The Cranial bones and the Pterion Flashcards
What are the 4 main bones of the skull and how are they positioned?
Frontal bone (at the front)
Parietal bone (from side of frontal round to the centre of the head at the back)
Temporal bone ('temples' area, on the side of the skull)
Occipital bone (back of the skull)Where are the maxilla and mandible bones?
Maxilla - top of the mouth (lower half of the cheek)
Mandible - lower jaw
Where are the sphenoid, zygomatic, nasal, and ethmoid bones?
Sphenoid - just lateral to and at the back of, the eye socket
Zygomatic - cheek bone, just inferior to the eye socket
Nasal bone - bridge of the nose
Ethmoid bone - back of the inside of the nose
Where is the palatine bone found?
Back of the top of the mouth (above the teeth)
Where are the conchae found and what different types are there?
Found inside the nose (behind the nasal bones)
- superior
- middle
- inferior
The superior and middle are one bone but in two parts, separated by the ethmoid bone. The inferior conchae is a separate bone to this.
Where is the lacrimal bone found?
Inside the nose, between the nasal bone and the conchae in depth
What is the Pterion and where is it located?
The pterion is the region where the frontal, parietal, temporal and sphenoid bones join together.
- It is located on the side of the skull, just behind the temple
Where is the vomer? (bone)
It lies in the mid-sagittal line forming the interior part of the nasal septum.
In totality, which bones and how many of each are present in a normal human cranium?
1 frontal, 2 parietal, 1 occipital, 2 temporal, 1 sphenoid, 1 ethmoid, 2 nasal, 2 maxilla (maxillary), 1 mandible, 2 nasal conchae, 2 lacrimal, 2 palatine, 1 vomer.
What is important about the Pterion?
It is a particularly weak part of the skull.
The middle meningeal artery lies below this bone so a fracture or damage to this area can result in an epidural haemorrhage.
