The Fetal Skull

Question 1

Which part of the fetal skull is called the VAULT?

Answer 1

Extends from the orbital ridges to the nape of the neck.
It is large and dome shaped.
It has the ability to compress during labour allowing the skull to slightly alter its shape

Question 2

Which bones does the Vault comprise of?

Answer 2

2 Frontal Bones
2 Parietal Bones
2 Temporal Bones
1 Occipital Bone

Question 3

Describe the FACE of the fetal skull

Answer 3

Composed of 14 small bones which are firmly united and non-compressible.
The face is small in the newborn extending from the orbital ridges and the root of the nose to the junction of the chin (mentum) and the neck.
The mandible is poorly developed

Question 4

Describe the BASE of the fetal skull

Answer 4

Located under the vault and behind the face.

Comprises of bones that are firmly united to protect the vital centres in the medulla.

Question 5

Name the DIVISIONS of the fetal skull

Answer 5

Vault
Face
Base

Question 6

Name the REGIONS of the fetal skull

Answer 6

Sinciput
Vertex
Occiput

Question 7

Describe the SINCIPUT

Answer 7

Extends from the anterior fontanelle and the coronal suture (division of bone down sides of skull from anterior fontanelle) to the orbital ridges (bridge of nose)

Question 8

Describe the VERTEX

Answer 8

Is the area/region bounded in front by the anterior fontanelle, behind by the posterior fontanelle and laterally by the parietal eminences

Question 9

Describe the OCCIPUT

Answer 9

This region lies between the foramen magnum (hole in base of skull where it attached to the spine) and the posterior fontanelle

Question 10

What is a SUTURE?

Answer 10

Cranial joints which are formed where two bones adjoin

Question 11

What is a FONTANELLE?

Answer 11

Where two or more sutures meet

Question 12

What is a SINUS?

Answer 12

A naturally occurring cavity in the body, in this instance in the cranial bones. Sinuses also enable blood to circulate throughout the skull and membranes of the brain

Question 13

Where is the FRONTAL SUTURE located?

Answer 13

From the middle of the front of the vault leading to the Anterior Fontanelle

Question 14

Where is the CORONAL SUTURE located?

Answer 14

From the Anterior Fontanelle leading down both sides of the skull

Question 15

Where is the ANTERIOR FONTANELLE located?

Answer 15

Largest gap between bones on the crown of the skull

Question 16

What is the PARIETAL EMINENCE and where is it located?

Answer 16

Located on Parietal Bones (sides of skull) and marks where ossification began

Question 17

Where is the SAGITTAL SUTURE located?

Answer 17

From the Anterior Fontanelle down the middle of the skull to the Posterior Fontanelle

Question 18

Where is the POSTERIOR FONTANELLE located?

Answer 18

At the back of the skull, above the Occipital Bone

Question 19

Where is the OCCIPITAL BONE located?

Answer 19

At the back of the skull

Question 20

Where is the LAMBDOIDAL SUTURE located?

Answer 20

From the Posterior Fontanelle and between the Parietal and Occipital bones

Question 21

Where and how long is the SOB diameter and what does it stand for?

Answer 21

From Anterior Fontanelle to Suboccipital Region
9.5 cm
Suboccipitobregmatic

Question 22

Where and how long is the SOF diameter and what does it stand for?

Answer 22

From Sinciput to Suboccipital Region
10cm
Suboccipitofrontal

Question 23

Where and how long is the OF diameter and what does it stand for?

Answer 23

From Glabella (bridge of nose) to Occipital Protuberence
11.5cm
Occipitofrontal

Question 24

Where and how long is the MV diameter and what does it stand for?

Answer 24

From middle of Saggital Suture to Mentum (point of chin)
13.5cm
Mentovertical

Question 25

Where and how long is the SMV diameter and what does it stand for?

Answer 25

From middle of Saggital Suture to back of the jaw
11.5cm
Submentovertical

Question 26

Where and how long is the SMB diameter and what does it stand for?

Answer 26

From Anterior Fontanelle to back of the jaw
9.5 cm
Submentobregmatic

Question 27

Identify and define the TWO transverse diameters of the fetal skull and their measurements

Answer 27

Biparietal - Widest part of skull when looking from above (across parietal bones) - 9.5cm

Bitemporal - Distance between temples - 8.2cm