Pelvic Walls and Floor

Question 1

what bones form the pelvis?

Answer 1

right and left innominate bones with the sacrum in the middle

Question 2

where is the greater sciatic notch?

Answer 2

between the ala of the innominate bones and ischial spine

Question 3

what does the greater sciatic notch transmit?

Answer 3

piriformis
superior gluteal vessels and nerves
inferior gluteal vessels and nerves
sciatic nerve
posterior femoral cutaneous nerve
internal pudendal artery and vein
nerve to obturator internus
nerve to quadratus femoris

Question 4

what does the external surface of the ischial spine give attachment to?

Answer 4

gemellus superior

Question 5

what does the internal surface of the ischial spine give attachment to?

Answer 5

coccygeus
levator ani
pelvic fascia

Question 6

what does the pointed extremity of the ischial spine give attachment to?

Answer 6

sacrospinous ligament

Question 7

what attaches to the ischial spine?

Answer 7

gemellus superior
coccygeus
levator ani
pelvic fascia
sacrospinous ligament

Question 8

where is the lesser sciatic notch?

Answer 8

between the ischial spine and ischial tuberoisty of the innominate bones

Question 9

what ligaments convert the lesser sciatic notch into the lesser sciatic foramen?

Answer 9

sacrotuberous and sacrospinous ligaments

Question 10

what does the lesser sciatic notch transmit?

Answer 10

tendon of obturator internus
nerve to obturator internus
pudendal nerve
internal pudendal vessels

Question 11

what does the lower portion of the ischial tuberosity give attachment to?

Answer 11

outer: adductor magnus
inner: sacrotuberous ligament

Question 12

what does the upper portion of the ischial tuberosity give attachment to?

Answer 12

upper + outer: semimembranosus

lower + inner: long head of biceps femoris and semitendinosus

Question 13

what does the obturator foramen transmit?

Answer 13

obturator artery, vein and nerve (out of the pelvis)

Question 14

where does the sacrospinous ligament run from and to?

Answer 14

ischial spine (pointed extremity) to sacrum

Question 15

where does the sacrotuberous ligament run from and to?

Answer 15

sacrum to upper and inner portion of the ischial tuberosity

Question 16

what type of joint is the pubic symphysis?

Answer 16

secondary cartilaginous

Question 17

what articulates at the pubic symphysis?

Answer 17

left and right innominate bones

Question 18

what type of joint is the lumbosacral joint?

Answer 18

secondary cartilaginous

Question 19

what articulates at the lumbosacral joint?

Answer 19

L5 and the sacrum

Question 20

what articulates at the sacroiliac joint?

Answer 20

sacrum and iliac crest

Question 21

what ligaments hold together the sacroiliac joint (and what type of joints do they create)?

Answer 21

anterior sacroiliac ligament: synovial

posterior sacroiliac ligament: fibrous

Question 22

what ligaments convert the greater sciatic notch into the greater sciatic foramen?

Answer 22

sacrotuberous and sacrospinous ligaments

Question 23

what forms the anterior boundary of the pelvis?

Answer 23

pubic bodies
pubic rami
pubic symphysis

Question 24

what forms the posterior boundary of the pelvis?

Answer 24

sacrum
coccyx
piriformis

Question 25

what forms the inferior boundary of the pelvis?

Answer 25

muscular sheet forming the pelvic boundary

Question 26

what forms the superior boundary of the pelvis?

Answer 26

there is no boundary - it's an open space!

Question 27

what is the difference in the shape of the innominate bones in males vs females?

Answer 27

males: acute angle at pubic symphysis, higher ala and smaller pelvic inlet females: obtuse angle at pubic symphysis, flatter ala and wider pelvic inlet

Question 28

what is iliacus found?

Answer 28

iliac fossa, then joins with the psoas and iliopsoas --> lesser trochanter of femur

Question 29

what is the function of iliacus?

Answer 29

hip flexion

Question 30

what is the innervation of the iliacus?

Answer 30

femoral nerve (L2-4)

Question 31

where is psoas?

Answer 31

bodies and IV discs of L1-5 (deep) and of T12-L4 (superficial) --> lesser trochanter of the femur, after joining with the iliacus and iliopsoas

Question 32

what are the functions of psoas?

Answer 32

one: bend trunk laterally both: raise trunk from supine position

Question 33

what is the innervation of psoas?

Answer 33

anterior rami L2-4, from lumbar plexus

Question 34

where is obturator externus?

Answer 34

outer surface of obturator membrane --> trochanteric fossa of femur

Question 35

what is the function of obturator externus?

Answer 35

lateral rotation and stabilisation of hip

Question 36

what is the innervation of obturator externus?

Answer 36

posterior branch of obturator (L3+4)

Question 37

where is obturator internus?

Answer 37

inner surface of obturator membrane --> trochanteric fossa of femur, passes through lesser sciatic foramen

Question 38

what is the function of obturator internus?

Answer 38

lateral rotation of hip

Question 39

what is the innervation of obturator internus?

Answer 39

nerve to obturator internus, direct from sacral plexus (L5+S1)

Question 40

where is piriformis?

Answer 40

pelvic surface of sacrum --> greater trochanter of femur

Question 41

where is the function of piriformis?

