AEMCA Practice Exam

In deceleration injuries, where is the aorta most commonly sheared from?

1. Ligamentum arteriosum

2. Aortic arch

3. Left ventricle

4. Superior vena cava

The correct answer is: Ligamentum arteriosum

In deceleration injuries, the aorta is most commonly sheared from the ligamentum arteriosum. This is because the ligamentum arteriosum is a fixed point that connects the aorta to the pulmonary artery, and during rapid deceleration, such as in a car accident, the body may come to a stop suddenly while the aorta continues to move in response to the forces of inertia. This can lead to tearing at the point where the aorta is anchored by the ligamentum arteriosum. The other options represent areas or structures that are not typically associated with such shearing injuries. The aortic arch is a broader section and less likely to experience localized shearing forces compared to the area at the ligamentum arteriosum. The left ventricle, while commonly involved in traumatic injuries, does not play a direct role in the mechanics of aortic shearing during deceleration. The superior vena cava, being a major vein, is also not a site where shearing typically occurs in the context of deceleration forces affecting the aorta. Thus, the ligamentum arteriosum is understood to be the critical anatomical landmark where such aortic injuries occur during severe deceleration, highlighting the unique vulnerability of that specific region to shear forces