Skull 1 Flashcards
How many bones does the human skull consist of?
22 bones (8 cranial, 14 facial) or 29 bones if you include the inner ear bones and hyoid bones
The cranial and facial skull bones are mostly connected together by ______ joints.
Ossified joints
What does the mandible articulate with?
The temporomandibular joint (synovial)
What is the skull divided into?
The skull is divided into the braincase (neurocranium) and the facial skeleton (viscerocranium)
What makes up the neurocranium? (8)
Frontal (1)
Parietal (2)
Temporal (2)
Occipital (1)
Sphenoid (1)
Ethmoid (1)
What makes up the viscerocranium? (14)
Nasal bones (2)
Nasal conchae (2)
Maxillae (2)
Zygomatic (2)
Mandible (1)
Vomer (1)
Palatine (2)
Lacrimal (2)
What are the 2 parts that consist within the neurocranium?
- Skullcap (calvarium)
- Skull base
What are the 3 parts that make up the skullcap?
- Frontal bone
- Parietal bone
- Occipital bone
The 3 main sutures of the calvarium are…
- The coronal suture (between frontal and parietal)
- The sagittal suture (connecting the 2 parietal)
- The lambdoidal suture (running horizontally between the occipital and both parietal)
What 3 bones make up the neurocranium?
- Parietal
- Occipital (squamous portion, squama)
- Mastoid processes of the temporal
What 3 sutures make up the neurocranium?
- Sagittal
- Lambdoid
- Occipitomastoid
What are the 4 fontanelle?
- Anterior fontanelle (1)
- Posterior fontanelle (1)
- Mastoid fontanelle (2)
- Sphenoid fontanelle (2)
What is the significance of the fontanelle?
Indirect assessment of intracranial pressure
Assessment of the newborn growth, hydration and bone ossification status
What is the temporal fossa?
A shallow depression on the side of the skull
What are the 4 boundaries of the temporal fossa?
- Medially (floor of the temporal fossa): Frontal, Parietal, Temporal, Sphenoid, Occipital bones
- Anteriorly: The frontal process of the zygomatic bone, the zygomatic process of the frontal bone
- Superiorly: Superior and inferior temporal lines
- Inferiorly: Zygomatic arch laterally, the infra temporal crest of the greater wing of the sphenoid cavity
What is the pterion?
An H-shaped region on the floor of the temporal fossa
What are the 4 participating bones of the pterion?
- Frontal
- Parietal
- Greater wing of the sphenoid bone
- Squamous part of the temporal bone
What 5 sutures converge at the pterion?
- Coronal
- Spheno-frontal
- Spheno-parietal
- Sphenoid-squamous
- Squamous (temporoparietal)
Where is the pterion weak?
Where the temporal, parietal, frontal, and sphenoid bones intersect
What could a blunt trauma to the head to the pterion?
Could fracture the skull at the pterion, which could rupture the middle meningeal artery resulting in epidural hematoma
What are the 6 boundaries of the infratemporal fossa?
- Anteriorly: The infratemporal surface of the maxilla
- Posteriorly: The tympanic portion of the temporal bone and its styloid process
- Superiorly (roof): The infratemporal crest of the greater wing of the sphenoid, the infratemporal surface of the temporal squama
- Inferiorly (floor): The medial pterygoid muscle
- Medially: The lateral pterygoid plate
- Laterally: The ramps of the mandible
What are the 7 bones in the inferior skull?
- Maxillae
- Palatine bones
- Vomer
- Sphenoid (pterygoid plates and processes, greater wings (infratemporal surface))
- Temporal bones
- Zygomatic bones
- Occipital bone (basilar, condylar, squamous)
What are the 3 sutures of the inferior skull?
- Median palatine
- Transverse palatine
- Occipitomastoid
What are the 8 openings of the inferior skull?
- Nasal choanae (posterior nasal aperture)
- Foramen lacerum
- Formane ovale
- Foramen spinosum
- Cartoid canal
- Jugular foramen
- Foramen magnum
- Condylar canals
