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

How much minerals should be taken for management of obesity, How much Miner...

How much Minerals should be taken for management of obesity? A diet high in sodium may promote retention of fluid in the body. Moderate restriction in the use of common/table s

Joint, Ask question #Minimum 100 words what is joint accepted#

Ask question #Minimum 100 words what is joint accepted#

Zoology, give an account of specific characters of phylum porifera

give an account of specific characters of phylum porifera

Explain the disadvantage of contact plate method, Explain the Disadvantage ...

Explain the Disadvantage of Contact Plate Method? These plates are suitable for sampling the surfaces having low contamination, like pre-cleaned and sanitized surfaces. This is

Define major arthropod classes, Q. How are the three major arthropod classe...

Q. How are the three major arthropod classes characterized according to the presence of wings? Arachnids and Crustaceans do not have wings. Most insects have wings.

What are enantiomers, Enantiomers: Select one: a. Have the same molec...

Enantiomers: Select one: a. Have the same molecular weight b. Have the same connectivity c. Are mirror images d. Are non-superimposable e. All of the above

Explain pulmonary atresia with intact ventricular septum, Explain Pulmonary...

Explain Pulmonary Atresia With Intact Ventricular Septum ? The direct communications between RV and PA is absent. The PDA is major source of blood flow to lungs From Aorta. The

What is cyclosis, Cyclosis is a type of internal cell movement in which an ...

Cyclosis is a type of internal cell movement in which an oriented flow of circulating material is formed and maintained in the cytoplasm by the action of microfilaments. Cyclosis i

PHYUM, HOW MANY PHYLUM OF ANIMALS?

HOW MANY PHYLUM OF ANIMALS?

What do you mean by the coelom, Q. What is the coelom? To which structures ...

Q. What is the coelom? To which structures do coeloms give birth? Are all animals coelomate? Coeloms are cavities delimited by mesoderm and Coeloms originate the cavities where

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