Final answer:
The dorsal column pathway is the white matter tract that conveys discriminatory sensory signals such as vibration and touch, and testing its integrity can help locate spinal injuries.
Step-by-step explanation:
The white matter tract responsible for carrying discriminatory sensory signals such as vibration and touch is the dorsal column pathway. This tract conveys fine touch, vibration, and proprioceptive information. By testing a patient's ability to distinguish between light touch and vibration, healthcare providers can assess the integrity of this specific ascending pathway.
In the spinal cord, the dorsal column carries information ipsilaterally and decussates at the level of the medulla, whereas the spinothalamic pathway, which primarily conveys pain and temperature, decussates at the level of spinal cord entry and ascends contralaterally. Therefore, testing these two tracts' function through sensory stimuli helps in determining which pathway may be compromised. For example, a patient recovering from a motor vehicle accident may display sensory deficits that can help to locate and assess the extent of injury to these pathways.