Trauma Nurse Core Course (TNCC) Practice Exam

During the third impact of a motor vehicle crash, what occurs?

1. The driver collides with the steering wheel

2. The vehicle collides with a tree

3. The aorta is torn at its attachment with the ligamentum arteriosum

4. The airbag deploys and strikes the front seat passenger

The correct answer is: The aorta is torn at its attachment with the ligamentum arteriosum

During the third impact of a motor vehicle crash, the tearing of the aorta at its attachment with the ligamentum arteriosum is a critical event that can occur due to the forces exerted on the body during a collision. This portion of the aorta is particularly vulnerable in situations of rapid deceleration, such as a crash, where the body is rapidly halted while the internal organs and structures may continue to move forward. The first impact refers to the vehicle colliding with an object (like a tree), the second impact involves the occupant colliding with the interior of the vehicle (like the steering wheel), and the third impact pertains to the internal injuries sustained within the body as a result of these forces. Specifically, the aorta can suffer a tear or rupture due to sudden changes in motion, particularly where it is anchored to surrounding structures. This type of injury, often referred to as blunt aortic injury, is life-threatening and requires immediate medical intervention. Understanding this mechanism emphasizes the importance of monitoring for signs of internal injury in patients involved in motor vehicle crashes, especially in cases involving high-speed impacts or significant deceleration forces. This knowledge is crucial for trauma nurses and first responders in assessing and providing timely treatment for potentially catastrophic injuries.