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WonderBody fact

Most people are slightly taller in the morning than in the evening, because the soft discs between the vertebrae soak up fluid overnight and are squeezed flatter through the day.

Human anatomy

HealthScience

The story behind the card

Each disc has a tough outer ring and a soft, gel-like centre that is mostly water, and together the discs make up roughly a quarter of the length of the spine. When you stand, sit or walk, your body weight slowly presses fluid out of them, so by evening most people are around a centimetre shorter than when they got up. Lying down takes the load off, and the discs soak fluid back up during the night. In space nothing presses down on the spine at all, so it lengthens: NASA reports that astronauts can grow by up to 3 per cent, roughly 5 centimetres, during a long mission. They shrink back to their usual height soon after returning to Earth.

Türkçe oku
Çoğu insan sabahları akşama göre biraz daha uzundur. Omurlar arasındaki yumuşak diskler gece yatarken sıvı çekip kabarır, gün boyunca da vücut ağırlığı altında yeniden yassılaşır.

Her diskin sert bir dış halkası ve çoğu sudan oluşan, jöle kıvamında yumuşak bir çekirdeği vardır; diskler hep birlikte omurganın boyunun aşağı yukarı dörtte birini oluşturur. Ayakta durduğunuzda, oturduğunuzda ya da yürüdüğünüzde vücut ağırlığınız bu disklerdeki sıvıyı yavaş yavaş dışarı iter. Bu yüzden çoğu insan akşam olduğunda sabahkinden bir santim kadar kısadır. Yatınca yük kalkar ve diskler gece boyunca sıvıyı yeniden emer. Uzayda omurgaya binen hiçbir ağırlık olmadığı için omurga uzar: NASA'ya göre astronotlar uzun görevlerde boylarının yüzde 3'üne, yani 5 santimetreye kadar uzayabilir. Dünya'ya döndükten kısa süre sonra eski boylarına inerler.

Sources and further reading

Background reading: Human height
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