What is the upper part of the cranium called
What are the three layers of all of the bones of the skull?
External & internal layers of compact bone, with a middle layer of spongy bone (the diploe)
What are the skull sutures?
Immobile joint between the seperate bones
Name the four "main" sutures
What bones form the coronal suture?
Frontal bone and the 2 parietal bones
What bones form the saggital suture?
The two parietal bones
What bones form the lambdoid suture?
The two parietal bones and the occipital bone
Which two sutures are in the coronal plane?
Coronal & lamboid
What bones form the pterion?
What is the significance of the pterion?
The bones are thin at this point, making it a site of weakness
The middle meningeal artery runs directly deep to the pterion
What are the 2 parts of the frontal bone?
The vertical part (forehead)
The horizontal part (forming the anterior cranial fossa and roof of the orbit)
What is the line of demarcation between the 2 parts of the frontal bone?
The supraorbital margins
Describe the parietal bone
Flat, rectangular bone moulded to brain contour
Describe the features of the occipital bone
Flat, moulded to posterior aspect of brain
Prominent external occipital protuberance
What are the 4 processes of the temporal bone?
What is the flat "body" of the temporal bone called?
The squamous part
Describe the zygomatic process
A thin, forward projection that articulates with the zygomatic bone
Describe the mastoid process
A thick, chunky, downwards projection
Describe the styloid process
Deep, sharp, downwards projection
What structures attach to the styloid process of the temporal bone?
Ones for the oral cavity & pharynx
Describe the petrous process of the temporal bone
A chunky, pyramid shaped, inwards projection
What are the main features of the sphenoid bone
A body with two wings The body (including sella turcica) has a depression (the hypophysial fossa) for the pituitary gland The superior orbital fissure divides the wings into the lesser (anterosuperior) and greater (posterior) wings
What features of the ethmoid bone are visible from inside the cranium?
The cribiform plate, with lots of tiny holes The christa galli