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. It binds to opioid - receptors in the brain and nervous system, blocking the transmission of pain signals. It does not fill lungs with toxic material directly in the way described, does not release serotonin and dopamine in the way stated (it affects opioid - receptors more directly), and it depresses rather than speeds up the central nervous system.

Answer:

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