We are in the year 1902 and Ernest Starling injected ground duodenum, which is the connection of the small intestine to the stomach, into the jugular vein of a dog. Just within seconds, he was able to note the flow of pancreatic juice - just exactly like what happens when a dog consumes food! This, as we know today, is/was called "Secretin".
The word 'hormone' actually comes from Ancient Greek, which means to "stir into action", traveling through the blood stream. The endocrine system comprised of endocrine organs responsible for hormones. For example, the hypothalamus & pituitary in the brain, and our kidneys for mineral balance.
Image source: Wikipedia.com
As introduced just above, the primary conductor of the endocrine system is our pituitary gland. It typically produces a millionth of a gram of hormones per day, that is, 1 micro-gram. This minute amount leads to dramatic physiological effects on your body so it is absolutely crucial for the functioning of your body. Your body's performance will be severely hindered if there's something wrong with the pituitary gland! The gland is responsible for the cascading hormonal effect that releases to the other glands throughout your body.
We will talk about common types of hormones in your body next. But remember, as you read above, bigger is not always better!