What type of trauma is considered penetrating?

Penetrating trauma refers to injuries where an object, such as a bullet or a knife, breaches the body's protective barriers and creates an open wound. A gunshot wound to the abdomen is a clear example of penetrating trauma, as the bullet penetrates the skin and can damage internal organs, leading to significant injuries and complications. This type of trauma requires immediate medical attention due to the potential for severe bleeding and internal damage.

In contrast, the other scenarios involve non-penetrating trauma. A bruise from a fall is typically a result of blunt force trauma, involving damage to blood vessels beneath the skin without breaking the skin. Similarly, a fracture from striking a hard surface is also a result of blunt force trauma, where the bone is impacted but the skin remains intact. Lastly, a concussion from a blow to the head involves internal brain injury caused by a jolt or impact, again without any penetration through the skull. Hence, the defining characteristic of penetrating trauma, as illustrated by the gunshot wound, is the actual breach of the body's surface, making it the only correct answer.