Anatomy of the Pelvis

Question 1

List the functions of the bony pelvis

Answer 1

Support of the upper body when sitting and standing

Transferrence of weight from the vertebral column to the femurs to allow standing and walking- one column -> two columns

Attachment for muscles of locomotion and abdominal wall

Attachment for external genitalia

Protection of pelvic organs, their blood and nerve supplies, their venous and lymphatic drainage

Passage for childbirth

Question 2

What does the bony pelvis consist of?

Answer 2

2 hip bones
Sacrum
Coccyx

Question 3

What is each hip bone made up of?

Answer 3

Fusion between ilium, ischium, pubis

Question 4

What is not part of the pelvic girdle?

Answer 4

Coccyx

Question 5

What generally covers the iliac fossa?

Answer 5

The iliacus

Question 6

To what do the hamstring s attach?

Answer 6

Ischial tuberosity

Question 7

Described the pelvic inlet

Answer 7

• Sacral promontory- prominent
• Ilium
• Superior pubic ramus
• Pubic symphysis

Question 8

Describe the pelvic outlet

Answer 8

• Pubic symphysis
• Ischiopubic ramus
• Ischian tuberosities
• Sacrotuberous ligaments
• Coccyx

Question 9

what is commonly called the pelvic rim?

Answer 9

Bony edge of pelvic inlet

Question 10

What is continuous with the abdominal cavity?

Answer 10

Pelvic cavity

Question 11

What is within the pelvic cavity?

Answer 11

Pelvic organs and supporting tissues

Question 12

What are the palpable surface landmarks?

Answer 12

Iliac crest
Ischial tuberosity
ASIS
PSIS

Question 13

What kind of joint is the sacroiliac?

Answer 13

generally referred to as a synovial joint- actually the posterior part is a syndesmoses (more fibrous ligaments)

Question 14

What are the key ligaments of the pelvis?

Answer 14

Sacrospinous ligament

Sacrotuberous ligament

Question 15

What is the role of the Sacrospinous and

Sacrotuberous ligament

Answer 15

Ensure the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebra column

Question 16

What covers the obturator foramen?

Answer 16

Obturator membrane, apart from the obturator canal

Question 17

What passes through the obturator canal?

Answer 17

Obturator nerves and vessels

Question 18

Why does the pelvis tend to fracture in more than one place?

Answer 18

It is a ring of bones- think pretzel

Question 19

What is often fatal about pelvic trauma?

Answer 19

Haemorrhage

Question 20

What is different about the male and female pelvises?

Answer 20

• AP and transverse diameters of the female pelvis are larger than in the male- this is true at both the inlet and the outlet.
• The subpubic arch and angle is much bigger in the female than in the male. If you put your thumb and index out- this is a female. 1st and 2nd finger is a male.
• Pelvic cavity is more shallow in the female.

Question 21

What is moulding?

Answer 21

Movement of one bone over another to allow the foetal head to pass through the pelvis during labour

Question 22

What are the clinically important fontanelles?

Answer 22

Anterior and posterior

Question 23

When should the anterior fontanelle close?

Answer 23

between 18-24 months

Question 24

What is the vertex?

Answer 24

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

Question 25

Why is the vertex important?

Answer 25

allows the skull to be palpated in labour

Question 26

In which way should the foetus enter the pelvic cavity?

Answer 26

Facing either right or left

Question 27

What is the station?

Answer 27

The distance of the foetal head from the ischial spines. A negative number means the head is superior to the spines, a positive number means the head is inferior to the spines.

Question 28

What way should the foetus pass through the pelvic cavity?

Answer 28

Rotate into a flexed position, chin to chest

Question 29

Which way should the baby leave the pelvis cavity?

Answer 29

Occipitoanterior position

Question 30

How should the foetal head be during delivery?

Answer 30

Extension

Question 31

What happens once the babies head is delivered?

Answer 31

Rotation so that the shoulders and the rest of the baby can be delivered.