Endocrinology of reproduction half of pregnancy, progesterone and prolactin prepare the mammary glands for lactation. Estrogens and progesterone promote mammary epithelial cell proliferation resulting in the formation of the primary and secondary ductal structure. Progesterone induces formation of tertiary side-branches in the mammary glands during puberty and during the luteal phase of the menstrual cycle upon which lobuloalveolar structures form under the influence of prolactin. Prolactin stimulates lactogenesis. hCG appears to be soporific during pregnancy; levels of hCG correlate with sleep changes during pregnancy, and administration of hCG increases sleep in rats likely via neuronal LHCGR. Endocrinology of reproduction Hormonal regulation occurs at
Menstrual cycle few days (usually 3 to 5 days, but anywhere from 2 to 7 days is considered normal). The average blood loss during menstruation is 35 milliliters with 10–80 ml considered normal. Women who experience Menorrhagia are more susceptible to iron deficiency than the average person. An enzyme called plasmin inhibits clotting in the menstrual fluid. Painful cramping in the abdomen, back, or upper thighs is common during the first few days of menstruation. Severe uterine pain during menstruation is known as dysmenorrhea, and it is most common among adolescents and younger women (affecting about 67.2% of adolescent females). When menstruation