Introduction: Menstrual Cycle Activity 1

Phases of the Menstrual Cycle There are four phases of the menstrual cycle 1. Menstruation (period) 2. Follicular Phase 3. Ovulation 4. Luteal Phase In this activity, you and your group members will explore these four phases of the menstrual cycle

Phase 1: Menstruation Commonly know as a woman’s “period” During this phase: 1. the lining of the uterus wall known as the endometrium breaks away 2. The menstrual fluids from this breakage such as blood, cells from the uterus lining and mucus exit the vagina It occurs from days 1-5

As you can, as the endometrium begins to fall away, the menstrual fluids exit the uterus area and through the vagina.

Phase 2: Follicular Phase This phase actually starts on the first day of menstruation up to day 13 (Day 1-13) During this period, the ovaries produce 5 to 20 structures called “follicles” These are tiny nodules or cysts Each follicle houses an immature egg Only one of the follicles will mature into an egg The others will die

The growth of the follicle stimulates (causes or promotes) the lining of the uterus to thicken. Uterus wall is thickening The individual yellow circles are each of the follicles produced in the ovaries.

Phase 3: Ovulation Ovulation occurs when a mature egg breaks out of the follicle and exits the ovary It generally occurs from days 10-18 The egg makes its way into the fallopian tube and towards the uterus This is when a woman is most likely to get pregnant.

The life span of the egg is only 24 hours The life span of the egg is only 24 hours. Unless it meets a sperm while traveling in the fallopian tube, it will die!

Phase 4: Luteal Phase Occurs from days 15-28 The follicle that the mature egg was in transforms into a structure known as corpus luteum The corpus luteum releases the hormone progesterone and a small amount of oestrogen. The release of these hormones keep the lining of the uterus thick.

There are two scenarios that can take place during the lateal phase The egg is fertilized The egg is NOT Fertilized While traveling in the fallopian tube, the mature egg is fertilized by a sperm cell The fertilized implants itself on the uterus wall If no health complications occur, then the woman will become pregnant The egg travels into the uterus and disintegrates The corpus luteum dies The lining of the uterus wall falls away This is the start of menstruation again