Question

Which of the following usually will cause the pupils of the eyes to dilate?

1) The combination of PCP and Heroin
2) PCP
3) Hallucinogens
4) D. Narcotic Analgesics

Answer 1

Hallucinogens and PCP are known to cause pupil dilation due to their impact on neurotransmitter systems, unlike narcotic analgesics that usually result in pupil constriction.

Step-by-step explanation:

The substances that usually cause the pupils of the eyes to dilate include hallucinogens and drugs like PCP (Phencyclidine). Hallucinogens such as LSD affect the serotonin system, leading to various perceptual changes, and PCP acts as an antagonist of the NMDA glutamate receptor. Neurotransmitters like norepinephrine and adrenergic agents such as phenylephrine, when binding to certain receptors in the eye, cause pupillary dilation or mydriasis. Therefore, both hallucinogens and PCP can cause pupils to dilate. In contrast, narcotic analgesics, which are opioids, generally do not lead to pupil dilation but rather to pupil constriction (miosis).