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WonderBody fact

A resting adult breathes about 12 to 15 times a minute, which adds up to roughly 20,000 breaths a day. Each quiet breath moves about half a litre of air, so the lungs handle something like 10,000 litres a day, almost all of it without any conscious effort.

Human biology

Health

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Breathing is controlled by respiratory centres in the brainstem, the part of the brain just above the spinal cord. They set the rhythm automatically, even during sleep, and adjust it using sensors that monitor the blood. The main trigger is not a lack of oxygen but a rise in carbon dioxide, which makes the blood more acidic; that build-up is what makes holding your breath feel uncomfortable. Unlike the heartbeat, breathing can also be taken over at will, which is why you can speak, sing, sigh or slow your breath on purpose. Rates are higher in children: a newborn baby breathes 30 to 40 times a minute.

Türkçe oku
Dinlenen bir yetişkin dakikada 12-15 kez nefes alır; bu, günde aşağı yukarı 20.000 nefes eder. Sakin bir nefeste yaklaşık yarım litre hava girip çıktığı için akciğerlerden günde 10.000 litre kadar hava geçer ve bunun neredeyse tamamı biz farkına bile varmadan olur.

Solunumu, beyin sapında, yani beynin omuriliğin hemen üzerindeki bölümünde bulunan solunum merkezleri yönetir. Bu merkezler ritmi uykuda bile kendiliğinden belirler ve kanı izleyen algılayıcılardan gelen bilgilere göre ayarlar. Nefes almayı tetikleyen asıl şey oksijen eksikliği değil, kanı daha asidik yapan karbondioksit birikimidir; nefes tutmayı zorlaştıran da bu birikimdir. Kalp atışından farklı olarak solunumu istediğimiz zaman kendi kontrolümüze alabiliriz; konuşabilmemiz, şarkı söyleyebilmemiz, iç çekebilmemiz ya da nefesimizi bilerek yavaşlatabilmemiz bu sayededir. Çocuklarda solunum hızı daha yüksektir: Yeni doğmuş bir bebek dakikada 30-40 kez nefes alır.

Sources and further reading

Background reading: Breathing
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