Why do head wounds bleed so heavily?

specifically surface head wounds and why do they belead more than if i were to have a surface wound on my arm?

because there are many more blood vessels in the head than in the arm, particularly small capillaries. The brain requires the most oxygen and blood flow of any part of the body, hence, the number of capillaries are much greater, and are much more dense in the head and face. It has nothing to do with the brain 'pumping' blood, or the location of the wound being near arteries, nor the 'thin' skin.

It simply is the capillaries and small vessels are much more densely populated in the head

Edit: The amount of misinformation in this thread in response to such a simple question is staggering... People really need to read more.

Because there are so many blood vessles in the face and neck and they are close to the skin.

All head wounds do not bleed so heavily. It depends upon where the wound is. You have arteries feeding your brain, that do not exist in your arms. a wound anywhere near the entry of those arteries can cause heavy bleeding.
The best solution is to wear a hard hat, or helmet when you are engaged in a dangerous pursuit.

I actually know this one because I recently had a minor head wound that made me look like I was dying!! It's because your brain is quickly pumping blood through and the rate at which it is flowing is alot faster than in your arm.

the head gets more blood because it has the brain. it has a lot of vessels in a small area.

the reason is the top of your head is the thinnest part of the skin hence when you get a wound on your head it tens to bleed more than a simple cut on your arm cause your head has a lot of blood surrounding the Brain and skull

Less skin