Final answer:
A large hematoma over the frontal area of the skull after an unconscious 10-year-old boy fell from his bicycle and struck his head against the pavement is a sign of a traumatic brain injury.
Step-by-step explanation:
A large hematoma over the frontal area of the skull after an unconscious 10-year-old boy fell from his bicycle and struck his head against the pavement is a sign of a head injury. In this case, the cause of his unconsciousness can be suspected to be a traumatic brain injury.
When a strong blow is delivered to the brain-case portion of the skull, fractures can occur, which may result in bleeding inside the skull and subsequent injury to the brain. This can lead to the formation of a hematoma, which is a collection of blood between the brain and the interior of the skull. The pressure from the accumulating blood can cause unconsciousness and, if left untreated, can be life-threatening.