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24 September 2014
Human Body & MindScience & Nature

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Fact files

Organs - Voice box

System: Respiratory

Location: At the top of your windpipe

Physical description: Hollow, tubular structure about 3-4 cm across

Function: To create sounds and prevent food from entering your airways

Sound machine

Your voice box, or larynx, is a hollow tubular structure made of cartilage. It is connected to the top of your windpipe.

Inside your voice box are two bands of tissue that form your vocal cords. When you speak or sing, muscles pull these cords together. The air passing through the cords makes them vibrate. You can hear these vibrations as sounds.

The shorter your vocal cords are and the faster they vibrate, the higher the sound you produce. In both girls and boys the voice box and vocal cords grow during puberty and cause their voices to deepen. In girls, this change may be hardly noticeable with their voices dropping by just a couple of tones. But boys' voice boxes grow considerably. They also tilt to a different angle in the neck and can start to stick out as a prominent 'Adam's Apple'. Boys' voices can drop by as much as an octave.

Guardian of the airways

On the upper part of your voice box there is a flap called the epiglottis. When you swallow, your voice box rises and your epiglottis forms a lid over its opening. This blocks the passageway to your respiratory tract and prevents food and other foreign substances from entering your airways. This is why your epiglottis is sometimes called the 'guardian of the airways'.

If anything other than air enters your voice box, you automatically cough to clear your airways.

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