Whats do drugs and alcohol do to the brain?

Uh...it depends on the drug. But fir alcohol, it blocks signals to your brain, making you very slow and can cause impulsive behavior. From what I researched.

they can cause brain cancer, short term memory, can affect the brain looks and works. these disturption can change mood and behaviour

b) the heart is a pump made of muscle and that is difficult to grow in the lab.