Two reasons that activation by the sympathetic division of the ANS has a long duration are that the neurotransmitter _____ is inactivated more slowly than _____, and also acts through _____ systems in the cell rather than directly operating ion channels.

3000+ review questions on anatomy and physiology. 

Anatomy refers to the internal and external structures of the body and their physical relationships, whereas physiology refers to the study of the functions of those structures.