Week 1 - The Bony Pelvis

Question 1

What does the bony pelvis consist of?

Answer 1

2 innominate bones, sacrum and coccyx

Question 2

The pelvic girdle (bony ring) does not include which part of the bony pelvis?

Answer 2

Coccyx

Question 3

Each innominate bone is a fusion between what other bones?

Answer 3

Ilium, ischium and pubis

Question 4

The two sides of the bony pelvis connect where:

a) anteriorly?
b) posteriorly?

Answer 4

a) Pubic symphysis

b) Sacro-iliac joints

Question 5

Which bone is this describing - ‘the flattened, superior, fan-shaped part of the hip bone’?

Answer 5

Ilium

Question 6

Where does the iliac crest pass from?

Answer 6

ASIS to PSIS

Question 7

The iliac fossa is an attachment for which muscle?

Answer 7

Iliacus

Question 8

What sits in the left iliac fossa?

Answer 8

Sigmoid colon

Question 9

What are the two parts of the ischium?

Answer 9

Body and ramus

Question 10

The body of the ischium forms the posterior part of what structure?

Answer 10

Acetabulum

Question 11

The ramus of the ischium forms the posterior part of what structure?

Answer 11

The inferior obturator foramen

Question 12

The ischiopubic ramus is located where in relation to the ischial ramus?

Answer 12

Medial

Question 13

What part of the ischium do we sit on?

Answer 13

The ischial tuberosity

Question 14

Which group of muscles originate from the ischial tuberosity?

Answer 14

Hamstrings

Question 15

The pubis is an angulated bone, which is formed of the superior pubic ramus that forms the anterior part of which structure?

Answer 15

Acetabulum

Question 16

The inferior pubic ramus forms the inferior border of what structure?

Answer 16

Obturator foramen

Question 17

The pubic tubercle is the attachment for which ligament?

Answer 17

Inguinal ligament

Question 18

The two pubis bones are connected where?

Answer 18

Pubic symphysis

Question 19

Which bone of the pelvis is most different between males and females?

Answer 19

Pubis

Question 20

What is the different in the pubic arch in males and females?

Answer 20

This has a wider angle and flares out more in females than males

Question 21

What are the 3 joints of the pelvis?

Answer 21

Hip joint, sacroiliac and pubic symphysis

Question 22

What is the stability and movement of the sacroiliac joints?

Answer 22

Small amount of movement but overall are very stable

Question 23

What type of joint is the pubic symphysis?

Answer 23

Cartilagenous

Question 24

Why does the pubic symphysis need to have more mobility than the sacroiliac joints?

Answer 24

To allow it to expand during pregnancy

Question 25

What type of joint is the hip?

Answer 25

Synovial ball and socket

Question 26

Where does the inguinal ligament attach between?

Answer 26

ASIS and pubic tubercle

Question 27

Which structures of the pelvis are palpable on vaginal examination, at approx 4 and 8 o clock positions?

Answer 27

Ischial spines

Question 28

Why are the ischial spines clinically relevant?

Answer 28

For administering a pudendal nerve block, and assessing how far through the pelvis a foetal head is

Question 29

The iliac crests are at what spinal level?

Answer 29

L4

Question 30

What is the role of the sacrospinous and sacrotuberous ligaments?

Answer 30

To ensure that the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred through the vertical column

Question 31

What happens to the ligaments of the pelvis in pregnancy?

Answer 31

Hormones are released which cause them to relax to allow for the foetus to grow

Question 32

The presence of the sacrospinous and sacrotuberous ligaments forms what other structures?

Answer 32

Greater and lesser sciatic foraminae

Question 33

Structures which pass through the sciatic foraminae are heading towards where?

Answer 33

Perineum or lower limb

Question 34

What structures form the pelvic inlet?

Answer 34

Sacral promontory, ilium, superior pubic ramus and pubic symphysis

Question 35

What is the sacral promontory?

Answer 35

S1 vertebral body

Question 36

What structures form the pelvic outlet?

Answer 36

Pubic symphysis, ischiopubic ramus, ischial tuberosities, sacrotuberous ligaments and coccyx

Question 37

Above the pelvic inlet there is an area known as the 'false pelvis' - this is part of what cavity?

Answer 37

Abdominal cavity

Question 38

What is the main difference between the structures forming the pelvic inlet and outlet?

Answer 38

Inlet is completely bony while the outlet is formed of bones and ligaments

Question 39

Where does the pelvic cavity lie within?

Answer 39

The bony pelvis

Question 40

The pelvic cavity lies between which two structures?

Answer 40

Pelvic inlet and pelvic floor

Question 41

What muscle forms the inferior parts of the pelvic cavity, and is also known as the pelvic floor?

Answer 41

Levator ani

Question 42

What is found below the pelvic cavity?

Answer 42

Perineum

Question 43

In terms of mechanics, how do fractures tend to occur in the pelvis?

Answer 43

They are usually multiple, or combined with a joint dislocation

Question 44

Trauma to the bony pelvis can result in what?

Answer 44

Life threatening haemorrhage +/- damage to the pelvic organs

Question 45

Disruption to any vasculature in the pelvis will cause what?

Answer 45

Internal bleeding

Question 46

What is the difference in the diameters of the pelvis in males vs. females?

Answer 46

All diameters of the pelvis are larger in the female

Question 47

What is the difference in the pelvic cavities between males and females?

Answer 47

Shallower in females (i.e. less distance between inlet and outlet)

Question 48

What is 'moulding'?

Answer 48

The bones of the baby's skull moving over each other to allow the foetal head to pass through the pelvis in labour

Question 49

The presence of what in a baby's skull allow moulding?

Answer 49

Fontanelles and sutures

Question 50

What is the following a sign of: a) bulging fontanelles? b) depressed fontanelles?

Answer 50

a) Raised ICP | b) Malnutrition

Question 51

How long does it take for each type of fontanelle to close?

Answer 51

Posterior takes around 3-6 months while anterior takes 9-18 months

Question 52

What is the vertex?

Answer 52

An area of the foetal skull which is outlined by the anterior and posterior fontanelles and the parietal eminences

Question 53

Which diameter of the foetal skull is the largest?

Answer 53

Occipitofrontal

Question 54

Which diameter of the pelvis is largest at the pelvic inlet? As a result of this, how should the foetus ideally enter the pelvic cavity?

Answer 54

Transverse - ideally facing either to the right or left (transverse) direction

Question 55

While descending through the pelvic cavity, what should happen to the foetal head?

Answer 55

Rotate, and be in a flexed position

Question 56

Which diameter of the pelvis is largest at the pelvic outlet? As a result of this, how should the foetus ideally leave the pelvic cavity?

Answer 56

AP diameter - ideally in an occipitoanterior (OA) position

Question 57

During the delivery, should the foetal head be extended or flexed?

Answer 57

Extended

Question 58

What movement of the baby needs to occur once the head has been delivered?

Answer 58

Further rotation to allow one shoulder out and then another

Question 59

Where does the sacrospinous ligament attach between?

Answer 59

Ischial spines and sacrum

Question 60

Where does the sacrotuberous ligament attach between?

Answer 60

Ischial tuberosities and sacrum

Question 61

What is the difference in the shape of the pelvic outlet in males and females?

Answer 61

Males = more heart shaped, females = more oval shaped

Question 62

What is the difference in the sacral promontory between males and females?

Answer 62

More anterior in males