Skull Osteology Flashcards
What allows anatomical comparison of skulls?
The Frankfurt Horizontal (FH) plane
What does this black line illustrate?
the Frankfurt Horizontal plane
The Frankfurt Horizontal plane is defined by which 3 points?
Right and left porion points
Left orbitale
Where are the right and left porion points located?
at top of each external acoustic meatus
Where is the left orbitale located?
At bottom of left orbit
What are the 5 standard perspectives that Frankfurt Horizontal skulls are viewed from, anatomical and lame terminology?
- Norma verticalis - from above
- Norma lateralis - from side
- Norma occipitalis - from behind
- Norma frontalis - from front
- Norma basilaris - from below
How many bones contribute to the versatility of the skull?
23 at least
3 ways in which a large number of bones contributes to the versatility of the skull?
More joints enables:
- Babies with bigger heads to be born (sutures overlap)
- Facilitates complex growth patterns (primary cartilaginous/synchondroses joints)
Increase resilience (suture lines stop fracture spreading further)
What can the skull be divided into, 2 things?
Neurocranium (brain case)
viscerocranium (facial skeleton)
What is this part of the skull called?
Neurocranium
What is this part of the skull called?
Viscerocranium
The neurocranium can be divided into what 2 parts?
Membranous neurocranium (Dermatocranium)
Cartilaginous neurocranium (chondrocranium)
Which part of the neurocranium Is responsible for forming the majority of the neurocranium?
Membranous (Dermatocranium)
The membranous neurocranium is composed of which bones?
Flat bones of the skull cap e.g. frontal, parietal
How is the membranous neurocranium formed?
By intramembranous ossification
Membrane bone role?
Protective
The cartilaginous neurocranium is composed of which bones?
Bones of the base of the skull e.g. ethmoid, sphenoid
How is the cartilaginous neurocranium formed?
By endochondral ossification
Endochondral bone role?
Supportive
where is the infratemporal fossa?
below the zygomatic arch in a lateral view of the skull
ridges on the occipital bone are caused by?
muscle attachment
The flat, thin part of the occipital bone is called
squamous part
The mastoid process is caused by
attachment of the sternocleidomastoid muscle
what does the sternocleidomastoid muscle do?
allows the head to turn from side to side
The hard palate is formed from what 4 bones?
Right maxilla
Left maxilla
Right palatine
Left palatine
What are the 5 design features of the adult skull?
- Lightness
- Strength
- Keeping airway open
- Warming & humidifying air breathed in through nose
- Supporting muscles involved in chewing & swallowing
How is the lightness of the skull optimised? 4 things
- Diploe
- Orbits
- Cavities
- Paranasal sinuses
What is diploe?
A meshwork of trabecular spicules between an outer and inner thick layer of cortical bone.
How is the strength of the skull maximised? 5 things
- Near-spherical shape of neurocranium
- Suture joints
- Crumple zones in viscerocranium (Le Fort fractures)
- The buttress system
- Orbital rims protect eyeballs
What are the two design features of the neonatal skull to facilitate birth?
- Deformable head (“moulding”)
- Minimal development of inessential parts
How are babies heads deformable? 3 things
- Wide sutures
- Fontanelles (soft spots)
- Thin, deformable bones of the neurocranium
What is a fontanelle?
Membranous areas that havn’t turned into bone
Name two parts of the neonatal skull that are minimally developed? 2 things
- Small jaws - liquid diet - no chewing
- Small nose - no sense of smell
What is the mode of ossification for the diploe of the Dermatocranium?
Intramembranous ossification
What is intramembranous ossification?
Bone that’s forming from within a membrane
What is endochondral ossification?
bone forming from a cartilaginous template
What are the two types of forces to the facial skeleton?
- Traumatic forces
- Masticatory forces
What are the two types of traumatic force to the facial skeleton?
- Blows to the mid-face (maxillary region)
- Blows to the lower face (mandible)
What is the risk from a blow to the mid-face (maxillary region)
Maxillae pushed into the base of the skull piercing the neurocranium and damaging the brain
How is the risk from a blow to the mid-face (maxillary region) prevented? 2 things
Bones of the maxillae are thin so crumple, dissipating the force
Le Fort fracture pattern, fractures separate from the base of the skull
What is the risk from a blow to the lower face (mandible)?
Mandibular condyle is driven up through the base of the skull via its temporomandibular articulation
How is the risk from a blow to the lower face (mandible) prevented? 2 things
Mandible is dense so can absorb forces
Mandible fractures in specific places before damage to neurocranium
How does the mandible deal with masticatory forces?
Is thick, strong bone that spreads occlusal forces across itself
How does the maxilla deal with masticatory forces?
