Myo

Question 1

Describe the perineal body

Answer 1

Irregular fibromuscular mass in the midline between anal canal and perineal membrane

Question 2

What is the irregular fibromuscular mass in midline between anal canal and perineal membrane?

Answer 2

perineal body

Question 3

What does the perineal body contain, and what muscles is it an attachment point for?

Answer 3

Collagenous and elastic fibers

Bulbospongiosus m., external anal sphincter m., superficial transverse perineal m., deep transverse perineal m.

Question 4

What is the attachment point for bulbospongiosus m., external anal sphincter m., superficial transverse perineal m., and deep transverse perineal m.?

Answer 4

Perineal body

Question 5

What is sometimes classified as a central tendon of pelvic and urogenital diaphragms?

Answer 5

Perineal body

Question 6

What are the origin and insertion sites for the superficial transverse perineal m.?

Answer 6

Origin: ischiopubic ramus and ischial tuberosity
Insertion: Perineal body

Question 7

What originates on the ischiopubic ramus and ischial tuberosity and inserts on perineal body?

Answer 7

Superficial transverse perineal m.

Question 8

What is the action of the superficial transverse perineal m?

Answer 8

Supports and fixes perineal body
Supports abdominopelvic viscera
Resists increases in intraabdominal pressure

Question 9

What muscles supports/fixes perineal body, supports abdominopelvic viscera, and resists increases in intraabdominal pressure?

Answer 9

Superficial transverse perineal m.

Deep transverse perineal m (Male)

Question 10

What innervates the superficial transverse perineal m?

Answer 10

Deep perineal nerve

Question 11

What are the origin and insertion sites for ischiocavernosus m?

Answer 11

O: ischiopubic ramus and ischial tuberosity
I: Perineal membrane medial to Crura
Medial aspect of Crus of penis (male) or clitoris (female)

Question 12

What muscle originates on ishciopubic ramus and ischial tuberosity and inserts on medial aspect of crus of penis/clitoris and perineal membrane medial to crura?

Answer 12

Ischiocavernosus m

Question 13

What is the action of the ischiocavernosus m?

Answer 13

Maintain erection of penis or clitoris by compressing venous drainage, forcing blood from crura into body of penis or clitoris

Question 14

What muscle maintains erection of penis/clitoris by compressing venous drainage, forcing blood from crura into body of penis/clitoris?

Answer 14

Ischiocavernosus m.

Question 15

What innervates ischiocavernosus m?

Answer 15

Deep perineal n.

Question 16

What are the origin and insertion sites for bulbospongiosus m.?

Answer 16

O: median raphe, ventral bulb of penis and perineal body (male), perineal body (female)
I: perineal membrane, fascia of bulb of penis and corpus spongiosum and corpora cavernossa of penis (male); fascia of bulb of vestibule of vagina, pubic arch and fascia of corpora cavernosa of clitoris (female)

Question 17

What are the superficial perineal muscles?

Answer 17

Superficial transverse perineal m.
Ischiocavernosus m.
Bulbospongiosus m.

Question 18

What muscle originates on the median raphe, ventral bulb of penis and perineal body (male), perineal body (female) and inserts on perineal membrane, fascia of bulb of penis and corpus spongiosum and corpora cavernosa of penis; fasia of bulb of vestibule of vagina, pubic arch and fascia of corpora cavernosa of clitoris?

Answer 18

Bulbospongiosus m

Question 19

What is the action of the bulbospongiosus m.?

Answer 19

Support and fix perinal body
Compress bulb of penis, assist erection by compressing venous drainage, forcing blood form root of penis to body of penis, expels final drops of urine/semen from urethra
Compress vaginal orifice, assist in erection of bulbs of vestibule of vagina and compress greater vestibular gland

Question 20

What muscle supports/fixes perineal body, compresses bulb of penis, assists erection by compressing venous drainage (forcing blood from root of penis to body of penis), expels final drops of urine/semen form urethra, compresses vaginal orifice, assists in erection of bulbs of vestibule of vagina, and compresses greater vestibular gland?

Answer 20

Bulbospongiosus m

Question 21

What innervates the bulbospongiosus m?

Answer 21

Deep perineal n

Question 22

Which superficial perineal muscle does not originate on ischiopubic ramus and ischial tuberosity?

Answer 22

Bulbospongiosus m

Question 23

What does the deep perineal nerve innervate?

Answer 23

Superficial transverse perineal m
Ischiocavernosus m
Bulbospongiosus m
Deep transverse perineal m (male)

Question 24

Describe the urogenital diaphragm

Answer 24

Muscle layer deep to and separated from superficial perineal muscles by perineal membrane.
However, may contain elements of superficial perineal muscles and perineal membrane

Question 25

What muscle layer is deep to and separated from superficial perineal muscles by perineal membrane?

Answer 25

Urogenital diaphragm

Question 26

What muscles make up urogenital diaphragm?

Answer 26

External urethral sphincter m | Deep transverse perineal m

Question 27

External urethral sphincter m. And deep transverse perineal m. Make up what layer?

