Myology

Question 1

Superficial Perineal Muscles

Answer 1

• superficial transverse perineal M.
• ischiocavernosus M.
• bulbospongious M.

Question 2

Superficial Transverse Perineal M. actions

Answer 2

Support fix perineal body, supports abdominopelvic viscera, resists increases in intraab. pressure

Question 3

Superficial transverse perineal m. innervation

Answer 3

Deep perineal N.

Question 4

Ischiocavernosus m. actions

Answer 4

Maintains erection of penis/clitoris by compressing venous drainage and forces blood from crura into body of penis/clitoris

Question 5

Ischiocavernosus m. innervation

Answer 5

Deep perineal N.

Question 6

Bulbospongiosus m. actions

Answer 6

• Support/fix perineal body
• Compresses bulb of penis
• Assists in erection through venous compression
• Expels final drops of urine
• Compresses greater vestibular gland (F)

Question 7

Bulbospongiosus m. innervation

Answer 7

Deep perineal N.

Question 8

What separates urogenital diaphragm from superficial perineal muscles?

Answer 8

Perineal Membrane

Question 9

External Urethral Sphincter m.

Answer 9

Compressor Urethrae m. and urethrovaginal sphincter m.

Question 10

Compressor Urethrae m.

Answer 10

Constricts urethra to maintain urinary continence

- Dorsal nerve of the penis/clitoris

Question 11

Urethrovaginal sphincter m.

Answer 11

Compresses the vagina

- Dorsal nerve of the clitoris

Question 12

Deep Transverse perineal m.

Answer 12

Support/fix perineal body, supports abdominopelvic viscera and resists increases in intrathoracic pressure
- Deep perineal n.

Question 13

How is deep transverse perineal m. described in females?

Answer 13

Smooth muscular mass along posterior edge of perineal membrane

Question 14

External Anal Sphincter m.

Answer 14

Constricts the anal canal during peristalsis, resists defecation, supports/fixes perineal body
- Inferior rectal n.

Question 15

Internal Anal Sphincter m.

Answer 15

involuntary sphincter surrounding 2/3 the anal canal

- Parasympathetic

Question 16

Pelvic diaphragm muscles

Answer 16

• Levator ani ms. and coccygeus m.

- Superficial fascia contain pubovesicalis m. (from pubis to urinary bladder) and rectovesicalis m. (rectum to bladder)

Question 17

Levator ani ms.

Answer 17

Puborectalis m., pubococcygeus m., iliococcygeus m.

Question 18

Puborectalis m. actions

Answer 18

Maintains anal flexure, supports pelvic viscera, resists increases in intraabdominal P.

Question 19

Puborectalis m. innervation

Answer 19

Nerve to the levator ani m. (S4), inferior rectal n., branches of coccygeal plexus

Question 20

Pubococcygeus m. actions

Answer 20

Supports pelvic viscera, resists increases in intraabdominal P.

Question 21

Pubococcygeus m. innervation

Answer 21

Nerve to the levator ani m. (S4), inferior rectal n., branches of coccygeal plexus

Question 22

Pubococcygeus m. extensions

Answer 22

Levator prostatae m., pubovaginalis m., puboperinealis m., and puboanalis m.

Question 23

Iliococcygeus m. actions

Answer 23

Supports pelvic viscera and resists increases in intraabdominal pressure

Question 24

Iliococcygeus m. innervation

Answer 24

Nerve to the levator ani m. (S4), inferior rectal n., branches of coccygeal plexus

Question 25

Coccygeus m.

Answer 25

Supports pelvic viscera, flexes coccyx

- Nerve to coccygeus (S4/5) and branches of coccygeal plexus

Question 26

Lateral pelvic wall muscles

Answer 26

Obturator internus m. and piriformis m.

Question 27

Obturator internus m.

Answer 27

Rotate thigh laterally, stabilize femoral head in acetabulum

- Nerve to obturator internus m.

Question 28

Piriformis m.

Answer 28

Rotate thigh laterally, abduct thigh, stabilize femoral head in acetabulum
- Nerve to piriformis m.

Question 29

Perineal Body

Answer 29

Irregular fibromuscular mass @ midline between anal canal and perineal membrane
- Attachment point for bulbospongiosus m., external anal sphincter m., superficial transverse perineal m. and deep transverse perineal m.