Reproductive System - Female & Birth Control

" If they are standing at that time ... !?! "

Ovary - Produce gametes (eggs) and hormones.

Fallopian tube (Oviduct) - Tube from the overies to the uterus and where fertilization occurs.

Uterus - If pregnancy occurs the fetus implants here.

Cervix - The bottom opening of the uterus

Vagina - Outside opening of the female reproductive tract.

Clitoris - An erectile structure similar to the male penis and as large as a penis.

Secondary oocyte (N) - What is ovulated each month. It has completed meiosis 1.

Estrogen - Female sex hormone. At week 10 causes the primary sex characteristics - growth of reproductive organs(ovaries & uterus). At Puberty causes the development of the secondary sex characteristics - breast development, pelvic broadening, and female fat and muscle distribution.

Ovarian cycle - Puberty to Menopause - Involves development of the egg and other cells in the ovary.

          Preovulatory phase - Days 1-13 There is a small peak in FSH which stimulates a primary follicle. Just before ovulation estrogen levels peak and cause LH and FSH levels to peak. Day 13 LH triggers the release of an egg or secondary oocyte.

                    Primary follicle - An egg + surrounding follicle cells.

          Ovulation - Day 14 - The secondary oocyte bursts out of the ovary.

          Postovulatory phase - Days 15 - 28 The follicle cells after ovulation become a structure called the corpus luteum.

                    Corpus luteum - It secretes the hormones estrogen and progesterone.

                              Progesterone - Stops contractions of the uterus for implantation and causes the endometrium to thicken.

Menstrual cycle - (puberty ---> menopause) Involves changes in the inner wall of the uterus which is the endometrium.

          Menstrual phase (Menstruation) - Where the old inner wall of the uterus is shed along with the blood vessels in it.

                    Endometrium - Inner wall of the uterus where the fertilized egg implants.

Vasectomy / Tubal ligation - (almost 100%) Cut and tie the vas deferens or cut and tie the fallopian tubes - prevents the possibility of pregnancy. These 2 methods have the lowest failure rate.

IUD (Intrauterine Device) - Hormonal and Copper - 99% effective, Copper kills sperm and increases cervical mucus (hard for sperm to swim through) and prevents implantation for 12 years. (Hormonal one lasts for 5 years) Reduced #of periods.

Implanon now Nexplanon - 99% effective, it is 1 capsule (Progestin) implanted under the skin and good for up to 3 years. Reduced # of periods. Has to be removed.

Depo-Provera - This is 4 injections of a progesterone-like steroid (Progestin) a year. Effectiveness is 96%.

The Pill / Patch - 95% effective and contains the hormones Estrogen and Progesterone. It mimics the postovulatory phase of the hormonal cycle, so no eggs are ovulated. All 4 methods prevent LH spike- no ovulation.

Male or Female Condom - 85% effective. Are also effective against sexually transmitted diseases like AIDS

Calendar Method / Rhythm Method - One avoids sex for 3 days before and after ovulation. Lowest Effectiveness about 70%. Can use temp to determine ovulation - not very easy to get accurate readings.

Morning After Pills - In a kit called Preven - Or Plan B Progestin pills prevent LH spike, effective up to 3 days after unprotected sex - 85% effective.

RU 486 - The abortion pill. It blocks progesterone receptors in the uterus. Then it is followed by giving prostaglandins (causes cramps) to start contractions and expel the embryo. Then it is 99% effective. Can expel an embryo up to 9 weeks old.

The Pathway of Gametes


Ovary --> Fallopian Tube (Oviduct) --> Uterus --> Cervix --> Vagina

Return to Greg Sievert's GB 100 Syllabus
Last updated on 18 April 2018