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

What event marks the beginning of the menstrual cycle, Q. What event marks ...

Q. What event marks the beginning of the menstrual cycle? What is the blood concentration of FSH, LH, estrogen and progesterone in this phase of the cycle? By convention the me

Define intermediate level of the numeric pyramid, In the short term what wi...

In the short term what will happen to the levels above and below a population of secondary consumers of a numeric pyramid if a large number of individuals from this population dies

Explain the main function of the digestive system, Explain the main  funct...

Explain the main  function of the digestive system The major function of the digestive system is to ingest the food materials, digest it to absorbable end products, absorb the

Kin selection, While explaining the concept of natural selection, we have s...

While explaining the concept of natural selection, we have stressed the fact that natural selection is synonymous with differential or non-random reproduction. Natural selection ai

What is bigunnides, Q. What is Bigunnides? Bigunnides: They are atni d...

Q. What is Bigunnides? Bigunnides: They are atni diabetic drugs which do not affect the output of insulin. These are preferred to sulphony lureas because they do not cause we

Explain adverse effects of amantadine, Adverse Effects of amantadine  ...

Adverse Effects of amantadine  Amantadine may cause anorexia, nausea, peripheral edema and, particularly in the elderly, minor CNS effects such as nervousness, anxiety, insomn

Explain the glass test tubes - food microbiology, Explain the Glass Test Tu...

Explain the Glass Test Tubes - Food Microbiology Sterile glass tubes are used for culturing microorganisms in liquid or solid media. Sterility in tubes is maintained by using c

What is neurotransmitter, What is neurotransmitter Consider Neuron B i...

What is neurotransmitter Consider Neuron B in the frog central nervous system whose plasma membrane has a previously unknown channel that is selectively conductive to a newly

Experiment to test your hypothesis, Deinococcus radiodurans is a bacterium ...

Deinococcus radiodurans is a bacterium that was isolated from cooling ponds in and around nuclear power plants. It is highly resistant to ionizing radiation. Propose an hypothesis

Can you explain likar system with electrodes, Q. Can you explain Likar Syst...

Q. Can you explain Likar System with Electrodes? The 12 lead Mason - Likar system with electrodes is used. The plastic adhesive electrodes has self contained electrode jelly in

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