Pelvic Floor Muscles

Question 1

BULBOSPONGIOSUS

Answer 1

ORIGIN
Perineal body (and midline raphe over corpus spongiosum in male)

INSERTION
Superficial perineal membrane and dorsal penile/clitoral aponeurosis

ACTION
Male:aids emptying of urine and ejaculate from urethra. Female: closes vaginal introitus

NERVE
Perineal branch of pudendal nerve (S2, 3, 4)

Question 2

CREMASTER

Answer 2

ORIGIN
Lower border of internal oblique and transversus abdominis in inguinal canal

INSERTION
Loops around spermatic cord and tunica vaginalis and some fibers return to attach to pubic tubercle

ACTION
Retracts testis

NERVE
Genital branch (L2) of genitofemoral nerve (L1, 2)

Question 3

DARTOS

Answer 3

ORIGIN
Subcutaneous tissue of scrotum, superficial to superficial fascia (Colles)

INSERTION
Skin and midline fibrous septum of scrotum

ACTION
Corrugates scrotal skin

NERVE
Sympathetic fibers from genital branch (L2) of genitofemoral nerve (L1, 2)

Question 4

DEEP TRANSVERSE PERINEI

Answer 4

ORIGIN
Medial aspect of ischiopubic ramus and body of ischium

INSERTION
Midline raphe and perineal body

ACTION
Fixes perineal body and supports pelvic viscera

NERVE
Perineal branch of pudendal nerve (S2, 3, 4)

Question 5

GEMELLUS INFERIOR

Answer 5

ORIGIN
Upper border of ischial tuberosity

INSERTION
Middle part of medial aspect of greater trochanter of femur

ACTION
laterally rotates and stabilizes hip

NERVE
Nerve to quadratus femoris (L4, 5, S1)

Question 6

GEMELLUS SUPERIOR

Answer 6

ORIGIN
Spine of ischium

INSERTION
Middle part of medial aspect of greater trochanter of femur

ACTION
laterally rotates and stabilizes hip

NERVE
Nerve to obturator internus (L5, S1, 2)

Question 7

GLUTEUS MAXIMUS

Answer 7

ORIGIN
Outer surface of ilium behind posterior gluteal line and posterior third of iliac crest lumbar fascia, lateral mass of sacrum, sacrotuberous ligament and coccyx

INSERTION
Deepest quarter into gluteal tuberosity of femur, remaining three quarters into iliotibial tract (anterior surface of lateral condyle of tibia)

ACTION
Extends and laterally rotates hip. Maintains knee extended via iliotibial tract

NERVE
Inferior gluteal nerve (L5, S1,2)

Question 8

GLUTEUS MEDIUS

Answer 8

ORIGIN
Outer surface of ilium between posterior and middle gluteal lines

INSERTION
Posterolateral surface of greater trocanter of femur

ACTION
Abducts and medially rotates hip. Tilts pelvis on walking

NERVE
Superior gluteal nerve (L4,5,S1)

Question 9

GLUTEUS MINIMUS

Answer 9

ORIGIN
Outer surface of ilium between middle and inferior gluteal lines

INSERTION
Anterior surface of greater trochanter of femur

ACTION
Abducts and medially rotates hip. Tilts pelvis on walking.

NERVE
Superior gluteal nerve (L4, 5, S1)

Question 10

ISCHIOCAVERNOSUS

Answer 10

ORIGIN
Medial aspect of ischium and ischiopubic ramus

INSERTION
Inferolateral aponeurosis over crura of penis /clitoris

ACTION
Stabilizes erect penis

NERVE
Perineal branch of pudendal nerve (S2, 3, 4 )

Question 11

COCCYGEUS

Answer 11

ORIGIN
Sacrospinous ligament

INSERTION
Anococcygeal body and coccyx

ACTION
Supports pelvic viscera

NERVE
anterior primary rami (perineal branches) of S4, 5

Question 12

ILIOCOCCYGEUS

Answer 12

ORIGIN
Posterior half of fascial line over obturator internus and ischial spine

INSERTION
Anococcygeal body

ACTION
Supports pelvic viscera

NERVE
Anterior primary rami (perineal branches) of S3, 4

Question 13

PUBOCOCCYGEUS

Answer 13

ORIGIN
Posterior surface of pubis and anterior half of fascial line over obturator internus

INSERTION
Anococcygeal body

ACTION
Supports pelvic viscera

NERVE
Anterior primary rami (perineal branches) of S3, 4

Question 14

PUBORECTALIS

Answer 14

ORIGIN
Posterior surface of pubis

INSERTION
Midline sling posterior to rectum

ACTION
Supports and aids continence of rectum by maintaining anorectal angle

NERVE
Anterior primary rami (perineal branches) of S3, 4

Question 15

PUBOVAGINALIS

Answer 15

ORIGIN
Posterior surface of pubis

INSERTION
Midline raphe posterior to vagina /prostate

ACTION
Supports anterior pelvic viscera

NERVE
Anterior primary rami (perineal branches) of S3, 4

Question 16

OBTURATOR INTERNUS

Answer 16

ORIGIN
Inner surface of obturator membrane and rim of pubis and ischium bordering membrane

INSERTION
Middle part of medial aspect of greater trochanter of femur

ACTION
laterally rotates and stabilizes hip

NERVE
Nerve to obturator internus (L5, S1,2)

Question 17

PIRIFORMIS

Answer 17

ORIGIN
2, 3, 4 costotransverse bars of anterior sacrum, few fibers from superior border of greater sciatic notch

INSERTION
Anterior part of medial aspect of greater trochanter of femur

ACTION
laterally rotates and stabilizes hip

NERVE
Anterior primary rami of S1, 2

Question 18

SPHINCTER ANI

Answer 18

ORIGIN
Circular anatomical sphincter

INSERTION
Deep, superficial and subcutaneous portions

ACTION
Maintains continence of faeces

NERVE
Inferior rectal branch of pudendal nerve (S2, 3, 4)

Question 19

SPHINCTER URETHRAE

Answer 19

ORIGIN
Circular anatomical sphincter

INSERTION
Fuses with deep transverse perinei

ACTION
Maintains continence of urine

NERVE
Perineal branch of pudendal nerve (S2,3,4)

Question 20

SUPERFICIAL TRANSVERSE PERINEI

Answer 20

ORIGIN
Body of ischium

INSERTION
Perineal body

ACTION
Fixes perineal body

NERVE
Perineal branch of pudendal nerve (S2, 3, 4)