Final answer:
Opiates activate the descending pain-inhibitory pathway and reduce the transmission of pain impulses to the brain, making the statement true.
Step-by-step explanation:
Opiates do indeed activate the descending pain-inhibitory pathway in addition to decreasing the impulses travelling to the brain. This is true because opiates function by binding to specific opioid receptors in the nervous system and gastrointestinal tract. Their activation results in the inhibition of pain signals and modulation of pain perception. Moreover, the descending pathways that opiates activate originate in the brain and extend into the spinal cord, which can suppress the transmission of pain signals back to the brain. Therefore, the statement that opiates activate the descending pain-inhibitory pathway in addition to decreasing impulses travelling to the brain is true.