Lab Manual - Female Reproductive Anatomy

Assignments:

Learning Objectives:

Upon completion of this session, the student will be able to:

  1. Trace the skeletal and ligamentous boundaries of the perineum, and define the anal and urogenital triangles.
  2. Identify the superficial features of the external genitalia in the female.
  3. Describe the structure, contents, and course of the pudendal canal.
  4. Trace the branching pattern of the internal pudendal vessels and the pudendal nerve.
  5. Differentiate between male and female urethrae.
  6. Identify the components of the external genital organs and give the homologues in each of both sexes.
  7. Describe structure and function of the erectile bodies.
  8. Identify the muscles and fasciae of the perineum and their functions.
  9. Trace the nerve and blood supply to the external genital organs and the muscles of the perineum.
  10. Trace the lymphatic drainage of the perineum.
  11. Trace the continuity of the abdominal peritoneum with that of the pelvic cavity, and identify the peritoneal pouches of the pelvic floor in both sexes.
  12. Describe the relationships of the bladder to other pelvic organs in both sexes.
  13. Describe the normal position and relationships of the organs of the female reproductive tract and the role of each in reproductive processes.
  14. Describe the broad ligament and differentiate its parts.
  15. Identify the ovary and discuss the functional significance of its ligaments.
  16. Demonstrate the uterine tube and its subdivisions.
  17. Identify the uterus and its subdivisions and demonstrate the continuity of its lumen with that of the uterine tubes and the vagina.
  18. Differentiate between the internal and external os of the cervix.
  19. Identify the vagina, and note the angle formed at its junction with the uterus.
  20. Describe the support mechanisms for the uterus which act to prevent uterine prolapse.
  21. Describe the formation of the two sciatic foramina. List the muscles, nerves, and vessels which pass through each.
  22. Describe the general gross features of the breast and its blood supply, innervation, and lymphatic drainage.

Procedure:

1. Review the bony landmarks. (Play movie; View images: N 248, 352, 486, 503, TG 3-04, 3-05, 3-07, 6-03, 6-06A, 6-06B)

Examine the bony pelvis and identify the obturator foramen and groove, the greater sciatic notch (foramen), spine of the ischium, the lesser sciatic notch (foramen), ischial tuberosity. Locate the sacroiliac joint. Review how the sacrotuberal and sacrospinal ligaments help to form the greater and lesser sciatic foramina.

2. Review the bony landmarks. Examine the peritoneal relationships in the pelvis. (Play movie; View images: N 248, 354, 356, 357, 358, 360, 361, 362, 363, 371, 380, 486, TG 5-03,3-04, 6-05A, 6-05B, 6-05CD, 6-05EF, 6-07A, 6-07B, 6-08A, 6-08B, 6-11, 6-13, 6-21A, 6-21B, 6-23, 6-24A, 6-24B)

On the skeleton define the bony landmarks of the perineum: pubic symphysis, pubic arch, inferior ramus of the pubis and the ramus of the ischium (together known as the ischiopubic ramus), the ischial tuberosities, and the coccyx. Define the urogenital triangle and the anal triangle. Note that the two triangles do not lie on the same plane.

Although it is not well seen at this time and will be studied in detail later, understand that the pelvic viscera are supported by the muscles comprising the pelvic diaphragm.

Examine male and female bony pelves and determine different characteristics of each. Note the difference between male and female in the subpubic angle, the angle formed by the pubic arch. Other sex differences in the pelvic skeleton? Now continue with dissection procedures for either male or female, but be sure to review all structures on a cadaver of the opposite sex as well.

Bony structures of the pelvis

Observe the peritoneal relationships in the pelvis and identify the uterus, uterine tubes, and ovaries in the female and rectum in both sexes. Notice how these structures and the associated peritoneum form the rectouterine and vesicouterine pouches in the female and rectovesical pouch in the male.

The peritoneal reflection onto the uterus, uterine tubes, and ovaries from the lateral pelvic wall is called the broad ligament. Observe its three component parts: the mesosalpinx associated with the uterine tubes, the mesovarium associated with the ovary, and the mesometrium contacting the uterus.

3. Examine the external genitalia of the female. (Play movie; View images: N 351, 377, 382, 387A, 387B, 390, 398, TG 6-02, 6-25A, 6-25B, 6-31)

Before proceeding with the midsagittal section of the pelvis below, identify the female external genitalia: vulva, mons pubis, labia majora and their anterior and posterior commissures; labia minora and associated frenulum; clitoris and its glans, and prepuce; vestibule and its vaginal orifice and external urethral meatus.

