Skull Flashcards
The cranium is composed by:
Neurocranium and Viscerocranium
The neurocranium consists of:
Consists of: dome-like roof → “calvaria” + a floor → “cranial base”
Formed by: 4 singular bones (frontal, ethmoid, sphenoid, and occipital) + 2 sets of bilateral pairs (temporal and parietal)
The viscerocranium consists of:
Consists of: bones surrounding the mouth, nose, and most of the orbits
Cranial base consists of: 15 irregular
3 singular bones (mandible, ethmoid, and vomer) + 6 paired bilateral bones (maxilla, inferior nasal concha, zygomatic, palatine, nasal, and lacrimal)
With which bones does the frontal bone articulate with?
- Inferiorly: nasal, zygomatic, lacrimal, maxila, ethmoid, and sphenoid
- Posteriorly: parietal
With which bones do the zygomatic bones articulate with?
- Superiorly: frontal
- Posteriorly: sphenoid, temporal
- Medially: maxilla
With which bones does the maxilla articulate with?
- Superiorly: frontal
- Laterally: zygomatic
- Posteriorly: palatine, ethmoid, sphenoid, lacrimal
- Medially: nasal, vomer
- Inferiorly: superior teeth in maxillary processes, inferior nasal concha
What are the middle concha?
Curved bony plates that arise from the ethmoid and are located in the superior part of the lateral walls of each nasal cavity
What is the nasal septum composed of?
Vomer and perpendicular plate of ethmoid
Where is the mandible located?
Inferior to temporal bones and maxillary teeth
With which bones do the temporal bones articulate with?
- Superiorly: parietal
- Posteriorly: occipital
- Anteriorly: sphenoid, zygomatic
- Inferiorly: mandible
With which bones do the parietal bones articulate with?
- Inferiorly: temporal, sphenoid
- Posteriorly: occipital
- Anteriorly: frontal
What is the coronal suture?
Fibrous association where frontal and parietal bones meet
What is the sagittal suture?
Fibrous association where right and left parietal bones meet
What is the lambdoid suture?
Fibrous association where occipital and parietal bones meet
What is the bregma
Fibrous association where the sagittal and coronal sutures meet
What is the lambda?
Fibrous association where the sagittal and lambdoid sutures meet
With which bones does the occipital bone articulate with?
- Anteriorly: parietal and temporal, and sphenoid
- Inferiorly: atlas
With which bones does the ethmoid bone articulate with?
- Inferiorly: vomer, maxilla and palatine
- Anteriorly: lacrimals, inferior nasal conchae, and nasals
- Posteriorly: sphenoid
- Anteriorly and laterally: frontal
With which bones does the sphenoid articulate with?
- Superiorly: frontal, parietal, ethmoid
- Posteriorly: temporal, occipital
- Anteriorly: palatine, zygomatic
- Inferiorly: vomer
What are the boundaries of the temporal fossa?
- Superiorly and posteriorly: superior and inferior temporal lines
- Anteriorly: zygomatic and frontal
- Laterally: zygomatic arch
- Inferiorly: infratemporal crest
What are the boundaries of the infratemporal fossa?
- Laterally: ramus of mandible
- Medially: lateral pterygoid plate
- Anteriorly: posterior aspect of maxilla
- Posteriorly: tympanic plate and mastoid and styloid processes of temporal
- Superiorly: inferior surface of the greater wing of sphenoid
- Inferiorly: where medial pterygoid muscle attaches to mandible near its angle
The orbits are formed by…
4 walls and 1 apex
- Superior wall: orbital part of frontal; near apex the lesser wing of sphenoid
- Medial wall: ethmoid + contributions of frontal, lacrimal, sphenoid
- Lateral wall: frontal process of zygomatic + greater wing of sphenoid
- Inferior wall: maxillae, partly zygomatic and palatine
- Apex: located at optic canal in lesser wing medial to superior orbital fissure
What is the sella turcica composed of?
- Tuberculum sellae: slight elevation anteriorly of body of sphenoid
- Hypophysial fossa: saddle-like depression in the middle for the pituitary gland
- Dorsum sellae: posteriorly, formed by squared plate on body of sphenoid
What composes the roof and floor of the temporal fossa?
-Floor: part of frontal, parietal, temporal, greater wing of sphenoid
- Roof: formed by the temporalis fascia
Where is the pterion and what is it?
Location: anterior temporal fossa. superior to midpoint of zygomatic arch
Is a fibrous association between frontal, parietal, temporal, and greater wing of sphenoid
Where is the sella turcica?
It composes the central part of the middle cranial fossa on the body of sphenoid; surrounded by anterior and posterior clinoid processes
What is the origin of temporalis muscle?
- Floor of temporal fossa
- Deep surface of temporalis fascia