Chapter 1 Skull & Meninges Flashcards
List bones of cranium: all paired unless with a (1) next to it.
- Frontal (1)
- Temporal
- Parietal
- Occipital (1)
- Ethmoid (1)
- Sphenoid (1)
List bones of the face
- Maxillary
- Zygomatic
- Lacrimal
- Nasal
- Inferior nasal concha
- Palatine
- Mandible (1)
- Vomer (1)
List bones of ossicles of ear
- Malleus
- Incus
- Stapes
In neonates, the frontal bone is in two halves separated by the ___________.
Metopic (interfrontal) suture
Type of tissue of ‘metopic (interfrontal) suture’
Fibrous connective tissue
The metopic suture is usually replaced with bone within _____ but in a minority of individuals may persist into adult life or even throughout life.
6-8 years
Define ‘body’
Main part of the bone
Define ‘processes/plates/spines’
- Bony extensions from body
- For articulations with other cranial bones
- For attachments of muscles or ligaments
e. g. temporal process of zygomatic bone which articulates with the zygomatic process of the temporal bone
e. g. medial & lateral pterygoid plates - for attachment of muscles of pharynx, mastication, soft palate.
Define ‘eminence’
A bony bump or elevation overlying some deep structure e.g. ARCUATE EMINENCE in middle cranial fossa over inner ear (within bone)
Define ‘impressions’
grooves on surface of bone indicating the presence of some overlying soft tissue structure (soft structure usually forms before bone is laid down)
e.g. grooves for middle meningeal artery & its branches inside squamous part of temporal bone
Define ‘meatus’
Relatively large tube like passage way e.g. external acoustic meatus
e.g. groove for cartilagenous part of auditory tube.
Define ‘emissary foramina’
Small openings for smaller vessels. These can be clinically significant e.g. communication between pterygoid venous plexus on outside of the skull & the cavernous sinus on the inside of the skull. Particular foramina can vary in number or can be absent.
Small openings and canals pass through skull for small branches of cranial nerves e.g. chorda tympani - nerve involed in taste
True
Large foramina provide access for?
Major structures such as internal carotid, facial nerve
Cranial nerves and veins need to leave skull, arteries enter skull.
True
Generally nerves and blood vessels develop first and the bone forms later around them.
True
How are sutures named?
Named according to the bones e.g. zygomatico-maxillary, zygomatico-temporal, zygomatico-frontal
What is ‘piriform aperture’
Single opening into nassal cavity. The anterior opening is a single one ON SKULLS because the cartilaginous septum is missing. If you look into the piriform aperture, you will see the bony nasal septum dividing the nose into two nasal cavities (nasal fossae).
Floor of nasal cavities is the ?
Hard palate
Superior, middle and inferior nasal conchae (turbinates) are visible in the nasal cavities.
False, middle and inferior are visible though.
Describe maxilla?
- Body and frontal, zygomatic and alveolar processes are visible anteriorly. The term ‘alveolar process’ is also used to describe the region of the mandible carrying the teeth.
Maxilla also has
- Palatine process which forms part of the hard palate
- Orbital plate which forms part of the floor of the orbit.
List other features of maxilla
- Alveolar canal
- Maxillary tuberosity
- Anterior nasal spine
- Canine eminence
- Canine fossa
- Infraorbital groove and canal
- Maxillary sinus
Define ‘alveolar canal(s)’
Tiny openings on infratemporal surface for posterior superior alveolar nerves
Define ‘maxillary tuberosity’
Bony angle posterior to third molar
Define ‘canine fossa’
Depression on external surface of maxilla supralateral to canine eminence
Define ‘Facial buttresses’
Thick adjoining regions of one or several facial bones which support facial structures - terminology is variable.
what is ‘zygomatic buttress of maxilla’
Inferior border of maxilla running up to zygomaticomaxillary suture.
_______________ cross parietal & temporal bones
Superior and inferior temporal lines
______ bone forms the prominence of the cheek & part of the side wall of the orbit. The frontal process of the zygomer articulates with the frontal bone in the lateral orbital margin.
Zygomatic
The ______________ is usually present at the base of the frontal process of the zygomer. The __________________ is on medial side of frontal process of zygomer. The temporal process of the zygomer articulates with the zygomatic process of the temporal bone to form the ________.
Zygomaticofacial foramen, zygomaticotemporal foramen, zygomatic arch.
______________ is an indentation beneath temporal lines.
Temporal fossa
_____________ is inferior the temporal fossa & medial to zygomatic arch.
Infratemporal fossa
the infratemporal fossa opens medially into _________ beneath orbit.
Pterygopalatine fossa.
Pterygopalatine fossa contains?
Pterygopalatine ganglion
Pterygopalatine ganglion is parasympathetic or sympathetic?
Parasympathetic
Pterygopalatine fossa connects to the nasal cavity via the ___________.
Sphenopalatine foramen.
The opening connecting pterygopalatine fossa with the infratemporal fossa is sometimes called the ___________
Pterygomaxillary fissure
The two _________ are separated by the sagittal suture. At its posterior end, this joins an inverted V-shaped suture called the ________ which separates the parietal bones from the ________.
Parietal bones, lambdoid suture, occipital bone
Floor of anterior cranial fossa?
Floor is orbital part of the frontal bone (roof of the orbit) & lesser wing of the sphenoid.
The two orbital plates of the frontal bone articulate medially with the ____________ which are perforated by small foramina transmitting olfactory nerve filaments from the nose to the cranial cavity.
Cribriform plates of the ethmoids
Define ‘crista galli’
Is the median bony crest that projects superiorly from the cribriform plate (site of attachment of falx cerebri).
The cribriform plate forms part of the roof of the two nasal cavities.
True
Floor of middle cranial fossa?
Floor is body of sphenoid medially (including hypophyseal fossa) & greater wings of sphenoid laterally
Posterolateral to middle cranial fossa are _____________.
Petrous and squamous temporal bones
Trigeminal impression may be recognisable on lateral part of petrous temporal.
False, medial part of petrous temporal
Grooves for branches of _______________ cross thin squamous temporal bone.
Middle meningeal artery
____________ (_______) contains the pituitary gland (hypophysis cerebri). The bony projections overhanging the fossa are ________________.
Hypophyseal fossa (sella turcica), the anterior & posterior clinoid processes.
What is the dorsum sellae?
Bony ridge between posterior clinoid processes.
The __________ bone at the posterior end of the middle cranial fossa encases the organs of hearing and balance
Petrous temporal
List features of middle cranial fossa
- Arcuate eminence
- Trigeminal impression
- Tegmun tympani
Define ‘arcuate eminence’
A bony bump on petrous temporal bone which overlies the superior/anterior semicircular canal of the inner ear
Define ‘trigeminal impression’
An indentation (sometimes) on posteromedial part of petrous temporal marking position of trigeminal ganglion
Define ‘tegmun tympani’
Indented region of bone anterolateral to arcuate eminence (overlies middle ear)
List openings of middle cranial fossa
- Optic canal
- superior orbital fissure
- Foramina rotundum
- Foramen ovale
- Foramen spinosum
- Foramen lacerum