Secretion of human chorionic gonadotropin [HCG] only occur during pregnancy in the placenta. The concentration of this hormone increase rapidly during the first three months of pregnancy; the amount in the blood stream doubles every two to three days as the development of the placenta and embryo progress. The hormone reaches its maximum concentration peak around the sixth week of pregnancy and after this, its concentration decline.
<span>The high and low tide are caused by the gravitational forces between the earth and the moon</span>
It is a catecholamine. It is also known as adrenaline. It will increase the heart rate and other flight or fight responses.
