Chapter 16 – Part 3 The Reproductive System

1. Chapter 16 – Part 3The Reproductive System

2. Female Reproductive System • Functions of the Female Reproductive System (more complex than that of the male) • Produce the female gamete (ova or egg) • Nurture and protect a developing fetus during pregnancy

3. Female Reproductive System • Consists of the - • Ovaries • Duct System • Uterine tubes (fallopian tubes) • Uterus • Vagina • External genitalia

4. Female Reproductive System • Ovaries – Primary reproductive organs of a female • Produce the eggs or ova • Produce the following hormones: estrogens and progesterone

5. Female Reproductive System: Ovaries • Paired • Are the size and shape of almonds • They flank the uterus laterally

6. Support for Ovaries • Are secured to the lateral walls of the pelvis by the suspensory ligaments • Anchor to the uterus medially by the ovarian ligaments • They are enclosed and are held in place by a fold of peritoneum, the broad ligament

7. Support for Ovaries

8. Ovaries: Internal View • Composed of ovarian follicles(tiny sac-like structures) • Each follicle consists of - • Oocyte - immature egg • Follicular cells – one or more layers of very different cells that surround an oocyte

9. Ovarian Follicle Stages • Primary follicle – contains an immature oocyte • Graafian (vesicular) follicle – growing follicle with a maturing oocyte • As the follicle begins to ripen or mature, the follicle enlarges and develops a fluid-filled central region called an antrum.

10. Ovarian Follicle Stages • Ovulation – when the egg is mature the follicle ruptures and is ejected from the ovary • Occurs about every 28 days

11. Ovarian Follicle Stages • After ovulation, the ruptured follicle is transformed into a very different looking structure called the corpus luteum • The corpus luteum eventually degenerates

12. Interesting! • In older women, the surfaces of the ovaries are scarred and pitted, which attests to the fact that many eggs have been released.

13. The Female Duct System • Consists of the – • Uterine (Fallopian) tubes • Uterus • Vagina

14. Uterine (Fallopian) Tubes • Form the initial part of the duct system • Each of the tubes is about 4 inches long • Receive the ovulated oocyte • Provide a site where fertilization can occur

15. Uterine (Fallopian) Tubes • Extends medially from an ovary to the superior region of the uterus • Are enclosed and supported by the broad ligament

16. Uterine Tube Function • There is no actual contact between the uterine tubes and the ovaries • Fimbriae – finger-like projections that partially surround the ovary at the distal end of the uterine tube • Receive the oocyte

17. Uterine Tube Function • As an oocyte is expelled from an ovary during ovulation: • The waving fimbriae create fluid currents that act to carry the oocyte into the uterine tube • The oocyte is carried toward the uterus by a combination of peristalsis and the rhythmic beating of cilia inside the uterine tube • Takes 3–4 days

18. Uterine Tube Function • The usual site of fertilization is the uterine tube • To reach the oocyte, the sperm must swim upward through the vagina and uterus to reach the uterine tubes • This is difficult because they must swim against the downward current created by the cilia (like swimming against a tide)

20. Pelvic Inflammatory Disease • Bacteria sometimes infect the peritoneal cavity causing an extremely severe inflammation called pelvic inflammatory disease (PID). • Unless treated promptly, PID can cause scarring and closure of the narrow uterine tubes • One of the major causes of female infertility

21. Uterus • Located in the pelvis between the urinary bladder and rectum • Hollow organ • Functions of the uterus • Receive a fertilized egg • Retain the fertilized egg • Nourishe the fertilized egg

22. Uterus • In a woman who has never been pregnant: The uterus is about the size and shape of a pear • In pregnant women: The uterus increases tremendously in size to accommodate the growing fetus

23. Support for the Uterus • The uterus is: • Suspended in the pelvis by the broad ligament • Is anchored anteriorly by the round ligaments • Is anchored posteriorly by the uterosacral ligaments

24. Support for the Uterus

25. Regions of the Uterus Body – main portion Fundus – the superior rounded region above the entrance of the uterine tubes Cervix – narrow outlet that protrudes into the vagina

26. Walls of the Uterus • The walls of the uterus are thick and composed of three layers: • Endometrium – Inner layer • If fertilization occurs, the fertilized egg burrows into this layer (called implantation) and resides there for the rest of its development • This layer sloughs off every 28 days if no pregnancy occurs

27. Walls of the Uterus • The walls of the uterus are thick and composed of three layers (cont.): • Myometrium – Bulky middle layer • Is composed of interlacing bundles of smooth muscle • Plays an active role during the delivery of a baby, when it contracts rhythmically to force the baby out of the mother’s body • Serous layer – outer visceral peritoneum

28. Cervical Cancer • Cancer of the cervix is common among women between the ages of 30-50. • Risk factors include: • Frequent cervical inflammation • Sexually transmitted diseases • Multiple pregnancies • An active sex life with many partners • A yearly Pap smear is the single most important diagnostic test for detecting this slow-growing cancer

29. Vagina • Vagina – Thin-walled tube about 3-4 inches long that extends from the cervix to the exterior of body • Behind the bladder and in front of the rectum • Often called the birth canal • Provides a passageway for the delivery of an infant and for the menstrual flow to leave the body • Receives the penis (and semen) during sexual intercourse

30. Vagina • The distal end of the vagina is partially closed by a thin fold of mucosa called the hymen. • It is very vascular and tends to bleed when it is ruptured during the first sexual intercourse. • Its durability varies: • In some females, it is torn during a sports activity, tampon insertion, or pelvic examination • Occasionally, it is so tough that it must be ruptured surgically if intercourse is to occur.

31. Female Reproductive System

32. External Genitalia (Vulva) • The female reproductive structures that are located external to the vagina are the external genitalia. • Are also called the vulva and include the - • Mons pubis • Labia • Clitoris • Urethral orifices • Vaginal orifices • Greater vestibule glands

33. External Genitalia (Vulva) • Mons pubis • Fatty, rounded area overlying the pubic symphysis • Covered with pubic hair after puberty

34. External Genitalia (Vulva) • Labia – Skin folds • There are two: • Labia majora – Two elongated hair-covered skin folds that run posteriorly from the mons pubis • Labia minora – Two delicate hair-free skin folds; enclosed by the labia majora

35. External Genitalia (Vulva) • Vestibule • Region that is enclosed by the labia majora • Region that contains the external opening of the urethra, followed posteriorly by that of the vagina

36. External Genitalia (Vulva) • Greater vestibular glands – A pair of mucus-producing glands that flank the vagina (one on each side) • Their secretion lubricates the distal end of the vagina during intercourse

37. External Genitalia (Vulva) • Clitoris – Small protruding structure that corresponds to the male penis • Composed of sensitive erectile tissue that becomes swollen with blood during sexual excitement • Located anterior to the vestibule

38. External Genitalia (Vulva) • Perineum – The diamond-shaped region between the anterior end of the labial folds, the anus posteriorly, and the ischial tuberosities laterally