Final answer:
The pterion is the area of the head where only direct pressure and elevation should be used to control severe bleeding caused by injury. Other methods, including tourniquets or pressure points, are not advised due to the risk of further complications. This response is part of the body's life-saving feedback mechanism that facilitates blood clotting to prevent blood loss.
Step-by-step explanation:
The injury described is specifically to the head, impacting the pterion, which is located on the lateral side of the head. If an artery located deep to the pterion is harmed, direct pressure and elevation are the immediate measures for controlling life-threatening bleeding. The pterion is a clinically significant landmark because it's near a major arterial branch that feeds the skull and brain coverings. A severe blow to this area can lead to a hematoma, which, if left untreated, may cause death due to increasing pressure on the brain. Imaging techniques like MRI or CT scanning can localize the damage, but on-the-scene decisions might have to rely on simpler methods. The body’s response to such injury is a positive feedback mechanism that accelerates blood clotting to prevent excessive blood loss.