because of different receptor types
Norepinephrine is also known as noradrenaline. It is released in the central nervous system which has a wide set of function in the body. This help in the activation of the flight or fight response by boosting the body to have an increased attention and reaction time. THis can increase the heart rate, dilate blood vessels and increased blood pressure however in other tissue function may vary due to the presence of various receptors that this neurotransmitter can activate.