Astrid spends a lot of time thinking about her own motivations and thoughts – about why she feels and believes and behaves the way she does. Astrid is best described as spending a lot of time in ____

As a potent poison, nicotine causes death by

A. stopping the heart. B. paralysis of respiration muscles. C. constricting blood vessels in the brain. D. increasing blood pressure until a stroke occurs.

Running to class, _____ is causing muscle fibers in your leg to contract so you can move, and it will stimulate the neurons you need for learning new information

a) serotonin b) dopamine c) endorphin d) acetylcholine