Noradrenaline, also known as norepinephrine, is a chemical that functions primarily as an excitatory neurotransmitter, but also as a hormone. It is made from the amino acids phenylalanine and tyrosine, and is stored and released from neurons throughout the sympathetic nervous system. Noradrenaline is continuously released at low levels in order to maintain optimal blood pressure. Similar to adrenaline, it is also vital for our fight or flight response, and in times of stress it increases heart rate, blood pressure and glucose levels, widens our pupils and air passages in the lungs, and reduces the function of non-essential systems.Rogers, K. (n.d.). Norepinephrine. [online] Encyclopedia Britannica. Available at: [Accessed 19 Nov. 2018]. (2016). Norepinephrine vs Epinephrine: What’s the difference?. [online] Available at: [Accessed 29 Nov. 2018].