Lecture 4.1 - The Skull and Overview of Cranial Nerves Flashcards
What is the neurocranium?
- houses brain
- calvaria (skullcap)
- cranial base (basicranium)
What is the viscerocranium?
- facial bones that form:
- orbits
- nasal cavities
- upper jaw
- lower jaw (mandible)
What are the bones of the neurocranium and their location?
- frontal (forehead)
- parietal (2)
- temporal (2)
- mastoid process, styloid process, external acoustic meatus
- occipital (back of head)
- external occipital protuberance
- sphenoid (butterfly)
- ethmoid
What are the sutures of the neurocranium and which bones do they split?
- Coronal: frontal and parietal
- Lambdoid: parietal and occipital
- Sagittal: R & L parietal
- Squamous: parietal and temporal
What are the intersections of the cranial sutures?
- Bregma: sagittal and coronal
- Lambda: lambdoid and sagittal
- Pterion: frontal, parietal, temporal, sphenoid
- Asterion: parietal, occipital, temporal
- Nasion: frontal and nasal bones
What occurs if the pterion is fractured?
Fracture to pterioni may tear the middle meningeal artery leading to an epidural hematoma
Where are the Glabella? Vertex? Inion?
- Glabella: most anterior part of forehead
- Vertex: superiormost post of neurocranum
- Inion: most prominent point of external occipital protuberance
What bones make up the anterior fossa?
- frontal bone
- ethmoid bone
- part of sphenoid bone (lesser wing)
What bones make up the middle fossa?
Sphenoid (greater wing/body) Temporal bone (squamous and petrous part)
What bones make up the posterior fossa?
Temporal bone (petrous part) Occipital bone
What holes are in the anterior fossa?
cribriform plate (ethmoid)
What holes are in the middle fossa?
All sphenoid
- optic foramen
- superior orbital fissure
- foramen rotundum/ovale/spinosum/lacerum
What holes are in the posterior fossa?
- internal acoustic meatus (temporal)
- jugular foramen (between temporal and occipital)
- hypoglossal canal (occipital)
- foramen magnum (occipital)
What are the characteristics for the sphenoid bone?
- it is a key in cranial skeleton
- it articulates with 8 bones
- has a central body, 2 wings laterally and 2 processes inferiorly
Where is the pituitary gland?
within the hypophysis in the sella turcica (body of sphenoid)
What are the bones of the viscerocranium?
- lacrimal (2)
- nasal (2)
- zygomatic (2)
- palatin (2)
- inferior nasal conchae (2)
- mandible
- vomer
What bones form the orbit wall?
- frontal bone
- ethmoid bone
- lacrimal
- maxilla
- palatine
- zygomatic
- sphenoid (greater/lesser wing)
- superior/inferior orbital fissure
What bones form the nasal cavity?
- nasal
- maxillae
- inferior nasal conchae
- ethmoid (middle/superior nasal conchae and perpendicular plate)
- vomer
What are the other important holes in the face?
- Supraorbital notch/foramen (frontal): V1 trigeminal exits (ophthalmic nerve) supplying forehead sensory
- Infraorbital foramen (maxilla): V2 trigeminal exits supplying mid face sensory
- Mental foramen (mandible): V3 trigeminal supplying mandible sensory