(Webster new world medicine dictionary. http://www.medterms.com/script/main/art.asp?articlekey=9973)
What are Hormones?
Hormones are chemicals that carry messages from organs of your body to your cells. The glands that secrete hormones are part of the endocrine system (pituitary, thyroid, adrenals and pancreas, to name a few) and work in large part to keep the body’s natural balance in check.
(Gary Gills, former about.com January 15, 2009. http://type1diabetes.about.com/od/glossaryofdiabetesterms/g/Hormones.ht
Give an explanation of two similarities and two differences in how Neurotransmitter and hormones function as messenger.
It is believed that the brain contains several hundred different types of chemical messengers (neurotransmitters) that act as communication agents between different brain cells. These chemical messengers are molecular substances that can affect mood, appetite, anxiety, sleep, heart rate, temperature, aggression, fear and many other psychological and physical occurrences.
Two differences between neurotransmitter and hormones is 1. Neurotransmitter has an instantaneously reaction while hormones have a late reaction. This is so because hormones are secreted by the endocrine glands in the bloodstream away from their function site and are carried by the circulation (bloodstream) to the target cell where they are effective. While Neurotransmitter is released at a specialized region of nerve cells and have to diffuses over a small gap (synaptic cleft) to the target cell.
2. Hormones have a long lasting reaction while Neurotransmitters has a short time reaction.