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WonderBody fact

Wound healing moves through four overlapping stages: clotting to stop the bleeding, inflammation to clean the area, growth of new tissue to fill the gap, and remodelling, in which the new tissue slowly strengthens and settles into a scar.

Human biology

Health

The story behind the card

Within minutes of an injury, platelets, tiny cell fragments in the blood, stick to the damaged vessel and, together with a protein mesh called fibrin, form a clot. In the inflammation stage, white blood cells clear away bacteria, debris and dead cells, which is why a fresh wound can look red, warm and swollen. Next, new blood vessels grow, cells called fibroblasts lay down collagen, the protein that gives skin its strength, and skin cells creep across to close the surface. In the final stage the collagen is reorganised and the scar slowly fades. This can last a year or longer, and even then a scar reaches only about 80 percent of the strength of unbroken skin.

Türkçe oku
Yara, birbirinin içine geçen dört aşamada iyileşir: Önce kan pıhtılaşıp kanamayı durdurur, ardından vücudun savunma tepkisi olan inflamasyonla bölge temizlenir, sonra boşluk yeni dokuyla dolar ve son olarak bu doku yavaş yavaş güçlenip yara izine dönüşür.

Yaralanmadan birkaç dakika sonra, kandaki küçük hücre parçacıkları olan trombositler hasarlı damara yapışır ve fibrin adlı bir proteinin oluşturduğu ağla birlikte pıhtıyı meydana getirir. İnflamasyon aşamasında akyuvarlar bakterileri, yabancı maddeleri ve ölü hücreleri temizler; taze bir yaranın kırmızı, sıcak ve şiş görünmesi bu yüzdendir. Ardından yeni kan damarları oluşur, fibroblast denen hücreler deriye sağlamlığını veren kolajen proteinini üretir ve deri hücreleri yaranın üstünü kapatmak için ilerler. Son aşamada kolajen yeniden düzenlenir ve yara izi yavaş yavaş solar. Bu aşama bir yıl ya da daha uzun sürebilir; sonunda bile yara izi, sağlam derinin ancak yüzde 80'i kadar dayanıklı olur.

Sources and further reading

Background reading: Wound healing
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