Q. Anatomic Factors in Patient Selection for Mitral Valvuloplasty ? The ideal patient is young, has pliable non calcified mitral leaflets, and mild subvalvular disease. TEE may

Explain the procedure estimation of the amount of bacteria, Explain the Pro...

Explain the Procedure Estimation of the Amount of Bacteria? Now carry out the exercise following the steps enumerated herewith. 1. Prepare ten fold dilutions of E. coli cult

How you show that yeast acts on sugar, Normal 0 false false ...

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

Explain about the effect of nutrient and drug interaction, Explain about th...

Explain about the Effect of Nutrient and Drug Interaction? Medicines can treat and cure many health problems. Nevertheless, do you recall your doctor advising or recommending c

Pets, Pets, Medical Research and Zoos - Wildlife Animals and plants ar...

Pets, Medical Research and Zoos - Wildlife Animals and plants are gathered throughout the world for zoos, private collectors, pet shops and researchers in biology and medicine

Water - properties and functions, W A TER Occurence Water is ...

W A TER Occurence Water is the most abundant substance, covering 70% of earth's surface. It constitutes 60-90% of living cells.              5-6% in tooth e

Diversity2, using examples of invertebrate phyla illustrate how the increas...

using examples of invertebrate phyla illustrate how the increase in complexity is reflected by their nervous system?

Biological species concept, Q. Biological species concept? A biological...

Q. Biological species concept? A biological species as defined by Ernst Mayr are "groups of actually or potentially interbreeding natural populations which are reproductively

How pathologic conditions causing the underweight, How Pathologic Condition...

How Pathologic Conditions causing the underweight? Illness can affect weight status in a number of ways. For example, fevers and infections increase the demand for energy, whic

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