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

Of which cells is the nervous tissue constituted, Of which cells is the ner...

Of which cells is the nervous tissue constituted? How is the generic function of this tissue related to the characteristics of the main cell type that forms it? The nervous tis

Closed heart surgery, Closed Heart Surgery Blind operations and access...

Closed Heart Surgery Blind operations and access is obtained into the heart through incision on the ventricular or atrial wall. Commonest closed heart surgery done is m

Enzymology, please i want detailed explanation on the mechanism of enzyme c...

please i want detailed explanation on the mechanism of enzyme catalysis

Explain the classification of enzymes, Classification of Enzymes It has...

Classification of Enzymes It has been a long tradition  of giving enzymes names ending in 'ase'. The only major exception to this 'ase' is the proteolytic enzymes, whose names

What are the joints, What are the joints Joints are the place of artic...

What are the joints Joints are the place of articulation between two or more bones, or between a bone and a cartilage. Due to the presence of a number of joints, the movement

How phosphorus in blood is presented, How Phosphorus in Blood is presented?...

How Phosphorus in Blood is presented? Phosphorus in Blood is Present as: 1.  Inorganic phosphorus in the form of HPO 4 or H 2 PO 4 2.  Organic or ester phosphorus such

Predict whether narrowing or widening of the blood vessels, Body temperatur...

Body temperature is homeostatic ally regulated around a set point. Given your knowledge of negative feedback and homeostatic control system, predict whether narrowing or widening o

Explain sexually-transmitted diseases, Sexually-transmitted diseases M...

Sexually-transmitted diseases Many travelers have new sexual contacts during their journeys and are at increased risk for acquiring sexually transmitted diseases including HIV

Improvement of cereal proteins - mutual supplementation, Define Improvement...

Define Improvement of cereal proteins - Mutual supplementation? Improvement of cereal proteins: Cereals, in general, are limiting in lysine and threonine while legumes, milk, m

What are deciduous trees, What are deciduous trees? The Deciduous trees...

What are deciduous trees? The Deciduous trees are plants that lose their leaves in a period of the year and in the case of the deciduous trees of the temperate forest the fall

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