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

Define essential parts of photocolorimeter - monochromators, Define Essenti...

Define Essential Parts of Photocolorimeter - Monochromators? This is a means of selecting a sufficiently narrow waveband. Early colorimeters used glass filters that transmitted

Explain procedure for determination of the quality of milk, Explain Procedu...

Explain Procedure for Determination of the Quality of Milk? 1. Prepare methylene blue solution by dissolving 1 mg methylene blue in 250 ml of sterile distilled water. 2. Aft

Explain therapeutic diet planning, Explain therapeutic diet planning Al...

Explain therapeutic diet planning All detailed dietary modifications  should be presented with choices,  clear guidelines, menu guidance and supporting  information  as  to  al

Pharmacological treatment, Diuretic Therapy One of the aims of treatment...

Diuretic Therapy One of the aims of treatment of congestive heart failure is directed toward controlling salt and water retention (central or peripheral edema). Diuretics provid

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

How the blood sugar level is maintained at a stable level, Discuss how the ...

Discuss how the blood sugar level is maintained at a stable level in the well fed and fasting state In  the fed state, clearance of blood  glucose is mainly by  liver via gluc

Sterility assurance, All the efforts that go into the preparation of instru...

All the efforts that go into the preparation of instruments are futile if the sterilization process itself is not successful. There is no way of seeing that instruments are sterile

Show the examples of arthropods, Q What are the few examples of arthropods?...

Q What are the few examples of arthropods? Ants, crabs, cockroaches, shrimps, flies, spiders and scorpions are examples of arthropods.

Which dsdna is imprtant for dna purification, Which of the following proper...

Which of the following properties of dsDNA is imprtant for DNA purification? A. Hydrophilic B. Positively charged phosphate backbone C. Can only bind to divalent cations

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