Neural circuits, Biology

Assignment Help:

Neural Circuits

The simple all are none activities of a single neuron can hardly provide the adaptability needed for the constant changes faced by the organism in its internal and external environments. Information about the external environment is integrated with signals arising within the organism and transmitted to effectors to elicit a coordinated response. Thus each neuron forms a unit in a communication circuit. A survey of the features of the nervous system in the animal groups at various points on the phylogenetic tree shows that a long evolutionary process has produced the outstanding complex structure of the human brain.

83_Neural Circuits.png

Figure: Nerve Net in Jelly Fish

Protozoans are single celled organisms and clearly cannot have a nervous system. An examination of the electrical properties of the protozoan cell membrane would, however, show many similarities to those of nerve cells including electrical potential changes and currents associated with activity. Coelenterates are of great interest neurologically since they are the first animals to possess a true nervous system. The coelenterate nervous system consists of a diffuse network of neurons that are distributed throughout the body wall. Such a simple and primitive nervous system is termed a nerve net in which neurons are dispersed mostly at random. Though primitive, this arrangement serves the need of a radially symmetrical animal whose food and enemies may approach from all directions. The animal's reaction depends on the strength of the stimulus. Only a part of the body reacts to a weak stimulus and a strong stimulus causes the entire animal to respond. From such diffuse primitively organised system of nerve cells, evolution has produced a complex organized nervous system such as that of man. The system of local nerve nets, however continues to exist even in many advanced invertebrate groups and in the intestines of vertebrates.


Related Discussions:- Neural circuits

What are the degenerative diseases of the nervous system, Q. What are the m...

Q. What are the main degenerative diseases of the nervous system? The major degenerative diseases of the nervous system are Alzheimer's disease and Parkinson's disease. The

Non-succulent perennials, Non-succulent perennials These are actually t...

Non-succulent perennials These are actually the true xerophytes or drought resistants, because they possess a number of morphological, anatomical and physiological characterist

Animal classification, Explain metachrosis in frogs? How it is different fr...

Explain metachrosis in frogs? How it is different from change of skin colour of chemleon?

How is excretion done in fishes, Q. How is excretion done in fishes? Fi...

Q. How is excretion done in fishes? Fishes have a pair of kidneys that filtrate the blood, bony fishes excrete nitrogen as ammonia NH3 (they are ammoniotelic) and cartilaginous

How are the plant tissues classified, How are the plant tissues classified ...

How are the plant tissues classified according to their functions? Plant tissues are separated into growth (embryonic) tissues, supporting, filling and photosynthetic tissues (

Amoeba, Place a slide of Amoeba (common species is A. proteus) under tlie l...

Place a slide of Amoeba (common species is A. proteus) under tlie lnicroscope and focus it under low power (5x x 5x), and observe it carefully. Amoeba looks like an irregular colou

Whether the drug-susceptible or drug-resistant phenotype, True or false? It...

True or false? It would be difficult to assess whether the drug-susceptible or drug-resistant phenotype in a population of Mycobacterium tuberculosis was more fit in an environment

The cerebrum, The cerebrum is clearly the most interesting part of the brai...

The cerebrum is clearly the most interesting part of the brain from the point of view of cognitive neuroscience. The cerebrum consists of highly symmetrical left and right hemisphe

What is respiration quotient, a) Where casparian strips situated in a plant...

a) Where casparian strips situated in a plant body are and what are they made up of? Mention its function. b) What is respiration quotient (RQ)? Under what conditions will th

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