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Ämne: OT: Jag är skeptisk!
Skrivet av: Niclas nummer 2
Tid: 2007-03-21 13:23:00

Q13: Lara Beatty of Calgary, Canada writes: 
A friend and I were discussing cockroaches the other day, and she claims that a cockroach can live for about 6 years without it's head. Is this a true fact? 

A: Lara, 
 
Not true, but your friend is correct that a cockroach could live a long time, perhaps a month, without its head. The only reason we need our head for basic survival is: 
(1) We breath through our mouth or nose and the breathing rhythm is controlled in our brain. Cutting off our head would interphere with breathing although that could be maintained with a respirator. 
(2) Cutting off our head could lead to blood loss and a drop in blood pressure which would result in death due to lack of blood transport of oxygen and nutrition to our tissues. 
(3) Cutting off our head would prevent us from eating and we would die of starvation pretty quickly. 
 
All of these reasons for dying are not present in cockroaches and many insects in general: 
(1) Cockroaches breath through spiracles which are in each body segment and the blood does not carry oxygen to the tissues. The spiracles deliver air to each cell of the body through a set of tubes called tracheae. The brain does not control the breathing through the spiracles. 
(2) The cockroach does not have blood pressure the way a mammal does and so cutting off the head does not lead to uncontrolled bleeding. 
(3) The cockroach is a poikilotherm or cold blooded animal. They need much less food and a one day meal would be enough to last them a whole month as long as they were not extremely active. Without a head the cockroach would just sit around without doing anything much. 
 
All this along with a cool temperature could allow the cockroach to last about a month without need for their head, as long as they did not get infected with a mold, bacterium or virus, which could kill them prematurely. 




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Källa:
www.bio.umass.edu/biology/kunkel/cockroach_faq.html#Q13

Hela tråden

ÄmneTidSkrivet av
N Baggar09:16 den 21 mars 2007Gordon Eriksson
      N Baggar09:47 den 21 mars 2007Magnus (Gävle)
           N Andra irriterande kryp.09:55 den 21 mars 2007Peter (Hällingsjö)
                N OT: Jag är skeptisk!13:14 den 21 mars 2007Pyro
                     N OT: Jag är skeptisk!13:23 den 21 mars 2007Niclas nummer 2
                          N OT: Jag är nu lite mindre skeptisk! ;-) N/T16:20 den 21 mars 2007Pyro
                     N Belägg för kackerlackornas beständighet13:44 den 21 mars 2007Peter (Hällingsjö)
                          N Belägg för kackerlackornas beständighet13:46 den 21 mars 2007Niclas nummer 2
                               N Belägg för kackerlackornas beständighet13:53 den 21 mars 2007Hmm..
                                    N Belägg för kackerlackornas beständighet14:56 den 21 mars 2007Gordon Eriksson
                               N Belägg för kackerlackornas beständighet15:07 den 21 mars 2007Peter (Hällingsjö)
                                    N Belägg för kackerlackornas beständighet15:08 den 21 mars 2007Niclas nummer 2
                                         N Belägg för kackerlackornas beständighet15:34 den 21 mars 2007Roger O.
                                              N Fråga till RogerO.15:49 den 21 mars 2007Magnus (Gävle)
                                                   N Fråga till RogerO.15:59 den 21 mars 2007Roger O
                                                        N Fråga till RogerO.16:02 den 21 mars 2007Peter (Hällingsjö)
                                                             N Fråga till RogerO.16:34 den 21 mars 2007higgins
                                                             N Fråga till RogerO.17:02 den 21 mars 2007Roger O