Answer 41

lateral rotation of hip joint

Question 42

what is the innervation of piriformis?

Answer 42

nerve to piriformis, direct branch from sacral plexus (S1+2)

Question 43

what muscle forms the roof of the anal triangle?

Answer 43

levator ani

Question 44

what muscles form the pelvic diaphragm?

Answer 44

levator ani | coccygeus

Question 45

what is the function of the pelvic diaphragm?

Answer 45

muscular floor to prevent prolapse

Question 46

where is coccygeus?

Answer 46

ischial spine and sacrospinous ligament --> coccyx and inferior sacrum

Question 47

what is the function of coccygeus?

Answer 47

flexion of coccyx | support pelvic viscera

Question 48

what is the innervation of coccygeus?

Answer 48

direct branches from the sacral plexus (S4+5)

Question 49

what are the two parts of levator ani?

Answer 49

pubococcygeus and iliococcygeus

Question 50

what are the roles and movements of levator ani?

Answer 50

supports pelvic viscera contract during forced expiration, coughing etc. relaxes to allow urination and defecation

Question 51

which part of levator ani is formed of the most medial fibres?

Answer 51

pubococcygeus

Question 52

which part of leavtor ani is formed of the more lateral fibres?

Answer 52

iliococcygeus

Question 53

what is the role of pubococcygeus?

Answer 53

support the vagina/prostate gland and rectum

Question 54

where does the pubococcygeus attach?

Answer 54

vagina/prostate gland and rectum

Question 55

what are the three divisions of pubococcygeus?

Answer 55

puborectalis levator prostate (puboprostaticus) pubovaginalis

Question 56

where is the puborectalis found?

Answer 56

around the rectum

Question 57

where is the levator prostate (puboprostaticus) found?

Answer 57

around the prostate (male only)

Question 58

where is the pubovaginalis found?

Answer 58

around the vagina (female only)

Question 59

where is the iliococcygeus found?

Answer 59

anterior to coccygeus, posterior to pubococcygeus

Question 60

what innervates pubococcygeus?

Answer 60

``` pudendal nerve (S2-4) nerve to levator ani (S4) ```

Question 61

what component of pubococcygeus is found in males, and where do its fibres run?

Answer 61

most medial pass around the prostate and insert into perineal body (levator prostate)

Question 62

what component of pubococcygeus is found in females, and where do its fibres run?

Answer 62

most medial fibres pass around the vaina and insert into perineal body (pubovaginalis)

Question 63

what component of pubococcygeus is found in both sexes, and where are it's fibres found?

Answer 63

fibres mix with those from the external anal sphincter, modified as a sling around the rectum (puborectalis)

Question 64

what is the function of puborectalis?

Answer 64

maintain faecal continence, especially important after the rectum has filled (so internal anal sphincter open)

Question 65

what is the anococcygeal raphe and where is it found?

Answer 65

connective tissue in the floor of the pelvis, between the coccyx and the posterior margin of the anus

Question 66

fibres of what form the anococcygeal raphe?

Answer 66

levator ani as they unite with the muscle on the opposite size

Question 67

where does the iliococcygeus attach?

Answer 67

fascia of obturator internus and anococcygeal raphe

Question 68

which of the iliococcygeus and pubococcygeus is more fibrous?

Answer 68

iliococcygeus

Question 69

what name is given to the area of the fascia of obturator internus that levator ani attaches to?

Answer 69

tendinous arch of levator ani

Question 70

what is the perineal body composed of?

Answer 70

fibrous connective tissue

Question 71

what attaches to the perineal body?

Answer 71

levator prostate pubovaginalis external anal sphincter perineal muscles

Question 72

what is the equivalent of the perineal body between the anus and coccyx?

Answer 72

anococcygeal raphe

Question 73

where is the perineal body found?

Answer 73

females: between the anus and vulva males: between anus and scrotum

Question 74

what does the parietal pelvic fascia cover?

Answer 74

the internal pelvic wall

Question 75

what does the thickened portion of parietal pelvic fascia over the obturator internus form?

Answer 75

tendinous arch of the pelvis (and levator ani)

Question 76

what does the anterior portion of parietal pelvic fascia give rise to in males?

Answer 76

puboprostatic ligament

Question 77

what does the anterior portion of parietal pelvic fascia give rise to in females?

Answer 77

pubovesical ligament

Question 78

what does the visceral pelvic fascia cover?

Answer 78

pelvic organs

Question 79

what does the lateral extension of visceral pelvic fascia from the vagina to the tendinous arch give rise to?

Answer 79

the paracolpium (the vascular and connective tissue alongside the vagina)

Question 80

at what point does the parietal and visceral pelvic fascia blend?

Answer 80

when the organs pierce the pelvic floor

Question 81

what is the role of the endopelvic fascia?

Answer 81

packing material around the organs

Question 82

what are the two basic types of endopelvic fascia?

Answer 82

loose and condensed

Question 83

where is the loose endopelvic fascia found?

Answer 83

in the spaces in the pelvis | e.g. retropubic (pre-vesical) space

Question 84

what is the condensed fascia formed of and where is it found?

Answer 84

thickenings of the endopelvic fascia, the primary condensation is the hypogastric sheaths running along the posterolateral walls of the pelvis