I read a lot of vampire fiction, so I read a lot of stuff about fangs puncturing femoral arteries and carotids. I thought I should clarify some about the difference between arteries and veins (and how it affects you paranormal writers in the audience).
Arteries generally contain oxygenated blood, meaning the blood flowing through those suckers tend to be a bright red. Arteries are under high pressure, varying between peak pressure (systolic) and low pressure (diastolic), depending on which part of the heart pumping cycle you’re on. This causes your pulse.
There are generally very few arteries in a given area, meaning that any damage to them can be catastrophic. Arteries tend to be harder to find, deeper.
Veins are under low pressure, and are abundant. Where an area (e.g. your arm) might only have two arteries, you’ll have a broad network of veins. This, all in all, makes veins a better choice to puncture. Lower pressure makes it less likely the patient (or victim) will bleed out (or get blood all over your vampire) and because there are more veins, you are less likely to suffer consequences if the vein is damaged in the process.
Veins carry deoxygenated blood, and the blood will be a darker color red. Veins are also closer to the skin.
Veins don’t have a pulse.
Small cuts to arteries could spray as far as 30 feet, while larger injuries might only be a few feet, six feet being average. Death occurs in as little as 30 seconds, but could take minutes or even long enough to get to assistance if the artery is small enough. Most of the popular arteries (e.g. carotid, femoral) are too large to get help, I believe.
Interestingly, the type of damage can have a major effect. A clean, full cut will cause something called vasospasm, which will cause the artery to close off, preventing blood loss. However, partial cuts and peppering (like fang holes) will not result in vasospasm and the body will bleed out.
Death by Exsanguination
Your body will go into cardiovascular collapse once 50% of your blood volume is lost.
A Vampire’s Choice…
So, when deciding on what to bite, you should take those things into account. Of course, if your vampire is a vicious killer, he doesn’t mind if the victim bleeds to death, but the higher pressure of arterial blood will make for a messy meal. Arterial blood will spray all over him, making for an awkward retreat in public, and making it hard for his activities to go unnoticed. Of course, this isn’t a concern in private, and could make for some interesting, and gruesome, visuals.
For those good vamps out there, veins are the way to go. Easier to reach and less likely to end up with a dead victim. Also good for those romance writers out there.