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-   -   Why aren't hunger thirst and (the need to) sleep considered reflexes? (http://www.physicsforums.com/showthread.php?t=665292)

RabbitWho Jan19-13 11:55 AM

Why aren't hunger thirst and (the need to) sleep considered reflexes?
 
A reflex is an automatic and involuntary response of a living thing to the presence of a stimulus. A reflex is usually a movement, but it can be the activation of secretion in a gland.

Is it because there is no particular stimulus? Not having eaten, drank, slept for a while is not considered a stimulus?
Is it because you have to learn what thirst is, you have to learn that drinking solves the problem?

Thank you.

Simon Bridge Jan19-13 07:13 PM

Re: Why aren't hunger thirst and (the need to) sleep considered reflexes?
 
A reflex is performed without conscious thought - there is no pressing conscious need to do it you just do.
Properly triggered, a reflex is something you cannot choose not to do ... where you can choose to, say, starve to death.
There is also a relatively uncomplicated cause and effect involved in a reflex.

Consider also:
do you have a "death reflex" that is triggered by the application of large quantities of high-speed lead?

RabbitWho Jan20-13 06:23 AM

Re: Why aren't hunger thirst and (the need to) sleep considered reflexes?
 
Ok thanks! :)


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