Norepinephrin

There are three kinds of hormones in the human body:

steroid hormones are lipid soluble, enter into cells themselves, and need to latch onto a water soluble transport to move around in the bloodstream. 

amino acid derivatives are water soluble, bind to outside receptors which then trip an interior signal 

and 

polypeptides, which are water soluble and stay inside the endocrine cell. 

Norepinephrine is an amino acid derivative that is produced in the adrenal medulla and postganglionic neurons. It is synthesized from tyrosine, an amino acid which is hydroxylised into L-DOPA. Which is then decarboxylated into Dopamine, then beta oxidized into norepinephrine. 

While the compound is still dopamine, it is transported into synaptic vesicles where it can be released or prevented from being released by many different substances including cocaine and steroids. It is transported by the same transporter (VMAT) as epinephrine, isoprenaline. 

It binds and activates adrenergic receptors, but since different cells have different adrenergic receptors norepinephrine affects each one differently. Generally it produces the fight or flight response by increasing heart rate, releasing glucose, and increasing blood flow to muscles. 

 the hormone norepinehrine has a positive feedback loop, which is regulated by cortisol. negative feedback is the maintenance of homeostasis. Positive feedback is the temporary spike of hormones necessary for the body to act, say in childbirth of in the fight or flight response.

link to mp4:
https://drive.google.com/file/d/0BwjRyvqE8KK3bHczUGZCN3Y1VUE/edit?usp=sharing

Sources:
http://www.caam.rice.edu/~cox/wrap/norepinephrine.pdf
http://e.hormone.tulane.edu/learning/types-of-hormones.html
http://www.pennmedicine.org/health_info/body_guide/reftext/html/endo_sys_fin.html
http://chipur.com/2010/05/11/teachin-tuesday-hpa-axis/