how does a cat purr?

Answers:
So it is not unusual for an animal to have a physical reaction to happiness. Cats show happiness by purring. They may also purr when startled or upset.

It turns out that cats have special wiring! The wiring travels from the brain to the muscles in the voice box, and this wiring is able to vibrate the muscles so that they act as a valve for air flowing past the voice box. The muscles work both during inhalation and exhalation, which creates the impression that cats can purr continuously. The air passes through the valve, which opens and closes rapidly to create the purring sound.

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Nobody knows how they do it! Another feline mystery unsolved!

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Not even scientists know how a cat purrs so good luck finding out!

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Wow, the question of the century - no one knows! It's a mystery, just like the cat!

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They just do.

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is'nt it vibrations of the vocal cords? can't human's purr?

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It curves it's tongue to a 33.7 degree angle in it's mouth, then hums!

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cause they cant woof

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If you could answer that, you'd be nominated for a Noble Prize! Seriously, no one seems to know.

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A cat purrs by it turns out that cats have special wiring! The wiring travels from the brain to the muscles in the voice box, and this wiring is able to vibrate the muscles so that they act as a valve for air flowing past the voice box. The muscles work both during inhalation and exhalation, which creates the impression that cats can purr continuously. The air passes through the valve, which opens and closes rapidly to create the purring sound.

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Dont know.I care that mine does.To me it says he feels happy,safe, and content.
Pretty damn cool isnt it.

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If your intereseted in getting answers to a question like this I recommend a book called "the cat whisperer". It tells you all the sorts of things that us mere humans dont understand or know about our feline friends. Excellent read.

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They PURR because they can't talk or may be yours can and if iit can wll ya tell it to tell mine to stop wetting and poohing ever where please

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Vibrations in the cats larynx is whats commonly thought. Noone knows what the reason for this is. as in evolutionary reason because they dont just purr when theyre content, but also when theyre ill.

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How does a cat purr?( sorry its long %26 boring!!)

Sounds forming the voice of animal (including humans), originate from vibrations of voice ligaments in larynx, when air comes through them. A larynx is a part of a respiratory tract, through which an air passes in lungs and moves away. Shortening of ligaments, due to increase in tension causes a higher pitch of sound. And usual cat purring goes this way.

However purring of different representatives of the cat family, including our domestic cats consists of quick alternate impulses of sound, arising in larynx. Every individual sound is caused by quick alteration of air pressure after right and left voice ligaments are separated. Larynx muscles are stimulated frequently by nerve impulses coming from twenty to thirty times a second. Every moment this happens, voice ligaments close up, and, as a result, an air pressure rises. When stimulation of muscles stops, voice ligaments drift apart and make the released air to produce a sound.

During inhalation and exhalation (though there's a small interval between) the events are ordered as stated above, and if one lends his ear, he may able to make them out. Furthermore, during inhalation, in order to prevent the dispersion of air (that is, chaotic loss of air pressure) the diaphragm is constricted not permanently (that is usual) but in a series of consistent impulses, alternating with constrictions of throat muscles.

The intensity of purring - its' loudness - depends on the power of stimulation of animal, for example, on stroke, or talking with it. Often purring even in presence of a man is not loud, delicate. But if one to put his finger on a cat throat he'll easily feel larynx vibrations.

The alternative theory of mechanism of purring has been put forward, but it seems quite unreal. This theory assumes that purring is caused by the increase of speed and turbulence of blood stream in vein, that sends back blood from the back of body. Turbulence produces vibration inside blood vessel in the point where it crosses chest, and then this vibration pass inside head along respiratory tract. Yet this hypothesis needs extra research.