Why, when you poke yourself or cut yourself, does it often take 10-20 seconds for you to start bleeding?

Question

Why, when you poke yourself or cut yourself, does it often take 10-20 seconds for you to start bleeding?

In: 8

Answer 1

In small injuries, surface tension and capillary action tends to make most of the blood continue through the severed blood vessels rather than escape into the wound channel. However, once enough blood escapes up through the would channel, these same forces draw more blood into the wound channel. This takes a bit of time.