Occipital Bone Flashcards
Where is the foramen magnum
The big hole!
Which is the squamous part of the occipital bone
The large flatter piece of bone
Where is the basilar part of the occipital bone
This is the most inferior point, it is thick and square in shape
Where are the lateral parts of the occipital bone
These are the parts which lie either side to the foramen magnum
Where is the lambdoid margin
Across the top of the squamous part
Where is the mastoid margin
These are on each side of the occipital bone above the jugular notch
Where is the Jugular notch
These are under the mastoid margins, the medial and lateral points
Where is the external occipital protuberance
On the exocranial view where the occipital and nuchal planes meet
Which nuchal lines can we see and where are they
All three and on the exocranial side
Where is the external occipital crest
This is the line up the middle of the bone from the foramen magnum on the exocranial view
Where are the occipital condyles
on the exocranial view these are the oval structures either side of the foramen magnum
Where is the condylar fossa
These are on the exocranial side above the condyles - sometimes canals
Where are the hypoglossal canals
These are on the exocranial side and are found under the condyles
Where is the jugular process
These are at the end of the mastoid margins and are corners of bone
Where is the jugular tubercle
On both sides near the jugular process and is a small bump
Where is the cerebellar fossa
These are on the endocranial surface
Where is the cerebral fossae
These are triangular depressions below the lambdoid margin on the endocranial surface
Where is the internal occipital protuberance
Lies at the centre of the cruciform eminence
Where is the Cruciform eminence
This divides the endocranial surface into four - the cross shape
Where is the occipital sulcus or groove for the sagittal fossa
Runs down the centre of the bone from the lambdoid margin to the cruciform eminence
Where is the internal occipital crest
Above the foramen magnum on the endocranial side runs up to the cruciform eminence
Where is the transverse sulci or groove for the transverse sinus
This is the groove that runs horizontally across the bone on the endocranial side
Where is the groove for the medulla oblongata
This is found on the endocranial side and is a hollowing on the basilar part
Where is the pharyngeal tubercle
This is on the exocranial side of the basilar part and is a small bump
Where is the groove for the sigmoid sinus
These are found just above the lateral parts if there is one on the endocranial side
Where is the BOBBS located
This is on the basilar part, if it is unfused then the individual is young
How would you side an occipital bone
When in one piece this isn’t needed. For isolated condyles the foramen magnum edges are medial and posterior
