One possibility for opioid mechanism is that action in the _______ causes descending fibers from the brainstem to directly inhibit dorsal horn cells that transmit _______ information.
A) periaqueductal gray; pain
B) somatosensory cortex; vibration
C) thalamus; heat
D) pons; light touch

Question

Quizplus · Accepted Answer

The periaqueductal gray (PAG) is a key region in the brain for regulating pain. Stimulation of the PAG produces analgesia (pain relief), which occurs via descending fibers to the dorsal horn (part of the spinal cord) that inhibit pain transmission. Therefore, opioids may produce their analgesic effects by activating the PAG, which then sends inhibitory signals to the dorsal horn cells that transmit pain information.

One Possibility for Opioid Mechanism Is That Action in the _______