4. Skin the ischioanal fossa and remove the fat. Identify the sacrotuberal and sacrospinal ligaments and the inferior rectal nerves and vessels. (Play movie; View images: N 353, 357, 358, 359, 377, 379, 380, 381, 395, 402 403, 404, 405, 411, 413, 502, 503, TG 3-07, 3-26, 6-06, 6-15A, 6-15B, 6-15C, 6-23A, 6-23B, 6-24A, 6-24B, 6-26A, 6-26B, 6-28, 6-29A, 6-29B, 6-30A, 6-30B)

Remove the skin from the anal triangle. Care should be taken when skinning around the anus because the external anal sphincter muscle is in contact with the skin. Clean and identify the external anal sphincter.

Using blunt dissection through the fat of the ischioanal (ischiorectal) fossa, locate the inferior rectal vessels and nerves, supplying the external anal sphincter. On the lateral side, follow the walls of the ischioanal fossa and remove all of the fat within the fossa. To do this, identify the inferior border of the gluteus maximus muscle and the ischial tuberosity and follow these surfaces deeply within the ischioanal fossa until the fat wedge is free. Note how gluteus maximus overhangs the ischioanal fossa. Reflect the fibers of gluteus maximus that originate from the sacrotuberal ligament. Define all boundaries of the ischioanal fossa. Note that the lateral wall is the fascia of the obturator internus muscle, and cut the sacrotuberal ligament from its attachment on the ischial tuberosity. Beneath the sacrotuberal ligament, identify the sacrospinal ligament and the greater and lesser sciatic foramina.

5. Identify the pudendal canal and pudendal neurovascular bundle. (Play movie; View images: N 402, 403, 404, 405, 410, 411, 413, 497, 499, 503, TG 3-25A, 3-25B, 3-26, 6-17A, 6-17B, 6-19, 6-29A, 6-29B, 6-30)

Identify the pudendal neurovascular bundle passing around the sacrospinal ligament. Pick up the inferior rectal vessels and nerves, and gently pull toward the midline. This tension will elevate the wall of the pudendal canal so that it may be visualized. Open the canal and identify the pudendal nerve, the internal pudendal artery and veins. Note how far (deep) this canal is from the tip of the ischial tuberosity.

6. Skin the urogenital triangle. Identify the pudendal neurovascular branches. Clean the erectile bodies and reflect them from their attachments on one side. Identify the perineal membrane and sphincter urethrae m. (Play movie; View images: N 265, 344, 357, 377, 379A, 379B, 381, 395, 404, 413, TG 6-08, 6-24, 6-25, 6-29, 6-27, 6-28, 6-29, 6-30, 6-32)

Remove the skin of the perineum from a longitudinal incision along the medial border of the labia majora laterally to the ischiopubic ramus.

The subcutaneous tissue of the perineum consists of a superficial fatty and a deeper membranous layer. Dissect through the fat of the labia majora and locate the posterior labial nerve, arteries and veins (branches of the perineal nerve from pudendal nerve and internal pudendal artery and vein, respectively). Remove the excess fat and reflect the membranous plane laterally to the ischiopubic ramus.

Remove the muscular fascia; dissect and identify the ischiocavernosus and bulbospongiosus muscles. Great care must be taken because the muscles are very thin and delicate. Note specifically the relations of these muscles to the cavernous bodies. Clear the perineal body. Reflect the bulbospongiosus muscle from the perineal body on one side, carefully lifting it from the surface of the vestibular bulb, and noting the manner in which the muscle ends at the base of the shaft of the clitoris. Do you find muscular branches (deep) of the perineal nerves? Look for the greater vestibular glands at the posterior margin of the vestibular bulbs, deep to the bulbospongiosus muscles. Reflect the ischiocavernosus muscle on the same side and expose the crus of the clitoris. Examine the crus and trace the corpus cavernosum clitoridis forward until it unites with the corpus cavernosum of the opposite side to form the shaft of the clitoris. On the dorsum of the shaft of the clitoris, locate the deep dorsal vein, and the dorsal nerves and dorsal arteries of the clitoris. Examine the glans clitoridis.

Cut the crus of the clitoris from the ischiopubic ramus on one side, and free the vestibular bulb on that side from its attachment to the perineal membrane. As you do this, try to identify the deep artery of the clitoris and the artery to the bulb. Source? Crossing between the arcuate pubic ligament and the perineal membrane is the deep dorsal vein of the clitoris, while the dorsal arteries and nerves of the clitoris pass through the anterosuperior portion of the perineal membrane. Source or drainage of each? Section the corpus cavernosum clitoridis and the vestibular bulb, examining the erectile tissue and tunica albuginea.

Now examine the perineal membrane, its extent and attachments. Consider its function. Examine the vagina passing through the membrane, noting its relationship to the membranous urethra and the sphincter urethrae muscle.

