The Fetal Skull Flashcards
Which part of the fetal skull is called the VAULT?
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
Which bones does the Vault comprise of?
2 Frontal Bones
2 Parietal Bones
2 Temporal Bones
1 Occipital Bone
Describe the FACE of the fetal skull
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
Describe the BASE of the fetal skull
Located under the vault and behind the face.
Comprises of bones that are firmly united to protect the vital centres in the medulla.
Name the DIVISIONS of the fetal skull
Vault
Face
Base
Name the REGIONS of the fetal skull
Sinciput
Vertex
Occiput
Describe the SINCIPUT
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)
Describe the VERTEX
Is the area/region bounded in front by the anterior fontanelle, behind by the posterior fontanelle and laterally by the parietal eminences
Describe the OCCIPUT
This region lies between the foramen magnum (hole in base of skull where it attached to the spine) and the posterior fontanelle
What is a SUTURE?
Cranial joints which are formed where two bones adjoin
What is a FONTANELLE?
Where two or more sutures meet
What is a SINUS?
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
Where is the FRONTAL SUTURE located?
From the middle of the front of the vault leading to the Anterior Fontanelle
Where is the CORONAL SUTURE located?
From the Anterior Fontanelle leading down both sides of the skull
Where is the ANTERIOR FONTANELLE located?
Largest gap between bones on the crown of the skull
What is the PARIETAL EMINENCE and where is it located?
Located on Parietal Bones (sides of skull) and marks where ossification began
Where is the SAGITTAL SUTURE located?
From the Anterior Fontanelle down the middle of the skull to the Posterior Fontanelle
Where is the POSTERIOR FONTANELLE located?
At the back of the skull, above the Occipital Bone
Where is the OCCIPITAL BONE located?
At the back of the skull
Where is the LAMBDOIDAL SUTURE located?
From the Posterior Fontanelle and between the Parietal and Occipital bones
Where and how long is the SOB diameter and what does it stand for?
From Anterior Fontanelle to Suboccipital Region
9.5 cm
Suboccipitobregmatic
Where and how long is the SOF diameter and what does it stand for?
From Sinciput to Suboccipital Region
10cm
Suboccipitofrontal
Where and how long is the OF diameter and what does it stand for?
From Glabella (bridge of nose) to Occipital Protuberence
11.5cm
Occipitofrontal
Where and how long is the MV diameter and what does it stand for?
From middle of Saggital Suture to Mentum (point of chin)
13.5cm
Mentovertical
Where and how long is the SMV diameter and what does it stand for?
From middle of Saggital Suture to back of the jaw
11.5cm
Submentovertical
Where and how long is the SMB diameter and what does it stand for?
From Anterior Fontanelle to back of the jaw
9.5 cm
Submentobregmatic
Identify and define the TWO transverse diameters of the fetal skull and their measurements
Biparietal - Widest part of skull when looking from above (across parietal bones) - 9.5cm
Bitemporal - Distance between temples - 8.2cm
