The "fleshless skin"? What other type of skin were you distinguishing it from? Anyway, the blood vessels in the scalp are mostly small, so though bleeding can occur quite easily, it's likely not to be very heavy.
In most other areas of the body, with the exception of the shins, there is flesh. Shins, like the scalp, bleed freely when the skin tears and can be difficult to hold together. Having coped with tears in the scalp, I can vouch for how how long they can go on bleeding.