AP Psychology Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

Endorphins are natural, opiatelike neurotransmitters that play a critical role in the body's ability to manage pain and create feelings of pleasure. They are produced by the central nervous system and pituitary gland, primarily in response to stress or discomfort, and they bind to the same receptors in the brain as opioids do, thus helping to alleviate pain and promote a sense of well-being. This is why they are often referred to as "feel-good" hormones.

The other options do not accurately reflect the role and nature of endorphins. Enzymes that digest proteins pertain to a different biological function entirely and do not relate to neurotransmission. Electrochemical signals for emotional responses are more in line with the roles of neurotransmitters such as serotonin or dopamine, but do not specifically describe endorphins. Lastly, the notion of toxins harming nerve cells is opposite to the function of endorphins, which are protective and promote health rather than harm.