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

Explain centrifuge - microbiological apparatus and equipment, Explain the C...

Explain the Centrifuge - Microbiological Apparatus and Equipments? Centrifuge is used for separating the substance in liquid or concentrating the microorganisms on the basis of

Nutritional management for diarrhoea, Q. Nutritional management for diarrho...

Q. Nutritional management for diarrhoea? The conservative concept of treatment for diarrhoea was not in favour of feeding adequate amount of food. However, with the identificat

Nutrition, prove oxygen is produced during photosynthesis in the presence o...

prove oxygen is produced during photosynthesis in the presence of light

Fallopian tube, Fallopian tube: There are two fallopian tubes connec...

Fallopian tube: There are two fallopian tubes connected to the uterus one on each side of it. The ovum released from the ovarian follicle enters the fallopian tube. Th

Atypical distribution of pleural fluid, Q. Atypical Distribution of Pleural...

Q. Atypical Distribution of Pleural Fluid? i) Lamellar effusion: These are shallow collections of fluid between the chest wall and the lung surface. ii) Subpulmonic

Why the enzymatic action is highly specific, Why can it be said that the en...

Why can it be said that the enzymatic action is highly specific? The enzymatic action is highly specific because only exact substrates of one enzyme bind to the activation cent

Show the efficient contraceptive method, Q. Why is the use of condoms not j...

Q. Why is the use of condoms not just a contraceptive method but also a health protection behavior? The use of condoms besides being an efficient contraceptive method also help

Clinical reasoning , Upon admission the DPU nurse notes: Fasting sta...

Upon admission the DPU nurse notes: Fasting status - fasted from 12 midnight, no morning medication taken. Consent - signed Pre anaesthetic check Test results

Illustrate oil-bearing materials, Illustrate oil-bearing materials Oil...

Illustrate oil-bearing materials Oil contents for vegetable oil-bearing materials vary between 18% and 68% of the total weight of the seed, nut, kernel or fruit as indicated i

What are the two main types of endocytosis, What are the two main types of ...

What are the two main types of endocytosis? Endocytosis can be divided as pinocytosis or phagocytosis. In pinocytosis small particles on the external surface of the membrane ex

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