First, what is the difference between arterial and venous bleeding? A short anatomy lesson first. Arteries are on the forward side meaning this is blood that has just left the heart. In order for your heart to get blood through the body, it has to pump. The heart's pumping is something you can feel... it's called your pulse. Whereever you feel your pulse is an artery.
Venous blood is on the return side. This is blood that has off loaded its oxygen and is on its way back to the lungs. There's not as much pressure, per se, in those vessels.
When you puncture an artery, it spurts, pretty dramatically, with each heartbeat. I saw a demonstration once of how long it would take someone to "bleed out" from an untreated arterial bleed to the knee which houses the popliteal artery. Now compared to some, this would be a smaller sized artery compared to your aorta. Any guesses?
About three minutes.
Venous bleeding doesn't have the characteristic spurting with each heartbeat. It generally oozes though it can ooze quite a bit. Venous bleeding can also be deadly if there is enough of it left untreated.
Arterial bleeding is generally harder to control than venous bleeding. You have to apply a lot of pressure to get it to stop. Hence, my dismay at how a character who sustained an injury to his neck, likely the carotid artery, could have made it to the hospital with a simple dressing in place.
What do you think?