Which statement correctly describes coup and contrecoup injuries?

Which statement correctly describes coup and contrecoup injuries?

• A. Coup injuries occur at the impact point on the skull
• B. Contrecoup injuries occur at the impact point on the skull
• C. Both injuries occur at the same site
• D. Contrecoup injuries are caused by penetrating trauma

Answer: (A)

The main idea is understanding where the injury lands relative to the point of impact during head trauma. Coup injuries occur at the site of impact on the skull, where the blow directly compresses the brain against the inner surface and causes injury there. Contrecoup injuries, by contrast, happen on the opposite side, as the brain continues to move inside the skull and strikes the far inner surface after the initial impact. These injuries come from acceleration–deceleration forces in a closed head injury, not from penetrating trauma. So the statement that coup injuries occur at the site of impact is the correct description. The other options misstate the location or mechanism: contrecoup is not at the impact point, injuries do not have to occur at the same site, and contrecoup is not caused by penetrating trauma.

The main idea is understanding where the injury lands relative to the point of impact during head trauma. Coup injuries occur at the site of impact on the skull, where the blow directly compresses the brain against the inner surface and causes injury there. Contrecoup injuries, by contrast, happen on the opposite side, as the brain continues to move inside the skull and strikes the far inner surface after the initial impact. These injuries come from acceleration–deceleration forces in a closed head injury, not from penetrating trauma. So the statement that coup injuries occur at the site of impact is the correct description. The other options misstate the location or mechanism: contrecoup is not at the impact point, injuries do not have to occur at the same site, and contrecoup is not caused by penetrating trauma.