Anatomy of the skull (the neurocranium) Flashcards
What is the skull spilt into?
The viscerocranium and the neurocranium
What bones make up the neurocranium?
8 bones:
- Frontal
- Parietal x2
- Temporal x2
- Occipital
- Sphenoid
- Erythmoid
What sutures does the frontal bone form? With which bones?
Coronal suture (Formed with the parietal bones)
Frontal (Metopic) suture (formed by either side of the frontal bone befrore fusion at 1-3 years old)
What is the Bregma?
The point at which the coronal and the saggital sutures meet (intersect each other)
What is the supraorbital foramen?
The foramen above the orbits
Lateral to the frontal notch
What is the frontal notch?
Notch medial to the supraorbital foramen
What is a tuberocity?
A rounded prominence on a bone for muscle/ligament attachment
What passes through the supraorbital foramen?
SupraORBITAL artery
Lateral branch of the supraOBITAL nerve
What passes through the frontal foramen?
SupraTROCHLEAR artery
Medial branch of the supraORBITAL nerve
What passes through the frontal foramen?
SupraTROCHLEAR artery
Medial branch of the supraORBITAL nerve
What is the function of the sphenoid bone?
- Attachment of muscles
- Give ridigity to the skull (makes up the base of the skull)
- Contributes to the middle cranial fossa
What are the parts of the sphenoid bone?
- Body
- Lesser wing
- Greater wing
- Pterygoid process
What does the body of the sphenoid contribute to?
The nasal cavity
Medial wall of the optic canal
What does the body of the sphenoid contribute to?
The nasal cavity
Medial wall of the optic canal
What sinuses do the sphenoid bone house and where?
The sphenoid sinuses (behind the nasal cavity and divided by the septum)
What does the lesser wing of the sphenoid contribute to?
The optic canal
Orbit
What does the optic canal contain?
The optic nerve and the infalmic? artery
What does the greater of the sphenoid contribute to?
Orbit
What are the pterygoid processes of the sphenoid?
Extensions of the basal surface of the body
What is the sphenooccipital suture?
What happens to it when age?
The suture between the sphenoid bone and the occipital bone
Fuses at the age of 25
What are the foramens of the greater wing of the sphenoid bone?
1) Foramen rotundum
2) Foramen ovale
3) Foramen spinosum
4) Foramen lacerum (medially)
What passes through the foramen roundum?
The MAXILLARY nerve
What passes through the foramen ovale?
The MANDUBULAR nerve
Accessory meningeal arteries
What passes through the foramen spinosum?
The SPINOUS nerve
The middle meningeal vessels
What passes through the foramne lacerum?
The artery and nerve of the pterygoid canal
Some venous drainage
What are the 3 main branches from the trigeminal nerve?
1) Optothalamic
2) Maxillary
3) Mandibular
What are the holes that can be seen in the occular orbits from the front of the skull?
1) Superior orbital fissure
2) Inferior orbital fissure
3) Optic canal
What is the superior orbital fissue?
Fissure that lies between the lesser and greater wings of the sphenoid bone
What passes through the superior orbital fissue?
Many blood vessels and nerves:
- Occulormotor nerve
- Trochlear nerve
- Abducens nerve
- OPHTHALAMIC nerve branches
- Opthalamic vein
Where is the optic canal?
In the lesser wing of the sphenoid bone
What passes through the optic canal?
The optic nerve
The ophthalmic artery
What is the sella turcica?
An indentation in the roof of the body of the sphenoid bone that houses the pituitary gland
What is the carotid sulcus?
Groove in the sphenoid bone that houses the carotid artery
What is the carotid canal?
Where can it be seen?
Passageway into the TEMPORAL bone
Can be seen:
1) From the underneath of the skull - in the temporal bone
2) From the internal skull - where the foramen lacerum is
What is the chiamsmatic groove?
Connects the 2 optic canals
Transmits the optic nerves
Which foramen of the greater wing of the sphenoid bone cannot be seen from the underside of the skull?
The foramen rotundum