Thin, hollow bone that dissipates occlusal forces away from itself and onto the neurocranium via the buttress system
what is a buttress?
dense area of bone along which forces travel
how many craniofacial buttresses?
3
what are the 3 craniofacial buttresses called?
frontonasal buttress
zygomatic buttress
pterygoid buttresses
where is the frontonasal buttress?
past nasal bone into frontal bone
where is the zygomatic buttress?
past zygomatic arch into the neurocranium
where are the pterygoid buttresses?
posterior upper dentition along the lines of the pterygoid plates of sphenoid into the neurocranium
how many Le Fort fractures of the facial skeleton?
3
what does the Le Fort I fracture of the facial skeleton separate?
upper dentition from the facial skeleton
what does the Le Fort II fracture of the facial skeleton separate?
majority of maxilla separated from the facial skeleton
what does the Le Fort III fracture of the facial skeleton separate?
viscerocranium separated from the neurocranium
which craniofacial buttress is this?
frontonasal buttress
which craniofacial buttress is this?
zygomatic buttress
which craniofacial buttress is this?
Pterygoid buttresses
which Le Fort fracture is this?
Le Fort I
which Le Fort fracture is this?
Le Fort II
which Le Fort fracture is this?
Le Fort III
which Le Fort fracture is this?
Le Fort III
the mandible can fracture at what 5 areas?
- Body
- Angle
- Ramus
- Coronoid process
- Condylar process of the mandible
name this cranial bone?
frontal
name this cranial bone?
parietal
name this cranial bone?
temporal
name this cranial bone?
nasal
name this cranial bone?
sphenoid
name this cranial bone?
zygomatic
name this cranial bone?
maxilla
name this cranial bone?
mandible
name this cranial bone?
lacrimal
name this cranial bone?
vomer
name this cranial bone?
parietal
name this cranial bone?
occipital
name this cranial bone?
temporal
name this cranial bone?
zygomatic
name this cranial bone?
mandible
name this cranial bone?
maxilla
name this cranial bone?
nasal
name this cranial bone?
sphenoid
name this cranial bone?
frontal
name this cranial bone?
parietal
name this cranial bone?
occipital
name this cranial bone?
temporal
name this cranial bone?
sphenoid
name this cranial bone?
maxilla
name this cranial bone?
mandible
name this cranial bone?
maxilla
name this cranial bone?
zygomatic
name this cranial bone?
sphenoid
name this cranial bone?
temporal
name this cranial bone?
occipital
name this cranial bone?
palatine
name this cranial bone?
frontal
name this cranial bone?
spenoid
name this cranial bone?
temporal
name this cranial bone?
occipital
name this cranial bone?
parietal
name this cranial bone?
ethmoid
name this cranial bone?
inferior nasal concha
name this cranial bone?
ethmoid
name this cranial bone?
hyoid
what 3 bones are in the base of the skull
sphenoid
temporal
occipital
what 5 bones are in the calvaria of the skull
frontal
parietals
temporals
sphenoid
occipital
what 5 bones make up the face of the skull
frontal
zygomatics
nasals
lacrimals
maxillae
what is the calvaria of the skull
roof and sides
name this suture
coronal suture
name this suture
squamosal suture
name this suture
zygomatico-frontal suture
name this suture
zygomatico-maxillary suture
name this suture
lambdoid suture
name this joint
temperomandibular joint
name this suture
zygomatico-temporal suture
name this suture
sagittal suture
name this suture
lambdoid suture
name this suture
squamosal suture
name this suture
basilar suture / sphenooccipital synchrondosis
name this part of the occipital bone
occipital condyles
what is the atlanto-occipital joint between
occipital condyles and superior articulating facets of atlas C1
what is the Atlanto-axial joint between
inferior articulating facets of atlas C1 and superior articulating facets of axis C2
what is the infratemporal fossa
area below the zygomatic arch
name this major surface feature
supraorbital foramen/notch
name this major surface feature
supraorbital margin
name this major surface feature
temporal lines
name this major surface feature
temporal fossa
name this major surface feature
mastoid process
name this major surface feature
external acoustic meatus
name this major surface feature
styloid process
name this major surface feature
zygomatic arch
what are neuchal lines?
superior and inferior muscle markings from sternocleidomastoid
name this major surface feature
neuchal lines
name this major surface feature
external occipital protuberance
what bones is the hard palate made up of 4?
2 maxilla
2 palatine
What is the infratemporal fossa?
