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Trying to provide all necessary information about IMMUNITY and IMMUNE SYSTEM

Coelentrates|Animal toxins|Immunology|Toxicology.

Posted by Mumtaz khan Saturday, 28 January 2012

         Scyphozoa-Jelly fish,Physalia.
* Sting Apparatus:
* All the coelentrates posses thousands of microscopic stinging cells or nematocysts.
* Nematocyst is a special type of cell containing venom aparatus.
* The apparatus consists of  long coiled thread,the broad base of which is called butt,which may be provided with sharply pointed barbs.
* The opening is guarded by a long stiff spine called Cnidocil.
* Normally the stinging cell is encased in a capsule but on stimulation the thread is ejected out and the poison is injected into victim.
* The nematocysts are activated by mechanical or chemical stimulation.
* Venom:
* Hypothalamus and Haemothalasins both of which are proteins are the venoms found in coelenterates.
* It also contains phospholipases,neurotoxin,nephrotoxin,Ag proteins and hyaluronidases.
* Venom differ in composition in different nematocysts.
* The protein component of venom are heat liable,degradable by proteolytic agents.
* Effects:
* The initial effect of contact with nematocysts is a kind of stinging sensation and when the toxin is injected,a shooting pain is experienced.
* The venom produces dermal reactions such as redness of skin,numbness,swelling like responses,when nematocysts are injected.
* The victim often experiences a shock and within minutes he may become unconscious.
* Persons in water are unable to reach land and hence are in great danger of drowning.
* Other symptoms are nausea,vomitting,muscle-cramps,severe pain,inability to move,backbone,loss of speech,inability to swallow etc
* The most fatal cases develops paralysis and coma.


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