Pelvic and Perineal Myology

Question 1

What is the name of the fibromuscular mass in the midline between the Anal Canal and the Perineal Membrane? It acts as a muscle attachment site for many of the muscles in the pelvic floor.

Answer 1

Perineal Body

Question 2

List the three muscles that are part of the Superficial Perineal Muscles.

Answer 2

1. Superficial Transverse Perineal M.
2. Ischiocavernosus M.
3. Bulbospongiosus M.

Question 3

Which Nerve innervates the Superficial Perineal Muscles?

Answer 3

Deep Perineal Nerve

Question 4

What is the function of the Superficial Perineal Muscles?

Answer 4

Compress the venous drainage and maintain erect erectile tissue

Question 5

List the two muscles that are in the Urogenital Diaphragm.

Answer 5

1. External Urethral Sphincter M.

2. Deep Transverse Perineal M.

Question 6

Which nerve innervates the Deep Transverse Perineal N.?

Answer 6

Deep Perineal N.

Question 7

Which nerve innervates the External Urethral Sphincter M.?

Answer 7

Dorsal Nerve of the Penis or Clitoris.

Question 8

In the female, what are the two parts that make up the external urethral sphincter muscle?

Answer 8

1. Compressor Urethrae M.

2. Urethrovaginal Sphincter M. (Anchors the muscle to the vagina)

Question 9

What is the big difference in the structure of the Deep Transverse Perineal M. in males and females?

Answer 9

Males - Skeletal Muscle

Females - Smooth Muscle

Question 10

Name the two Anal Muscles

Answer 10

1. External Anal Sphincter M.

2. Internal Anal Sphincter M.

Question 11

What is the innervation for the external anal sphincter m.?

Answer 11

Inferior Rectal N.

Question 12

What is the innervation for the internal anal sphincter?

Answer 12

Parasympathetic fibers from Pelvic Splanchnic Nerves (smooth muscle)

Question 13

What are the four muscles that make up the Pelvic Diaphragm?

Answer 13

1. Coccygeus M.
2. Puborectalis M.
3. Pubococcygeus M.
4. Iliococcygeus M.

Question 14

What are the components of the Levator Ani Ms.?

Answer 14

1. Puborectalis M.
2. Pubococcygeus M.
3. Iliococcygeus M.

Question 15

What is the innervation of the Levator Ani Ms.?

Answer 15

Nerve to Levator Ani M. (S4), Inferior Rectal N., and Branches of the coccygeal Plexus

Question 16

What is the innervation of the Coccygeus M.?

Answer 16

Nerve to the Coccygeus (S4-S5) and branches of the coccygeal plexus

Question 17

Which muscle maintains the Anorectal Flexure?

Answer 17

Puborectalis M.

Question 18

What is the overall function of the Levator Ani Ms.?

Answer 18

Support Pelvic Viscera and resist an increase in intra-abdominal pressure

Question 19

Which muscle is on top of the sacrospinous ligament?

Answer 19

Coccygeus M.

Question 20

List the four muscles that are coming off of the Pubococcygeus M.

Answer 20

1. Levator Prostate M. (Male)
2. Pubovaginalis M. (Female)
3. Puboperinealis M.
4. Puboanalis M.

Question 21

What are the two muscles that are considered Lateral Pelvic Wall Muscles?

Answer 21

1. Obturator Inturnus M.

2. Piriformis M.

Question 22

What is the innervation for the Obturator Internus M.?

Answer 22

Nerve to Obturator Internus M.

Question 23

What is the innervation for the Piriformis M.?

Answer 23

Nerve to Piriformis M.