Skull Flashcards
Define Neurocranium + where is it derived from?
- -the portion of the skull that surrounds the brain
- - derived from head mesoderm
Membranous neurocranium (i.e., calvarium) is formed from:
– forms by intramembranous ossification
Cartilaginous neurocranium (i.e., base of skull)– forms by
intracartilaginous ossification
Viscerocranium forms the and is derived from…
- the portion of the skull that forms the bones of the face
- derived from neural crest
Membranous viscerocranium
(e.g., upper and lower jaw)–forms by intramembranous ossification
Cartilaginous viscerocranium
(e.g., hyoid bone, middle ear ossicles, persistent cartilages of the neck)forms by intracartilaginous ossificatio
Name the neurocranium bones:
Frontal (unpaired) * Ethmoid (unpaired) Sphenoid (unpaired) Occipital (unpaired) Temporal (paired) * Parietal (paired) * Yellow * = Calvarium or skullcap
Name the viscerocranium bones:
Viscerocranium: 15 bones Mandible (unpaired) Maxilla (paired) Ethmoid (unpaired) Inferior nasal cocha (paired) Vomer (unpaired) Zygomatic (paired) Palatine (paired) Nasal (paired) Lacrimal (paired)
Name bones of the calvarium:
What type are they?
Describe the bones:
What do the inner surfaces of them form?
Frontal, Parietal (2), Occipital, Temporal (2)
• “Flat bones”– really cupped with concave and convex surfaces
• 2 “Tables”(“diploie”) – sheets of inner and outer compact bone separated by a layer of spongy bone
• Inner surfaces form anterior, middle (with sphenoid bone), and posterior cranial fossae
Describe the frontal bone
Two parts
• “Squamous part”forms the forehead of the calvarium
• Forms the floor of the anterior cranial fossa
(“orbital part”; the roof ofthe orbit).
• Contains a paranasal sinus(frontal sinus)
Review topographical features of the frontal bone:
Glabella and Supraciliary ridge Nasion (point of contact withnasal bones) Pterion Superior and inferior temporal lines and temporal fossa
Vertex
- superior-most part of the calvaria, along sagittal sutures
Bregma
- where sagittal and coronal sutures converge – anterior fontanelle
Glabella
– at midline on frontal bone right btwn the eyebrows
Lambda
– where lambdoid and sagittal sutures converge – posterior fontanelle
Inion
- external occipital protuberance, on occipital bone
Asterion
– where lambdoid and temporal sutures converge
Nasion
- where frontal contacts nasal bones
Pterion
- where frontal, parietal and temporal converge over the medial meningeal a.
Superior temporal line
– on calvarium (frontal and parietal specifically)
Inferior temporal line
– on calvarium (frontal and parietal specifically)
Supraciliary ridge
– eyebrow ridge
Pharyngeal tubercle
– just anterior to foramen magnum on occipital bone
External occipital protuberance
- inion
Styloid process
– attachment site of many muscles, temporal bone, looks like stylus
Mastoid process
– posterolateral to styloid process, temporal bone
Zygoma
– prominence of the cheek, from zygomatic and temporal bones
Sagittal suture
– separates parietal bones
Lambdoid suture
- separates occipital from parietal bones
Coronal sutur
e - separates frontal from parietal bones
Name bones that form the Nasal cavity
– vomer, inferior nasal concha, palatine, lacrimal, ethmoid
Name bones that form the Oral cavity
Oral cavity – mandible, maxilla, palatine, sphenoid?
Name the neurocranial bones that contribute to the calvarium a
of frontal, parietal and temporal
Name bones that contribute to the cranial base.
occipital, sphenoid, ethmoid and petrous portion of temporal
Describe the Clivus
Clivus – where occipital and sphenoid meet just adjacent to foramen magnum
Describe the parietal bone
• Flat bone with one part – the “squamous part”
• Forms the wall and roof of the
middle cranial fossa
Describe the occipital Bone (maybe don’t need to know this, from lecture slide)
• Forms most of the wall of the posterior cranial fossa • Squamous part • Occiput part • Foramen magnum • Clivus (together with sphenoid bone)
Internal features:
• Hypoglossal foramen
• Jugular foramen separates occipital and temporal bones
• Internal occipital crest and protuberance
• Groove for the transverse venous sinus
Topographic features:
- Pharyngeal tubercle
- Hypoglossal foramen
- Jugular foramen
- Occipital condyle
- Foramen magnum
- External occipital crest (nuchal ligament attaches here)
- Inferior nuchal line
- Superior nuchal line
- External occipital protuberance (inion)
State which of the above topographic features corresponds to the following fontanelles of the neonatal skull.
