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

Pulmonary ventilation, Pulmonary Ventilation: Pulmonary ventilation is th...

Pulmonary Ventilation: Pulmonary ventilation is the process by which gasses flow between the atmosphere and lung alveoli. Air moves into the  lungs when air pressure  inside the

Explain wound healing and formation of woven bone, Wound healing and format...

Wound healing and formation of woven bone Stage 1: Wound healing and formation of woven bone (callus) (2 to 6 weeks) The ability of the body to respond to the "trauma" indu

Determine st-segment elevation, Q. Determine ST-Segment Elevation? Ans...

Q. Determine ST-Segment Elevation? Ans. Exercise induced ST-segment elevation is common in subjects with post MI stress tests in leads where Q-waves are present. It has be

Give examples of diseases caused by bacteria, Give three examples of diseas...

Give three examples of diseases caused by bacteria, Diseases caused by bacteria contain tonsillitis, blood poisoning, scarlet fever, tuberculosis, typhoid, diphtheria, food poi

Agro industrial-non-edible and other minor oilseed cakes, NON-EDIBLE AND OT...

NON-EDIBLE AND OTHER MINOR OILSEED CAKES Besides the annually cultivated oilseed crops namely, groundnut, sesame, mustard, linseed, coconut, cotton, sunflower and safflower, I

Define integrity of epithelial tissues, Define Integrity of Epithelial Tiss...

Define Integrity of Epithelial Tissues? Vitamin A is essential for the integrity of the mucous-secreting cells. In fact vitamin A maintains the health of epithelial cells that

Define the clinical manifestations of underweight, Define the Clinical Mani...

Define the Clinical Manifestations of Underweight? Underweight may predispose to fatigue, lethargy and breathlessness. Iron-deficiency anaemia is usually seen because the diet

What are the etiological agents of malaria, What are the etiological agents...

What are the etiological agents of malaria? The etiological agents of malaria are protozoans of the genus Plasmodium. There are four dissimilar types of plasmodia that cause ma

Determine the cylindrical body of nematodes brought, Compared to platyhelmi...

Compared to platyhelminthes which physiological problem have the cylindrical body of nematodes brought? How was that problem solved? The cylindrical shape of nematodes made imp

Whcih group of individual animals and plants called species, Q. Whcih group...

Q. Whcih group of individual animals and plants called Species? A group of individual plants and animals that are fundamentally alike is treated as a ,species. Species is a par

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