Refractory period (sex) after orgasm in which further sexual stimulation does not produce excitement. While the refractory period varies widely among individuals, ranging from minutes to days, most men cannot achieve or maintain an erection during this time, and many perceive a psychological feeling of satisfaction and are temporarily uninterested in further sexual activity; the penis may be hypersensitive and further sexual stimulation may feel painful during this time frame. An increased infusion of the hormone oxytocin during ejaculation is believed to be chiefly responsible for the male refractory period, and the amount by which oxytocin is increased may affect the length of
Breast milk of milk of similar quality to that of mothers in developed countries. There are many reasons a mother may not produce enough breast milk. Some of the most common reasons are an improper latch (i.e., the baby does not connect efficiently with the nipple), not nursing or pumping enough to meet supply, certain medications (including estrogen-containing hormonal contraceptives), illness, and dehydration. A rarer reason is Sheehan's syndrome, also known as postpartum hypopituitarism, which is associated with prolactin deficiency and may require hormone replacement. The amount of milk produced depends on how often the mother is nursing and/or pumping: the more