Perineum (Lab Manual)

Question 1

What are the boundaries of the Perineum?

Answer 1

• Anterior: Pubic Symphysis
• Anteriolateral: Ischiopubic Rami
• Posteriolateral: Sacrotuberous Ligaments
• Posterior: Coccyx

Question 2

What 4 things are contained in the anal triangle?

Answer 2

1. anal canal
2. anus
3. Pudendal Canal
4. Ischoanal Fossae

Question 3

What are the boundaries of the ischioanal fossa?

Answer 3

• Base: Skin and Connective tissue
• Superior Medial Wall: Pelvic Diaphragm (LEVATOR ANI, EXTERNAL ANAL SPHINCTER)
• Lateral: Obturator Internus
• Anteriorly: Anterior Recess
• Posteriorly: Sacrotuberous Ligament and Gluteus Maximus

Question 4

What vessels and/or nerves pass from lateral to medial across each ischioanal fossa?

Answer 4

Inferior rectal n. a. v.

Question 5

What are the anterior and posterior attachments of the external anal sphincter?

Answer 5

• Anterior: Perineal Body

- Posterior: Coccyx

Question 6

What is the nerve and arterial supply to the external anal sphincter?

Answer 6

Nerve: Inferior rectal n.

Artery and Vein: Inferior rectal a. and v.

Question 7

What canal is formed on the medial surface of obturator internus, deep to the sacrotuberous ligament?

Answer 7

pudendal canal

Question 8

What are the contents of the pudendal canal?

Answer 8

• Pudendal n.

- Internal Pudendal v.

Question 9

What supplies the primary motor and sensory innervation to the urogenital and anal triangles?

Answer 9

• Pudendal a.

Question 10

What are the 3 divisions of the pudendal n. and where does it divide?

Answer 10

• Perineal n.
• Dorsal n. of Penis or Clitoris
• Inferior rectal n.

Divides as it crosses the ischial spine

Question 11

How does the perineal n. enter the superficial space?

Answer 11

Passes superiorly to the urogenital diaphragm

Question 12

What nerve gives rise to the posterior labial/scrotal nn and what do these nn. do?

Answer 12

• Perineal n. gives rise to Posterior labial/scrotal nn.

- Sensory from the dorsal scrotum/labia

Question 13

What does the perineal n. innervate?

Answer 13

• motor innervation of ALL muscles in the perineum

- Sensory innervation to the back of the scrotum/labia

Question 14

What is the most lateral of the 3 nn. given of by the perienal n. and what is its course?

Answer 14

• Dorsal n. of the penis/clitoris
• lateral wall of the ischioanal fossa in obt. fascia, enters DEEP space by PIERCEING the posterior border of the UG diaphragm.