The pain-relieving chemicals naturally produced by the nervous system belong to a class of substances called ___; this class also includes ___.
A) stimulants; cocaine and amphetamine
B) depressants; alcohol and valium
C) opiates; heroin and morphine
D) opiates; alcohol and valium

Question

Quizplus · Accepted Answer

The pain-relieving chemicals produced by the nervous system are known as opiates, which includes heroin and morphine. Stimulants (choice A) increase alertness and energy and include drugs like cocaine and amphetamine. Depressants (choice B) slow down the activity of the brain and include alcohol and valium. Therefore, C is the correct answer. Alcohol and valium (choice D) belong to the depressant class, not the opiate class.

The Pain-Relieving Chemicals Naturally Produced by the Nervous System Belong