Arterial spurt patterns describe blood that is

• A. ejected in volume under pressure.
• B. deposited passively by gravity.
• C. transferred by contact with another surface.
• D. produced by cast-off from a blunt force.

Answer: (A)

Arterial spurt patterns reflect blood being forcibly ejected from an artery under the heart’s pumping pressure. The force behind each heartbeat pushes blood out at high velocity, creating a jet or series of spurts that can break into droplets on impact and form directional patterns that relate to the wound site and energy of the injury. This contrasts with gravity-driven bleeding, which drips passively and shows less energy and less directional speed. It also differs from transfer stains, which come from a wet surface contacting another surface and transferring material, not from pressure-driven ejection. And it’s not the same as cast-off from blunt force, which results from blood being flung off a weapon or object due to motion rather than blood under arterial pressure.