Area below the zygomatic arch
Name this foraminae
Optic Foramen
Name this foraminae
Superior orbital fissure
Name this foraminae
Foramen rotundum
Name this foraminae
Foramen ovale
Name this foraminae
Foramen spinosum
Name this foraminae
Foramen lacerum
Name this foraminae
Internal acoustic meatus
Name this foraminae
Jugular foramen
Name this foraminae
Hypoglossal canal
Name this foraminae
Foramen magnum
Name this part of the sphenoid
Sella turcica
Name this part of the ethmoid
Cribriform plate
Name this part of the ethmoid
Crista galli
Name this bone
Ethmoid
What’s this part of the interior skull called?
Anterior cranial fossa
What’s this part of the interior skull called?
Middle cranial fossa
What’s this part of the interior skull called?
Posterior cranial fossa
What r these grooves for?
Dural venous sinuses
Name this part of the nasal cavity
Sphenoethmoidal recess
Name this part of the nasal cavity
Superior nasal concha
Name this part of the nasal cavity
Middle nasal concha
Name this part of the nasal cavity
Inferior nasal concha
Name this part of the nasal cavity
Vomer
Name this part of the nasal cavity
Inferior meatus
Name this part of the nasal cavity
Middle meatus
Name this part of the nasal cavity
Superior meatus
Name this part of the nasal cavity
Sphenoidal sinus
Name this bone
Ethmoid
Name this part of the ethmoid
Lamina orbitals
Name this part of the ethmoid
Perpendicular plane
Name this part of the ethmoid
Middle nasal concha
Name this part of the ethmoid
Superior nasal concha
Name this part of the ethmoid
Cribriform plate
Name this part of the ethmoid
Crista galli
Name this part of the ethmoid
Crista galli
Name this part of the ethmoid
Superior nasal concha
Name this part of the ethmoid
Middle nasal concha
Name this part of the ethmoid
Perpendicular plane
Name this bone
Frontal
Name this part of the frontal bone
Supraorbital notch
Name this part of the ethmoid
Orbital plate
Name this part of the ethmoid
Nasal spine
Name this part of the frontal bone
Frontal air sinus
Name this part of the ethmoid
Supraorbital margin
Name this part of the ethmoid
Supraorbital Foramen
Name this part of the frontal bone
Temporal line
Name this bone
Maxilla
Name this part of the maxilla
Zygomatic process/buttress
Name this part of the maxilla
Alveolar process
Name this part of the maxilla
Infraorbital Foramen
Name this part of the maxilla
Incisive canal
Name this part of the maxilla
Palatine process
Name this part of the maxilla
Maxillary sinus
Name this bone
Mandible
Name this part of the mandible
Coronoid process
Name this part of the mandible
Lingula
Name this part of the mandible
Mandibular foramen
Name this part of the mandible
Mylohyoid line
Name this part of the mandible
Alveolar part
Name this part of the mandible
Mental protuberance
Name this part of the mandible
Body
Name this part of the mandible
Gonial angle
Name this part of the mandible
Ramus
Name this part of the mandible
Neck of condyle
Name this part of the mandible
Head of condyle
Name this part of the mandible
Mylohyoid groove
Name this part of the mandible
Coronoid/mandibular notch
Name this part of the mandible
Mental spines
Name this bone
Sphenoid
Name this part of the sphenoid
Greater wing
Name this part of the sphenoid
Spine of sphenoid
Name this part of the sphenoid
Pterygoid hamulus
Name this part of the sphenoid
Sphenoidal sinus
Name this part of the sphenoid
Pterygoid plates
Lateral and medial
Name this part of the sphenoid
Pterygoid canal
Name this part of the sphenoid
Foramen rotundum
Name this part of the sphenoid
Superior orbital fissure
Name this part of the sphenoid
Optic canal
Name this part of the sphenoid
Lesser wing
Name this part of the sphenoid
Greater wing
Name this part of the sphenoid
Superior orbital fissure
Name this part of the sphenoid
Foramen rotundum
Name this part of the sphenoid
Pterygoid plates
Lateral and medial
Name this part of the sphenoid
Body
Name this part of the sphenoid
Pterygoid hamulus
Name this part of the sphenoid
Spine of sphenoid
Name this part of the sphenoid
Lesser wing
Name this part of the sphenoid
Optic canal
Name this part of the sphenoid
Greater wing
Name this part of the sphenoid
Pterygoid plates
Name this part of the sphenoid
Spine of sphenoid
Name this part of the sphenoid
Body
Foramen spinosum
Name this part of the sphenoid
Foramen ovale
Name this part of the sphenoid
Pterygoid hamulus
Name this part of the sphenoid
Sphenoidal sinus
Name this part of the sphenoid
Greater wing
Name this part of the sphenoid
Optic canal
Name this part of the sphenoid
Sella turcica / pituitary fossa
Name this part of the sphenoid