Review the lymphatics of the pelvis and perineum.

7. Examine the female genital tract, remove the peritoneum overlying the ovarian vessels. (Play movie; View images: N 360, 362, 369, 370, 371A, 371B, 378, 382A, 382B, 383, 399, 400, 402, 404A, 404B, TG 5-34, 6-08, 6-09A, 6-10, 6-11, 6-12, 6-17, 6-23, 6-29)

On the sagittally-sectioned specimen, trace the peritoneum from the ventral abdominal wall; examining the vesicouterine pouch and its manner of reflection from the bladder to the uterus (what part of uterus?). Trace the peritoneum across the uterus and define the rectouterine pouch. Note peritoneum on the posterior wall of the vagina. From what point does the peritoneum reflect to the rectum? Significance?

Pull the uterus toward the mid-line and define the broad ligament and its parts: mesosalpinx, mesovarium, and mesometrium. Within the broad ligament, locate the ovarian ligament and the round ligament of the uterus. Consider development and continuities. Locate and define the peritoneal fold called the suspensory ligament of the ovary. What does it contain?

Uterine tube: Examine the uterine tube; define the isthmus, ampulla, infundibulum, fimbriae, and ostium. Note continuity with uterus, relations and attachment to ovary.

Hysterosalpingogram

Ovary: Examine the ovary. Consider size, attachments, covering, relations to broad ligament and uterine tube. Slice one of them longitudinally and examine for follicles, etc.

Strip the peritoneum from the suspensory ligament of the ovary on one side and trace the ovarian artery and vein (source?). What is its complete area of distribution? Continue stripping the peritoneum from both surfaces of the broad ligament on the same side as above and locate the uterine artery and veins near its base. Trace to the uterus, noting branches and point of junction at the uterine wall. Locate the ureter (relation to uterine artery); trace it to the bladder and posteriorly to the brim of the pelvis, noting course, relation to peritoneum and blood supply. Trace the round ligament from the uterus (attachment? ) to the deep inguinal ring.

Uterus: Examine the uterus and define its parts: fundus, body, its lumen (cavity) isthmus, cervix, and cervical canal. Note shape, size, and flexure. What structure supports the uterus?

Vagina: Examine the vagina and the structure of its wall. Consider differences between vagina and vaginal vestibule. Examine the intravaginal cervix, the ostium of the uterus, and fornices of the vagina. Note relations to urethra, bladder, and rectum. Significance? Locate relation to pelvic diaphragm and perineal membrane.

Fetus

Explore the female urethra and note length, sphincter muscle, relation to vagina. Note specifically the relation of the orifice to the anterior vaginal wall. Significance? Where the neck of the bladder meets the pelvic diaphragm and posterior side of the pubis, identify the pubovesical ligament. Examine the sphincter urethrae muscle, and the membranous portion of the urethra.

Consider the blood supply and venous drainage of the ovary, uterine tube, uterus, vagina.

8. Remove the skin from the chest wall and examine the breast. (Play movie; View images: N 180, 182, 183, 184, 188, 189, 192, 257, 420, 427, 429, 430, TG 1-17, 2-10A, 2-10B, 2-11A, 2-11B, 2-12, 2-13, 2-15A, 2-15B, 4-02, 4-07, 4-11)

Remove the skin and subcutaneous tissue over the pectoral and anterior deltoid regions, down to about mid-brachium (Fig. 2).

The uppermost incision should directly overlie the clavicle. Along the lateral margin of the sternum, identify anterior cutaneous branches of intercostal nerves. As you approach the anterior axillary line, use blunt dissection to find examples of lateral cutaneous branches of intercostal nerves in the superficial fascia running parallel to the ribs. Where do their anterior and posterior branches distribute? Identify several anterior branches of these nerves as they emerge along the anterior axillary line through the serratus anterior muscle. Observe serratus anterior arising from the anterolateral rib cage and passing backward to insert onto the vertebral border of the scapula.

Mammary gland. Incise through the nipple and areola with horizontal and vertical incisions. Is any pinkish glandular tissue visible? Normally no glandular elements are visible in the male. In the female, examine cut surfaces for lactiferous ducts and sinuses. Try to define a lobe. What are suspensory ligaments? Note attachments and location. Because of age and non-lactating condition of the gland, atrophy may be present and the internal structure hard to discern. It should be understood that in regard to female cadavers, nearly all of them, if not all, are elderly and postmenopausal and consequently many female structures influenced by female hormones will be difficult to demonstrate or identify throughout the body. Consider blood supply, nerve supply and lymphatic drainage. Note the position of the nipple in reference to the intercostal spaces.

Mammogram Breast cancer