Question

alejandra has started to use heroin. how will this most likely affect her body systems? (1 point) it will fill the lungs with toxic material. it will release serotonin and dopamine to the brain. it will block the transmission of pain signals to her brain. it will speed up the central nervous system.

Explanation:

Heroin is an opioid. Opioids bind to opioid - receptors in the brain and body, and one of their main effects is to block the transmission of pain signals to the brain. While it can also affect neurotransmitter release, the most characteristic effect among the options given is pain - signal blocking. It does not fill lungs with toxic material in the primary sense, nor does it speed up the central nervous system (it depresses it). And while it can affect serotonin and dopamine release, the pain - blocking effect is more well - known and direct.

Answer:

It will block the transmission of pain signals to her brain.