For women in spontaneous labor, contractions are usually two to five minutes apart, last from 30 to 60 seconds, and have moderate strength. The easiest way to assess the power of labor is to time the frequency and duration of the contractions (from the beginning of one to the beginning of the next).
Melatonin, hormone secreted by the pineal gland, a tiny endocrine gland situated at the centre of the brain. Melatonin was first isolated in 1958 by American physician Aaron B. Lerner and his colleagues at Yale University School of Medicine.
The pituitary gland is often referred to as the master gland of the body, since it regulates many activities of other endocrine glands. Located above the pituitary gland is the hypothalamus. The hypothalamus decides which hormones the pituitary should release by sending it either hormonal or electrical messages. In response to hormonal messages from the hypothalamus, the pituitary gland releases the following hormones: 1  GH (growth hormone) â increases size of muscle and bone.  THS (thyroid stimulating hormone) â stimulates the thyroid gland to release T3 and T4 to stimulate metabolism in other cells throughout the body.