27. Why does blood clot?
Bleeding occurs when our skin gets damaged and the blood vessels
near the surface are broken. This bleeding does not continue for long
because our blood contains special substances, which form a clot that
dries and checks the flow of blood.
An enzyme called thrombin present in the blood, initiates the process
of clotting. This acts upon a protein called fibrinogen and changes it
to fibrin. Fibrin consists of many long fibres that become entangled
into each other, trapping blood cells as they form. A clot is
consequently formed of fibrin and blood cells and only the colourless
blood serum passes through it. The clot forms a protective covering
over the wound.
Vì sao máu đông?
Sự chảy máu xảy ra khi da bị tổn thương và các mạch máu
gần bề mặt bị đứt. Sự chảy máu không thể tiếp tục trong
thời gian lâu vì máu của chúng ta có chứa những chất đặc
