Overview of the Female Reproductive System: Structures and Functions

1. The Reproductive System16b.

2. Female Reproductive System • Ovaries • Exocrine – ova • Endocrine – estrogen & progesterone • Hormones prepare egg for fertilization, regulate menstrual cycle, maintain pregnancy • Duct System • Uterine tubes (fallopian tubes) • Uterus • Vagina • External genitalia PRESS TO PLAY FEMALE REPRODUCTIVE SYSTEM OVERVIEW ANIMATION

3. Female Reproductive System Figure 16.8a

4. Ovaries • Composed of ovarian follicles (sac-like structures) • Structure of an ovarian follicle • One Oocyte • Many Follicular cells Figure 16.7

5. Ovarian Follicle Stages • Primary follicle – contains an immature oocyte • Graafian (vesicular) follicle – growing follicle with a maturing oocyte • Ovulation – when the egg is mature the follicle ruptures • Occurs about every 28 days • The ruptured follicle is transformed into a corpus luteum which degenerates

6. Support for Ovaries • Suspensory ligaments – secure ovary to lateral walls of the pelvis • Ovarian ligaments – attach to uterus • Broad ligament – a fold of the peritoneum, encloses suspensory ligament

7. Support for Ovaries Figure 16.8b

8. Uterine (Fallopian) Tubes • 4” long • Receive the ovulated oocyte • Viable for 24 hours • Provide a site for fertilization • Attaches to the uterus (transport mature ovum from ovary to uterus) • Does not physically attach to the ovary • Distal end – infundibulum with finger-like projections = fimbriae • Supported by the broad ligament

9. Uterine Tube Function • Because uterine tubes open to peritoneal cavity, you can get infections • Gonorrhea, PID • Fimbriae – finger-like projections at the distal end that receive the oocyte • Cilia inside the uterine tube slowly move the oocyte towards the uterus (takes 3–4 days) • Fertilization occurs inside the uterine tube

10. Uterus • Located between the urinary bladder and rectum • Size of a pear • Hollow muscular organ • Functions of the uterus • Receives a fertilized egg • Retains the fertilized egg • Nourishes the fertilized egg

11. Support for the Uterus • Broad ligament – attached to the pelvis • Round ligament – anchored interiorly • Uterosacral ligaments – anchored posteriorly

12. Support for the Uterus Figure 16.8b

13. Regions of the Uterus • Body – main portion • Fundus – area where uterine tube enters • Cervix – narrow outlet that protrudes into the vagina (neck of uterus) • PAP smear

14. Walls of the Uterus • Endometrium • Inner layer • Allows for implantation of a fertilized egg • Sloughs off if no pregnancy occurs (menses) • Myometrium – middle layer of smooth muscle • Active during labor • Serous layer – outer visceral peritoneum = perimetrium

15. Vagina • Extends from cervix to exterior of body • 3-4” long muscular tube • Behind bladder and in front of rectum • Serves as the birth canal • Receives the penis during sexual intercourse • Hymen – fold of mucosa; partially closes the vagina until it is ruptured

16. External Genitalia (Vulva) • Mons pubis, labia, clitoris, urethral & vaginal orifices, greater vestibular glands • Mons pubis • Fatty area overlying the pubic symphysis • Covered with pubic hair after puberty Figure 16.9

17. External Genitalia (Vulva) • Labia – skin folds • Labia majora • Labia minora • Greater vestibular glands • Batholin’s glands • Secrete mucus & lubricating fluid into vagina Figure 16.9

18. External Genitalia • Vestibule • Enclosed by labia majora • Contains opening of the urethra and the greater vestibular glands (Bartholin’s glands), produce mucus • Clitoris • Contains erectile tissue • Corresponds to the male penis

19. Oogenesis • Production of ova • The total supply of eggs are present at birth • Ability to release eggs begins at puberty • Reproductive ability ends at menopause • Oocytes are matured in developing ovarian follicles

20. Oogenesis • Oogonia – female stem cells found in a developing fetus • Oogonia undergo mitosis to produce primary oocytes • Primary oocytes (~2 million) are surrounded by cells that form primary follicles in the ovary • Oogonia no longer exist by the time of birth

21. Oogenesis • Primary oocytes are inactive until puberty • 400,000 left at puberty • Follicle stimulating hormone (FSH) from anterior pituitary causes some primary follicles to mature • Meiosis starts inside maturing follicle • Produces a secondary oocyte and the first polar body • Meiosis is completed after ovulation only if sperm penetrates • Two additional polar bodies are produced in addition to the one ovum

22. Oocyte with sperm

23. LH causes ovulation • Use ~500 ova over a lifetime • Ovum – large, nonmotile, lots of nutrients

24. Oogenesis Figure 16.10