Bones Of The Head (cranial & facial) Flashcards
large membranous and unossified gaps between the bones of the skull, in the fetus and newborn
Fontanelles
The cranium serves to
Enclose brain
Provide attachment sites for some head and neck muscles
Cranium is divided into
cranial vault
base
The skull contains smaller cavities
Middle and inner ear cavities
Nasal cavity
Orbits
Air-filled sinuses
Paired cranial bones
Parietal
Temporal
Unpaired cranial bones
Frontal
Occipital
Sphenoid
Ethmoid
Forms superciliary arches
Frontal bones
Internally, it contributes to the anterior cranial fossa
Frontal bones
Articulates posteriorly with the parietal bones via the coronal suture
Frontal bones
Major markings of the frontal bones
- supraorbital margins
- anterior cranial fossa
- frontal sinuses (internal and lateral to the glabella)
Form most of the superior and lateral aspects of the skull
Parietal bones
Four sutures mark the articulations of the parietal bones
Coronal
Squamous
Sagittal
Lambdoid
located where parietal bones meet the frontal bone
Coronal suture
where each parietal bone meets a temporal bone inferiorly
Squamous suture
where right and left parietal bones meet superiorly
Sagittal suture
where the parietal bones meet the occipital bone posteriorly
Lambdoid suture
Forms the posterior portion of the cranium and cranial base
Occipital bone
Articulates with the temporal bones and parietal bones
Occipital bone
Forms the posterior cranial fossa;
Foramen magnum located at its base
Occipital bone
These structures pass thru the foramen magnum
Brainstem
CN XI
Vertebral Arteries
Meninges
CN XII passes here
Hypoglossal canal
features and structures of the occipital bone
Occipital condyles Hypoglossal canal External occipital protuberance Superior nuchal lines Inferior nuchal lines
Lie inferior to parietal bones; Lie inferior to parietal bones
Temporal bones
Specific regions of temporal bone
squamous
temporal
petrous
mastoid
CNs VII &VIII
Internal auditory meatus
Major markings of the temporal bones
zygomatic process styloid process mastoid process mandibular fossa middle cranial fossa internal auditory meatus external auditory meatus
Spans the width of the middle cranial fossa
Sphenoid bone
Forms the central wedge that articulates with all other cranial bones
Sphenoid bone
The sphenoid bone consists of
- central body
- greater wings
- lesser wings
- pterygoid processes
Major markings of the sphenoid bone
- sella turcica
- hypophyseal fossa
- pterygoid processes
Major openings of the sphenoid bone
superior orbital fissure - CNs III, IV, V1, VI & Ophthalmic Veins
foramina rotundum - CN V2
foramina ovale - CN V3
foramina spinosum - Middle Meningeal Artery
optic canal - CN II
CNs III, IV, V1, VI & Ophthalmic Veins
Superior orbital fissure
CN V2
foramina rotundum
CN V3
foramina ovale
Middle meningeal artery
foramina spinosum
CN II
optic canal
Deepest of the skull bones; Lies between nasal and sphenoid
bones
Ethmoid bone
Forms most of the medial bony region between the nasal cavity and orbits; olfactory foramina
Ethmoid bone
CN I
Olfactory foramina
Major markings of the ethmoid bone
- cribriform plate
- crista galli
- perpendicular plate
- nasal conchae
- ethmoid sinuses
Unpaired facial bones
vomer
mandible
Paired facial bones
maxillae zygomatics nasals lacrimals palatines inferior conchae
the largest and strongest facial bone
Mandible
Two main parts of the mandible
Horizontal body
Two upright rami
2 groups:
- Cranial bones
2. Facial bones
Major markings of the mandible
coronoid process
mandibular condyle
alveolar margin
mandibular foramina
mental foramina
Medially fused bones that make up the upper jaw and the central
portion of the facial skeleton
Maxillary bones
Articulate with all other facial bones except the mandible
Maxillary bones
largest paranasal sinuses
maxillary sinuses
Forms part of the inferior orbital fissure
Maxillary bone
Major markings of the maxillary bones
- palatine process
- frontal process
- zygomatic processes
- alveolar margins
- inferior orbital fissure
- maxillary sinuses
Irregularly shaped bones that form the prominences of the cheeks and the inferolateral margins of the orbits
Zygomatic bones
thin medially fused bones that form the bridge of the nose
Nasal bones
contribute to the medial walls of the orbit and contain a deep groove called the lacrimal fossa that houses the lacrimal sac
lacrimal bones
two bone plates that form portions of the hard palate, the posterolateral walls of the nasal cavity, and a small part of the orbits
Palatine bones
forms the inferior part of the nasal septum
vomer
Thin, curved bones that project medially to form the lateral walls of the nasal cavity
inferior nasal conchae
