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

Hypomagnesemia, H y p o ma g n e s e m i a It is also known...

H y p o ma g n e s e m i a It is also known as grass staggers or lactation or grass tetany and results in clonic and tonic muscular spasms and convulsions. E

Name the implant failures, Implant failures On the basis of the stage w...

Implant failures On the basis of the stage when problems occurs implant failures can be classified as : i) Before Abutment Connection. ii) During Abutment Connection.

Define future projections in the field of public nutrition, Define Future P...

Define Future Projections in the Field of Public Nutrition? We discussed earlier that the field of public nutrition has existed for a long time, although not by this name. A he

Where in the body is the thyroid gland located, Q. Where in the body is the...

Q. Where in the body is the thyroid gland located? The thyroid is located in the anterior cervical region (frontal neck) in just below the larynx and front of the trachea and i

Oxygen transport in blood, Oxygen Transport in Blood All four respirat...

Oxygen Transport in Blood All four respiratory pigments are adapted to load and unload oxygen effectively in I the habitats where they have evolved, whether animals live on la

How to do glucose test, How to do Glucose test A glucose test is a type...

How to do Glucose test A glucose test is a type of blood test used to determine the amount of glucose in the blood. There are several different kinds of glucose tests:  "

Photophosphorylation, explain the role of cyclic photophosphorylation in p...

explain the role of cyclic photophosphorylation in photosynthesis

What is the structure that maintains identical chromatids, What is the stru...

What is the structure that maintains identical chromatids bound? The structure that maintains identical chromatids bound is the centromere. Cell Nucleus Review - Image Diver

Explain fixed performance system in oxygen therapy, Explain fixed performan...

Explain fixed performance system in oxygen therapy? Fixed Performance Systems: These devices are capable of delivering a fixed, preset concentration of oxygen regardless of t

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