The maternal pelvis, the fetal skull, mechanisms of normal labour and malpositions Flashcards Preview

Midwifery > The maternal pelvis, the fetal skull, mechanisms of normal labour and malpositions > Flashcards

Flashcards in The maternal pelvis, the fetal skull, mechanisms of normal labour and malpositions Deck (40)
Loading flashcards...
1

What part of the fetal skull is the sinciput?

- extends from the orbital ridges (bridge of the nose) to the anterior fontanelle and the coronal suture
- the sinciput is also called the brow.

2

What part of the fetal skull is the vertex?

Extends from the anterior fontanelle and the coronal suture to the posterior fontanelle and the lambdoidal suture

3

What part of the fetal skull is the occiput?

Extends from the posterior fontanell and the lambdoidal suture to the base of the skull

4

What are the bones of the fetal skull?

2 frontal bones
2 parietal bones
2 temporal bones
1 occipital bone

5

What is the suture between the two frontal bones?

the frontal suture

6

What is the suture between the frontal bones and the parietal bones?

the coronal suture

7

What is the suture that runs between the anterior fontanelle and the posterior fontanelle?

the sagittal suture

8

What is the suture that runs between the parietal bones and the occiput?

the lambdoidal suture

9

What is the shape, alternative name and position of the anterior fontanelle?

- diamond shaped
- also called bregma
- at the junction of the frontal, coronal and sagittal sutures

10

What is the shape, alternative name and position of the posterior fontanelle?

- triangular
- also called lambda
- bound by the sagittal and lambdoidal sutures

11

What are the 3 sections of the true pelvis?

- brim
- cavity
- outlet

12

What are the landmarks of the pelvic brim from back to front? Think about how these landmarks relate to position

- sacral promontory (Direct OP)
- sacroiliac joint (LOP/ROP)
- iliopectineal line (LOT/ROT)
- iliopectineal eminence (LOA/ROA)
- upper border of the symphysis pubis (Direct OA)

13

What are the 4 types of pelvis?

- Gynecoid
oval shaped, parallel sides, dull ischial spines and wide pubic arch (3 fingers)
- Android
heart-shaped, prominent ischial spines and narrow pelvic arch
- Anthropoid
longer front-to-back compared to gynecoid
- Platypelloid
longer side-to-side compared to gynecoid

14

What is the shape of the pelvic brim, and what are its anteroposterior, oblique and transverse diameters?

Oval or heart-shaped
AP 11cm
O 12cm
T 13cm
wider in the transverse diameter

15

What is the shape of the pelvic cavity, and what are its anteroposterior, oblique and transverse diameters?

Circular
AP 12cm
O 12cm
T 12cm
same width in AP and T diameters, allows space for rotation

16

What is the shape of the pelvic outlet, and what are its anteroposterior, oblique and transverse diameters?

Diamond
AP 13cm
O 12cm
T 11cm
wider in the AP diameter

17

What is the anatomical name for the top of your hip bones?

Iliac crests

18

What is the anatomical name for your sit bones?

Ischial tuberosities

19

What are the bones of the pelvis?

- 2 innominate bones each with an ilium, ischium and a pubic bone
- sacrum
- coccyx

20

What is the meeting point of your pubic bones called?

the pubic symphysis

21

What is the name for the underside of the pubic symphysis?

the pubic arch

22

What are the 4 pelvic joints?

- the pubic symphysis
between two pubic bones
- two sacroiliac joints
between sacrum and ilium
- the sacrococcygeal joint
between sacrum and coccyx

23

What is the curve of carus?

- the imaginary line which passes through the centre of the theoretical plane at the pelvic brim, cavity and outlet
- follows the curve of the sacrum
- the anterior wall of the pelvis (the pubic symphysis) is shorter than the posterior wall (the sacrum), which creates a curved canal

24

what are the landmarks of the pelvic outlet?

- sacrococcygeal joint
- ischial spines
- symphysis pubis

25

What is moulding (of the fetal skull)?

the change in the shape of the fetal head as it passes through the birth canal, possible due to slight bending and overlapping of the bones of the fetal skull

26

What is attitude of the fetal skull?

the degree of flexion or extension of the of the fetal head relative to the neck

27

What part of the fetal skull is the face?

extends from the orbital ridges to the junction of the chin and neck. the chin is called the mentum

28

What are the names and measurements of the two transverse diameters of the fetal skull?

The bitemporal diameter is 8.2cm and the biparietal diameter is 9.5cm

29

What are the presenting diameters in a well flexed vertex presentation?

the suboccipitobegmatic (SOB) diameter (9.5cm) and the biparietal diameter (9.5cm). These diameters form a circle and are most effective at dilating the cervix.

30

What are the presenting diameters in a deflexed vertex presentation?

the occipitofrontal (OF) diameter (11.5cm) and the biparietal diameter (9.5cm). These diameters mean the cervix tends to dilate more readily in the transverse than in the AP diameter.