1. Menstrual Cycle

3. Menstrual Cycle
Definition – series of events controlled by hormones preparing the uterus for reception of the fertilized egg cell

4. Menstruation (Days 1-5) – lining of uterus is discharged
a. Corpus luteum dies – then lining is discharged
b. Progesterone – when corpus luteum dies, amount of this hormone decreases in quantity due to failure of egg fertilization
c. Follicle-stimulating hormone – begins to increase

5. Follicle Stage (proliferative phase)
[DAYS 6-14]
a.  FSH levels continue to rise
b.  Several follicles develop, only one will ovulate
c.   Follicle secretes estrogen
d.  Estrogen  more LH being made
e.  Uterus lining thickens
f.    LH peaking triggers ovulation

6. Corpus Luteum Stage (secretory phase)
[DAYS 14-28]
a.  Ruptured follicle  corpus luteum
b.  Corpus luteum makes progesterone  thicker endometrium
c.   High levels of progesterone inhibits FSH production

7. Menstrual Cycle

10. During pregnancy, estrogen and progesterone levels rise dramatically (about 300x). At birth, they drop drastically and prolactin production increases to begin milk production

11. Animals having a menstrual cycle (humans, apes, monkeys)
6. Estrous cycle
a. Females become receptive to mating
b. Sex hormones
c. Males sense
d. Eggs

12. Birth Control Pills = High levels of progesterone (or a related hormone) trick body into thinking it is pregnant  NO OVULATION
Some also thicken the mucus around the cervix to prevent sperm into the uterus as well as making it difficult to implant on the uterine wall.
How do you still menstruate?
7 placebo pills a month