anterior fontanelle
anterior fontanelle - bregma
State which of the above topographic features corresponds to the following fontanelles of the neonatal skull.
posterior fontanelle
posterior fontanelle - lambda
State which of the above topographic features corresponds to the following fontanelles of the neonatal skull.
mastoid fontanelle
mastoid fontanelle - asterion
State which of the above topographic features corresponds to the following fontanelles of the neonatal skull.
sphenoidal fontanelle
sphenoidal fontanelle - pterion
Describe what is meant by the term “paranasal sinus,”
Sinuses near nose and that connect in some way to it
Name the 3 unpaired and 1 set of paired bones that contain these sinuses.
Frontal sinus – in frontal bone near superciliary ridge
Sphenoid sinus – housed by sella turcica
Ethmoidal air cells – space between orbital plates and nasal concha
Maxillary sinus – in maxilla in frontal area, paired
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Hypophysial fossa
– unpaired, the saddle part of sella turcica of sphenoid bone
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Anterior cranial fossae
Calcarium inner surfaces form anterior, middle (with sphenoid bone), and posterior cranial fossae
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Middle cranial fossae
Calcarium inner surfaces form anterior, middle (with sphenoid bone), and posterior cranial fossae
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Oral Cavity
– posterior to mouth, unpaired
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Posterior cranial fossa -
Calcarium inner surfaces form anterior, middle (with sphenoid bone), and posterior cranial fossae
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Orbits
- contain eyeballs, paired
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Temporal fossae
– superior to zygomatic arch, paired
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Nasal cavities
– posterior to nose, paired
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Cranial vault
- consists of the anterior, middle and posterior cranial fossae
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Infratemporal fossae
– inferior to zygomatic arch of temporal bone, paired
Describe (in general terms) the following spaces within, and on the surface, of the skull.
State which spaces are paired, and which ones are unpaired.
Pterygopalatine fossae
– narrow space btwn palatine bones and sphenoid bone, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Superior orbital foramen
– frontal, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Optic canal
– sphenoid, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Foramen spinosum
– sphenoid, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Foramen rotundum
– sphenoid, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Foramen ovale
– sphenoid, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Foramen magnum
– occipital, unpaired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Foramen lacerum
– sphenoid, paired
State which bone (or bones) contain the following foramena, and state which foramena are paired and which ones are unpaired.
Jugular foramen
– occipital, paired
Describe the osteological features of the mandible.
• Mental protuberance on the external chin
• Mental spines on the internal chin
• Coronoid process
• Condylar process
(“head of the mandible”; articular process of
the TMJ)
• Ramus of the mandible
• Horizonal process (“body of the mandible”) holding
the alveolar processes of the lower teeth
• Angle of the mandible
Describe the temporomandibular joint, as well as the movements of the jaw associated with this synovial joint.
- Articular disc of the TMJ
- The condylar head moves anteriorly as the jaw opens (under the control of the lateral pterygoid muscle)
- Elevation (close mouth)–Temporal, masseter, medial pterygoid mm.
- Depression (open mouth)–lateral pterygoid m.
- Protrusion–Lateral pterygoid m. (masseter, medial pterygoid mm.)
- Retrusion–Temporal, masseter mm.
- Lateral movements–Temporal (on same side as movement), Pterygoids (on the opposite side as movement), masseter
Name the ligaments that limit depression of the jaw.
• Two ligaments limit the opening of the jaw
- Stylomandibular ligament
- Sphenomandibular ligamen
What traverse the superior orbital fissure?
III,VI,V1,VI, superior opthalmic vein and sympathetics
What traverse the foramen rotundum?
V2
What traverse the foramen ovale?
V3
What traverse the foramen spinosum?
middle meningeal cessels
What traverse the carotid groove?
internal carotid a.
