Endocrine organs are activated to release their hormones by humoral, neural or hormonal stimuli. Emerging adulthood and adolescence differ significantly with regard to puberty and hormonal development. The menstrual cycle is governed by hormonal changes. These results were correlated to alterations in hormonal and metabolic activity. During periods of hormonal imbalance, women exhibit a peak in sexual activity. Hypothyroidism is another possible cause of dwarfism that can be treated through hormonal therapy. These physical changes are the first visible signs of neural, hormonal, and gonadal function changes. Biological differences include chromosomes and hormonal differences. Other genetic predispositions include the density of the breast tissue and hormonal levels. Environmental and hormonal factors can affect stomatal development. Drospirenone has been suggested for potential use as a progestin in male hormonal contraception. Patients should avoid other precipitants including hormonal triggers. Effects on humans include disruption of various hormonal mechanisms. Surgery that affects the hormonal levels in women include oophorectomies. Normal skeletal development is inhibited due to a large variety of factors, mostly hormonal.