Foramen spinosum
Name this part of the sphenoid
Foramen ovale
Name this part of the sphenoid
Foramen rotundum
Name this part of the sphenoid
Lesser wing
Name this bone
Temporal
Name this part of the temporal bone
Squamous part
Name this part of the temporal bone
Mastoid process
Name this part of the temporal bone
Styloid process
Name this part of the temporal bone
External acoustic meatus
Name this part of the temporal bone
Zygomatic process
Name this part of the temporal bone
Petrous part
Name this part of the temporal bone
Internal acoustic meatus
Name this part of the temporal bone
Zygomatic process
Name this part of the temporal bone
Mandibular fossa
Name this part of the temporal bone
Styloid process
Name this part of the temporal bone
Stylomastoid foramen
Name this bone
Occipital
Name this part of the occipital bone
Occipital condyles
Name this part of the occipital bone
Foramen magnum
Name this part of the occipital bone
Basilar part
Name this part of the occipital bone
Hypoglossal canal
Name this part of the occipital bone
External occipital protuberance
Name this part of the occipital bone
Nuchal lines
Name this part of the occipital bone
Squamous part
Name this bone
Parietal
Name this part of the parietal bone
Parietal eminence
Name this part of the parietal bone
Temporal lines
Name this part of the parietal bone
Meningeal grooves
Name this bone
Hyoid
Name this part of the hyoid bone
Lesser horn
Name this part of the parietal bone
Body
Name this part of the parietal bone
Greater horn
Name this bone
Palatine
Name this part of the palatine bone
Horizontal plate
Name this part of the parietal bone
Pyramidal process
Name this part of the parietal bone
Perpendicular plate
Name this part of the parietal bone
Horizontal plate
Name this part of the palatine bone
Greater palatine Foramen
Name this part of the parietal bone
Lesser palatine Foramen
Name this part of the parietal bone
Pyramidal process
Name this part of the parietal bone
Posterior nasal spine
Name this part of the palatine bone
Lesser palatine Foramen
Name this part of the palatine bone
Posterior nasal spine
Name this part of the palatine bone
Pyramidal process
Name this part of the palatine bone
Greater palatine foramen
Name this part of the parietal bone
Horizontal plate
Name this bone
Zygomatic
Name this part of the zygomatic bone
Frontal process
Name this part of the zygomatic bone
Zygomaticofacial Foramen
Name this part of the parietal bone
Temporal process
Name this part of the parietal bone
Maxillary process
Name this part of the zygomatic bone
Orbital margin
Name this part of the zygomatic bone
Zygomatico-temporal Foramen
Name these sutures? 1thing
Orbital sutures
Name this part of the nasal cavity
Posterior nares
Name this part of the nasal cavity
Anterior nares
What is this called
Pterion
What is this part called?
Ethmoid air cells
Name this fissure
Inferior orbital fissure
What is this part of the temporal bone?
Entrance for carotid canal
What is this part of the temporal bone?
Grooves for middle meningeal arteries
What is this groove on the temporal bone?
Groove for superior petrosal sinus
Name this Foramen of the mandible
Mental Foramen
Name this part of the maxilla
Maxillary tuberosity
What is this?
Lacrimal duct
What is this part of the temporal bone?
Articular tubercle
What does this image show?
Auditory ossicles
Name this auditory ossicle
Malleus
Name this auditory ossicle
Incus
Name this auditory ossicle
Stapes
Name this suture
Frontomaxillary suture
Name this suture
Median palatine suture
What fossa is located here?
Pterygopalatine fossa
What Foramen is this?
Sphenopalatine Foramen
Name this foraminae
Infraorbital Foramen
Which bone is this?
C1 Atlas
Name this part of atlas C1
Anterior arch
Name this part of atlas C1
Vertebral Foramen
Name this part of atlas C1
Transverse process
Name this part of atlas C1
Transverse foramen
Name this part of atlas C1
Posterior arch
Name this part of atlas C1
Superior articular facets for occipital condyles
Name this bone
C2
Axis
Name this part of axis C2
Odontoid process / dens
Name this part of axis C2
Superior articular facets
Name this part of axis C2
Spinous process
Name this part of axis C2
Transverse Foramen
Name this part of axis C2
Transverse process
Name this part of axis C2
Body
Name this bone
C7
Name this part of C7
Spinous process
Name this part of C7
Vertebral foramen
Name this part of C7
Superior articular facet
Name this part of C7
Transverse foramen
Name this part of C7
Transverse process
Name this part of C7
Body
Name this part of C7
Pedicle
Name this part of C7
Lamina