Answer 27

Urogenital diaphragm

Question 28

What are the origin and insertion sites for external urethral sphincter m?

Answer 28

O/I: Surrounds urethra

Question 29

What muscle surrounds the urethra?

Answer 29

External urethral sphincter m

Question 30

What is the action of the external urethral sphincter m?

Answer 30

Constricts urethra, maintaining urinary continence

Question 31

What muscles constricts the urethra, maintaining urinary continence?

Answer 31

External urethral sphincter m | Compressor urethrae m

Question 32

What innervates the external urethral sphincter m?

Answer 32

Dorsal nerve of penis/clitoris

Question 33

Where is the compressor urethrae m? O/I?

Answer 33

Extends laterally from external urethral sphincter O: Ischiopubic ramus and ischial tuberosity I: Median raphe and urethra via external urethral sphincter m.

Question 34

What muscle originates from ischiopubic ramus and ischial tuberosity and inserts on median raphe and urethra via external urethral sphincter m?

Answer 34

Compressor urethrae m

Question 35

What innervates the compressor urethrae m?

Answer 35

Dorsal nerve of penis/clitoris

Question 36

What is the urethrovaginal sphincter m?

Answer 36

In female | Slips of external urethral sphincter m that also surround vagina

Question 37

What muscle is slips of external urethral sphincter m that also surround vagina?

Answer 37

Urethrovaginal sphincter m

Question 38

What are the origin and insertion sites of urethrovaginal sphincter m?

Answer 38

O: ischiopubic ramus and ischial tuberosity I: external wall of vagina

Question 39

What muscle originates on ischiopubic ramus and ischial tuberosity and inserts on external wall of vagina?

Answer 39

Urethrovaginal sphincter m

Question 40

What is the action of urethrovaginal sphincter m?

Answer 40

Compresses vagina

Question 41

What muscle compresses the vagina?

Answer 41

Urethrovaginal sphincter m

Question 42

What innervates urethrovaginal sphincter m?

Answer 42

Dorsal nerve of clitoris

Question 43

What does the dorsal nerve of the penis/clitoris innervate?

Answer 43

External urethral sphincter m Compressor urethrae m Urethrovaginal sphincter m

Question 44

What are the origin and insertion sites of the deep transverse perineal m (male)?

Answer 44

O: ischiopubic ramus and ischial tuberosity I: Median raphe, perineal body, external anal sphincter

Question 45

What muscle originates on ischiopubic ramus and ischial tuberosity and inserts median raphe, perineal body, and external anal sphincter?

Answer 45

Deep transverse perineal muscle (Males)

Question 46

What is the action of the deep transverse perineal m?

Answer 46

Support and fix perineal body Support abdominopelvic viscera Resist increases in intraabdominal pressure

Question 47

What innervates the deep transverse perineal m?

Answer 47

Deep perineal nerve

Question 48

What is the deep transverse perineal muscle in the female?

Answer 48

Smooth muscular mass along posterior edge of perineal membrane

Question 49

What are the anal muscles?

Answer 49

External anal sphincter m | Internal anal sphincter m

Question 50

What are the origin and insertion sites for external anal sphincter m?

Answer 50

O: skin and fascia surrounding anus and anococcygeal body I: perineal body

Question 51

What muscle inserts on skin and fascia surrounding anus and anococcygeal body and inserts on perineal body?

Answer 51

External anal sphincter m

Question 52

What is the action of the external anal sphincter m?

Answer 52

Constricts anal canal during peristalsis Resists defecation Supports/fixes perineal body

Question 53

What muscle constricts anal canal during peristalsis, resists defecation, and supports/fixes perineal body?

Answer 53

External anal sphincter m

Question 54

What innervates the external anal sphincter m?

Answer 54

Inferior rectal nerve

Question 55

What is the internal anal sphincter m?

Answer 55

Involuntary sphincter surrounding superior 2/3 of anal canal | Thickening of circular muscular layer

Question 56

What muscle is a thickening of circular muscular layer around superior 2/3 of anal canal?

Answer 56

Internal anal sphincter m

Question 57

What innervates the internal anal sphincter m?

Answer 57

Parasympathetic fivers from pelvic splanchnic nerves

Question 58

What muscles make up the pelvic diaphragm?

Answer 58

Levator ani ms (puborectalis m., pubococcygeus m., iliococcygeus m) Coccygeus m

Question 59

The superficial fascia of the pelvic diaphragm also contains slips of muscles that insert onto urinary bladder. What are these?

Answer 59

Pubovesicalis m | Rectovesicalis m

Question 60

What are the levator ani ms?

Answer 60

Puborectalis m Pubococcygeus m Iliococcygeus m,

Question 61

Describe the puborectalis m

Answer 61

Thick, narrow, medial part of levator ani

Question 62

What muscle is the thick, narrow, medial most part of levator ani?

Answer 62

Puborectalis m.

Question 63

What are the origin and insertion sites for puborectalis m?

Answer 63

O: posterior aspect of pubic body I: external wall of rectum and anal canal

Question 64

What muscle originates from posterior aspect of pubic body and inserts on external wall of rectum and anal canal?

