Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: paul.fr on 24/12/2007 22:26:31
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Suppose they have their neck bent, standing besides a pool of water, how do they actually swallow "uphill"?
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If you were to stand on your head, could you not still drink a gallon of beer?
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Great question Paul - and the answer is in exactly the same way we do, and is also the reason why astronauts can swallow under the microgravity conditions in space.
As turnipsock suggests above, and surprising as it sounds, you can swallow whilst standing on your head. This is because the oesophagus (gullet) connecting your mouth to your stomach is a muscular tube and when food or liquids are pushed into it from the mouth a swallowing reflex is initiated. This triggers the muscle to contract in sequence around the oesophagus from top (mouth end) to bottom (stomach end), propelling the contents forwards towards the stomach. You can think of it as similar to a Mexican wave at a football stadium, with the food or liquid surfing along just ahead of the wave.
In this way the contents are pushed into the stomach, irrespective of whether you are lying, standing, upside down or in orbit. Giraffes are no different, with the exception that their oeesophagus is slightly longer!
Other interesting facts about a giraffe's neck:
- It's about 2 metres long.
- It weighs over a quarter of a tonne!
- Despite its great length it contains the same number of vertebral bones as a human (7).
- To push blood all the way up their necks to keep the brain supplied, giraffes have one of the highest blood pressures of any mammal, 280/180 mmHg
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modify your question and try it out yourself!! Cause nothing I say compares to the response of the person above!