AP BIOLOGY

Detailed explanation-1: -The major phases of the menstrual cycle are-menstrual phase, follicular phase and luteal phase. The cycle starts with the menstrual phase, when menstrual flow occurs and it lasts for 3-5 days.

Detailed explanation-2: -“Normal” menstruation can differ widely from woman to woman-anywhere from three to seven days of bleeding is considered normal, and each full menstrual cycle can last anywhere from 21 to 35 days. Three days of bleeding, which may seem short, is still considered normal as long as you’re menstruating regularly.

Detailed explanation-3: -Menstruation (Days 1-5) The Follicular Phase (Days 6-14) Ovulation (Day 14) The Luteal Phase (Days 15-28)

Detailed explanation-4: -The luteal phase begins after ovulation. It lasts about 14 days (unless fertilization occurs) and ends just before a menstrual period. During most of the luteal phase, the estrogen level is high. Estrogen also stimulates the endometrium to thicken.