Answer 64

Puborectalis m.

Question 65

What is the action of the puborectalis m?

Answer 65

Maintain anorectal flexure Support pelvic viscera Resist increases in intraabdominal pressure

Question 66

What muscle maintains anorectal flexure, supports pelvic viscera, and resists increase in intraabdominal pressure?

Answer 66

Puborectalis m.

Question 67

What innervates puborectalis m?

Answer 67

Nerve to levator ani m. (S4) Inferior rectal N Branches of coccygeal plexus

Question 68

Describe pubococcygeus m

Answer 68

Thin, wide, main part of levator ani

Question 69

What muscle is the thin, wide, main part of levator ani?

Answer 69

Pubococcygeus m

Question 70

What are the origin and insertion sites for pubococcygeus m?

Answer 70

O: posterior aspect of of pubic body and anterior most part of tendinous arch of obturator fascia I: Coccyx, anococcygeal body, contralateral pubococcygeus m

Question 71

What muscle originates on posterior aspect of pubic body and anterior most part of tendinous arch of obturator fascia and inserts on coccyx, anococcygeal body, and contralateral pubococcygeus m?

Answer 71

Pubococcygeus m

Question 72

What is the action of the pubococcygeus m?

Answer 72

Supports pelvic viscera | Resists increases in intraabdominal pressure

Question 73

What muscles support pelvic viscera and resist increases in intraabdominal pressure?

Answer 73

Pubococcygeus m. | Iliococcygeus m

Question 74

What innervates pubococcygeus m?

Answer 74

Nerve to levator ani (S4) Inferior rectal n Branches of coccygeal plexus

Question 75

The pubococcygeus m. Prodcues several small slips of muscle that extend to nearby structures, all sharing similar action and innervation as pubococcygeus m. What are these muscles?

Answer 75

``` Levator prostate m (male) Pubovaginalis m (female) Puboperinealis m (both) Puboanalis m (both) ```

Question 76

Describe iliococcygeus m

Answer 76

Posterior, thin, poorly developed part of levator ani

Question 77

What muscle is posterior, thin, poorly developed part of levator ani?

Answer 77

Iliococcygeus m

Question 78

What are the origin and insertion sites for iliococcygeus m?

Answer 78

O: Posterior part of tendinous arch of obturator fascia and ischial spine I: coccyx and anococcygeal body

Question 79

What muscle originates from posterior part of tendinous arch of obturator fascia and ischial spine and inserts on coccyx and anococcygeal body?

Answer 79

Iliococcygeus m

Question 80

What is the action of the iliococcygeus m?

Answer 80

Supports pelvic viscera | Resists increases in intraabdominal pressure

Question 81

What innervates iliococcygeus m?

Answer 81

Nerve to levator ani m (S4) Inferior rectal n Branches of coccygeal plexus

Question 82

What are the origin and insertion sites for coccygeus m?

Answer 82

O: ischial spine I: inferior sacrum and coccyx

Question 83

What muscle originates on ischial spine and inserts on inferior sacrum and coccyx?

Answer 83

Coccygeus m

Question 84

What is the action of coccygeus m?

Answer 84

Support pelvic viscera | Flexes coccyx

Question 85

What muscle supports pelvic viscera and flexes coccyx?

Answer 85

Coccygeus m

Question 86

/What innervates coccygeus m?

Answer 86

Nerve to coccygeus (S4,5) | Branches of coccygeal plexus

Question 87

What are the lateral pelvic wall muscles?

Answer 87

Obturator internus m | Piriformis m

Question 88

What are the origin and insertion sites for obturator internus m?

Answer 88

O: Pelvic surfaces of ilium and ischium and obturator membrane I: Greater trochanter of femur

Question 89

What muscles originates on pelvic surfaces of ilium, ischium, and obturator membrane and inserts on greater trochanter of femur?

Answer 89

Obturator internus m

Question 90

What is the action of the obturator internus m?

Answer 90

Rotate thigh laterally | Stabilize femoral head in acetabulum

Question 91

What muscle rotates thigh laterally and stabilizes the femoral head in acetabulum?

Answer 91

Obturator internus m

Question 92

What nerve innervates obturator internus m?

Answer 92

Nerve to obturator internus m

Question 93

What are the origin and insertion sites for piriformis m?

Answer 93

O: Pelvic surface sacral segments S2-S4, greater sciatic notch, and sacrotuberour ligament I: greater trochanter of femur

Question 94

What muscle originates on pelvic surface sacral segments S2-S4, greater sciatic notch, and sacrotuberous ligament and inserts on greater trochanter of femur?

Answer 94

Piriformis m

Question 95

What are the actions of the piriformis m?

Answer 95

Rotate thigh laterally Abduct thigh Stabilize femoral head in acetabulum

Question 96

what muscle rotates thigh laterally, abducts thigh, and stabilizes femoral head in acetabulum?

Answer 96

Piriformis m

Question 97

What innervates the piriformis m?

Answer 97

Nerve to piriformis m