Eli5: How come after you cut yourself it takes a few seconds to start bleeding?


Eg. A small cut on your finger. I understand there is more blood over time, but why none at all for the first few seconds? Thank you.

In: 4

Depending on your activity level at the moment of the cut, your blood pressure, thickness etc the blood can take a few seconds to start or can gush out immediately, also depending on the depth and location of the injury, what size and type of vessel got injured. Theres alot of factors that contribute to your blood flow.
A theory for when you are in a “resting” state and you get cut, the elastic potential of the blood vessels will cause them to recoil and collapse, potentially withholding the blood until the blood pressure cause by the heart beat pushes the blood forward through the system and out the injured vessels.