Abd/Pelvic Mm - Origin & Insertion

Question 1

Rectus abdominis

Answer 1

O - pubic crest, pubic tubercle

I - cartilage of ribs 5-7, xiphoid process

Question 2

external oblique

***two insertion points

Answer 2

O - lower 8 ribs (5th-12th)

membranous portion I - iliac crest
tendinous portion I - linea alba

Question 3

internal oblique

Answer 3

O - ant 2/3 of iliac crest, lat 2/3 of inguinal ligament, thoracolumbar fascia (posteriorly)

I - cartilage of last 3-4 ribs and linea alba

Question 4

transversus abdominis

***3 heads of origin, one point of insertion

Answer 4

pelvic head O - inner lip of iliac crest, lat 1/3 of inguinal lig

costal head O - inner surface of lower 6 costal cartilages, interdigitates with diaphragm

lumbar head O - lumbar vertebrae by thoracolumbar fascia

I - linea alba (contributes to rectus sheath)

Question 5

quadratus lumborum

Answer 5

O - lower border of 12th rib, TP of L1-L4

I - iliac crest, iliolumbar lig

Question 6

iliacus

Answer 6

O - upper 2/3 of iliac fossa, inner lip of iliac crest, ventral sacro-iliac and iliolumbar ligs, sup surf of lat sacrum

I - lesser trochanter w conjoined tendon of psoas major (iliopsoas)

Question 7

psoas major

Answer 7

O - vertebral bodies of T12-L5 and discs bw, TP of L1-L5

I - lesser trochanter w conjoined tendon of iliacus (iliopsoas)

Question 8

piriformis

Answer 8

O - ant surf of sacrum (exits pelvis via greater sciatic foramen)

I - greater troch

Question 9

obturator internus

Answer 9

O - medial side of os coxae around obturator foramen, obturator membrane (passes through lesser sciatic foramen)

I - greater troch

Question 10

ischiococcygeus

Answer 10

O - ischial spine

I - inferior sacrum, coccyx

Question 11

iliococcygeus

Answer 11

O - tendinous arch of obturator internus fascia

I - anococcygeal lig

Question 12

pubococcygeus

Answer 12

O - pubis

I - anococcygeal lig

Question 13

puborectalis

Answer 13

O - pubis, inf to pubococcygeus

I - blends with fibers of opposite side (forms sling around anal canal)

Question 14

superficial transverse perineus

Answer 14

O - ischial tuberosity

I - perineal body (central tendon) of perineum

Question 15

bulbospongiosus

Answer 15

O - perineal body (central tendon)

I - inf fascia of urogenital diaphragm

– males: corpus spongiosum of penis, deep fascia on dorsum of penis

– females: pubic arch, root/dorsum of clitoris

Question 16

ischiocavernosus

***insertion point different for male/female

Answer 16

O - ischial tuberosity, ischial/pubic rami

male I - corpus cavernosum of penis

female I - clitoris

Question 17

deep transverse perineus

Answer 17

O - ischial rami

I - perineal body (central tendon)

Question 18

external urethral sphincter

***insertion point different for male/female

Answer 18

O - ischial and pubic rami

male I - median raphe

female I - vaginal wall

Question 19

external anal sphincter (deep, superficial, subcutaneous parts)

Answer 19

O - anococcygeal raphe

I - central tendon

Question 20

internal intercostals

Answer 20

O - Lateral edge of costal groove of rib directly above

I - Superiorly on rib directly below

Question 21

external intercostals

Answer 21

O - Lower border of ribs

I - Upper border of rib below

Question 22

what mm contributes to the formation of the posterior rectus sheath?

Answer 22

transversus abdominis

Question 23

extends between ASIS & pubic tubercle

Answer 23

inguinal ligament

Question 24

what mm make up the pelvic floor?

Answer 24

1. ischio-coccygeus
2. levator ani

Question 25

what 3 mm make the levator ani muscle?

Answer 25

1. ilio-coccygeus
2. pubo-coccygeus
3. puborectalis