Biology 30 Investigation of the Menstrual Cycle Lab Key

Biology 30 Investigation of the Menstrual Cycle Lab Key Procedure: Study the graphs, and observe how the levels of hormones affect each other as well as the follicle and endometrium. Use the Analysis questions to analyze and interpret the graphs. Analysis 1. During which days of the menstrual cycle does the level of FSH increase? /1 FSH levels are high during the follicular stage (days 1-5). /1 FSH levels spike just before ovulation (day 14). What happens to the follicle during this time? /1 Follicle is maturing (days 1-5) in preparation for /1 follicle bursts and releases mature ovum/ovulation (day 14). (Follicle releases estrogen and some progesterone.) 2. On which day is the level of LH in the bloodstream at its highest? What event occurs immediately after this peak? /1 Day 13 or 14 = highest level of LH leads to the /1 follicle bursting and releasing the ovum. (After bursting the follicle begins to develop into the corpus luteum.) 3. What event is associated with the decline of LH in the blood? /1 The secretion of progesterone & some estrogen from the corpus luteum/luteal phase 1/1 egg travels Fallopian tube 4. During which days of the cycle does the level of estrogen in the blood increase most rapidly? What happens in the uterus during this time? /1 Days 9-14 = estrogen levels. (Day 1 part marks Follicle matures = estrogen levels = inhibit anterior pituitary from releasing FSH = triggers release of GnRH from hypothalamus LH) /1 Uterine lining OR endometrium begins to thicken. 5. During which days of the cycle does the level of progesterone in the blood increase most rapidly? /1 After Day 14. Before Day 21. ( progesterone after ovulation) What happens in the uterus during this time?