MODULE 2:

OBJECTIVES:

2.1 Identify the muscles of the pelvis, including the pelvic diaphragm and its components. Identify the urogenital diaphragm and its components. Indicate the relationship of the pelvic diaphragm and the urogenital diaphragm to the genitourinary tracts in the female.

2.2 Identify the rectum, anus, and the anal sphincters. Trace the course of the pudendal nerve and its branches to all structures in the perineum.

READINGS:

Pages 450-462,502-515 : See Green Highlighted sections for clinical correlation.

SECTRA TABLE WORK:

    Starting from the basic pelvis from Module 1

  1. Select Pelvis

  2. Add Psoas

    3. The psoas major joins the iliacus in the pelvis, and passes under the inguinal ligament. Since they share an insertion on the lesser trochanter of the femur, in this area the two muscles are listed as the iliopsoas muscle.

  3. Add Iliopsoas

  4. Rotate the Pelvis upward and visualize the pelvis from below.

  5. Add Levator ani which is composed of the three muscles.

    6. Pubococcygeus muscle

    Puborectalis muscle

    Iliococcygeus muscle

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  6. Add Coccygeus

    7. Review the functions of the muscles in this area in the GI Block reading SB and Colon Part 1 - Section B - Subsections e and f. Also read Gray's Anatomy page 454 Green box 'Defecation'

  7. Add Internal anal sphincter

  8. Rotate Pelvis to see where the levator ani joins the obturator internus. This is called the tendinous arch and deliniates the laternal aspect pelvis from the pelvic floor.

  9. Rotate the Pelvis to see the perineum.

    10. Draw an imaginary line between the ischial tuberosities. This separates the posterior muscular pelvic diaphragm, which controls defecation, from the urogenital triangle which contains the vaginal and the urethral openings.

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    What are the landmarks that deliniate the urogenital triangle?

    Although we cannot see this membrane on our cadaver its components are visable and include:

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  10. Add Perineal body

  11. Add Superficial transverse perineal muscle.

  12. Add Vaginal orifice

  13. Add Urethral sphincter

    14. On top of this membrane sits the erectile tissues of the urogenital triangle.

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    The erectile tissues are covered by the following muscles:

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  14. Add Ischiocavernosus muscles which covers the corpus cavernosi. The corpus cavernosi joins at the midline to form the glans clitoris

  15. Add Bulbospongiosus muscles which covers and surrounds the remaining components of the vestibule.

    16. Note that the urethral orifice is just posterior to the glans clitoris. This will serve as a landmark when doing a urinary catheterization of a female.

  16. Add External anal sphincter

    17. Discuss the three components of the external anal sphincter.

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  17. Add Pudendal nerve and trace its path from the sacrum to the pelvic diaphragm.

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    Discuss the three divisions of the pudenal nerve.

  18. Inferior rectal nerve

  19. Perineal nerve

  20. Dorsal nerve of the clitoris

    21. If you were injecting the pudendal nerve for pain control, where would the needle be placed?

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