Anatomy of the Perineum 1

Question 1

Define the perineum.

Answer 1

A diamond-shaped region at the pelvic outlet below the pelvic diaphragm, which contains the urogenital and anal canal openings

Question 2

What are the divisions of the perineum?

Answer 2

• Urogenital trianble (anterior)
• Anal triangle (posterior)

Question 3

What are the boundaries of the perineum?

Answer 3

• Pubic symphisis
• Ischial tuberosities
• Coccyx
• Superior extent is pelvic diaphragm
• Lateral walls are obturator internus and ischiopubic rami

Question 4

What are the boundaries and structures in the anal triangle?

Answer 4

• Same in both sexes
• Posterior to a line between the ischial tuberosities
• Contains the following:
  
  • anus
  • anorectal flexure
  • anorectal “sling” of puborectalis
  • anal sphincters

Question 5

Where is the ischio-anal fossa? What structures are found in this fossa?

Answer 5

• Lateral to anal sphincter and cone of pelvic diaphragm
• Contains fat and pudendal canal (in obturator internus fascia)
  
  • contains pudendal nerve and vessels
    
    • Inferior rectal branches traverse fossa
• Left and right fossae communicate posteriort