1. Lab 21: Perineum/External Genitalia

2. Bulbospongiosus muscle

3. Ischiocavernosus muscle

4. Superficial Transverse Perineus

5. Superficial Transverse Perineus

6. Perineal Membrane (Female)

7. Perineal Membrane (Male)

8. Perineal Body

9. Urogenital Diaphragm

10. UGD

11. UGD

12. Urogenital triangle

13. Colle’s Fascia (Superficial Perineal Fascia)

14. Superficial Perineal Space

15. Ischioanal Fossa (male)

16. Ischioanal Fossa (female)

17. Pudendal Canal (atlas view p. 217)

18. Pudendal Canal

19. Corpus cavernosum

20. Corpus spongiosum

21. Corpus spongiosum

22. Suspensory Ligament of Penis

23. Deep Fascia of Penis (Buck’s Fascia)

24. Buck’s fascia

25. Buck’s Fascia

26. Perineal Fascia

27. Tunica albuginea

28. Crus of Penis

29. Left crus of penis

30. Bulb of Penis

31. Bulb of penis

32. Perineal membrane

33. Mons pubis

34. Clitoris

35. Glans clitoris

36. Glans clitoris

37. Clitoris

38. Body of Clitoris

39. Prepuce of clitoris

40. Labia majora

41. Labia majora

42. Labia minora

43. Labia minora

44. vestibule

45. Female Urethral Orifice
Description:
• External orifice of urinary tract
Function:
• Male: discharge of urine and semen
• Female: discharge of urine

46. Crus of Clitoris Description:
• Paired, erectile body attached to ischiopubic ramus
• Becomes corpus cavernosum in body of clitoris
• Covered by ischiocavernosus muscle
Function:
• Engorged with blood during sexual response

47. Vestibular Bulb Location: • Perineum (urogenital triangle)
Description:
• Paired erectile bodies
• Covered by bulbospongiosus muscle
Function:
• Engorges with blood during sexual response

48. Greater Vestibular Gland
Location:
• Perineum (urogenital triangle)
• Lateral to vaginal opening
Description:
• Paired, mucus-producing gland
• Duct opens into vestibule
Function:
• Lubrication of vaginal opening, especially during sexual response
Also known as:
• Bartholin's gland

49. Perineal Membrane Location: • Perineum (urogenital triangle)
Description:
• Sheet of deep fascia
• Stretches across pubic arch
• Pierced by urethra (both sexes) and vagina
Function:
• Forms part of pelvic floor
• Forms boundary between superficial and deep parts of urogenital triangle
Also known as:
• Inferior fascia of urogenital diaphragm

50. Perineal Body Location: • Perineum (midline)
• Between anus and bulb of penis/posterior wall of vagina
Description:
• Subcutaneous collection of fibrous and muscular tissue
Function:
• Supports pelvic viscera
• Provides attachment for several perineal muscles (superficial and deep transverse perineal muscles, external anal sphincter, and bulbospongiosus muscle)
Comment:
• In female, may be incised surgically (episiotomy) to prevent tearing of perineal tissues during vaginal delivery

51. Internal Pudendal Artery
Origin:
• Internal iliac
Course:
• Exits pelvis via greater sciatic foramen
• Exits gluteal region via lesser sciatic foramen
• Lies in lateral wall of ischio-anal fossa
• Courses anteriorly to external genitalia
Distribution:
• Anal canal
• External genitalia (both sexes)
Branches:
• Inferior rectal
• Perineal
• Dorsal artery of penis/clitoris
• Deep artery of penis/clitoris
Comment:
• Does not supply testes

52. Inferior Rectal Artery
Origin:
• Internal pudendal
Course:
• Crosses medially through adipose tissue of ischio-anal fossa
Distribution:
• Anal canal (muscles and lining)
• Perianal skin
Comment:
• Anastomoses with middle and superior rectal arteries, and with contralateral inferior rectal artery

53. Perineal
The perineal artery (superficial perineal artery) arises from the internal pudendal artery, and turns upward, crossing either over or under theTransversus perinæi superficialis, and runs forward, parallel to the pubic arch, in the interspace between the Bulbocavernosus and Ischiocavernosus, both of which it supplies, and finally divides into several posterior scrotal branches which are distributed to the skin and dartos tunic of the scrotum

54. Dorsal Artery of Penis
• Paired arteries on dorsal surface course length of body of penis
Supplies skin of penis

55. Deep Artery of Penis
The deep artery of the penis (artery to the corpus cavernosum), one of the terminal branches of the internal pudendal, pierces the inferior fascia, and, entering the crus penis obliquely, runs forward in the center of the corpus cavernosum penis, to which its branches are distributed

56. Pudendal Nerve
Ventral rami of S2-4 spinal nerves

57. Inferior Rectal Ventral rami of S2-4 spinal nerve Motor:
• External anal sphincter
General sensation:
• Lining of lower part of anal canal (i.e., inferior to pectinate line)
• Perianal skin

58. Perineal (superficial and deep nerves)

59. Posterior Scrotal/Labial Nerve
They are branches of the perineal nerve, which is itself is a branch of the pudendal nerve. The pudendal nerve arises from spinal roots S2 through S4, travels through the pudendal canal on the fascia of the obturator internus muscle, and gives off the perineal nerve in the perineum. The major branch of the perineal nerve is the posterior scrotal/posterior labial.

60. Dorsal Nerve of Penis/Clitoris
Contributions:
• Ventral rami of S2-4 spinal nerves
Comment:
• Terminal branch of pudendal nerve
• Forms dense network of sensory nerve endings (especially in glans) important in sexual response