CRANIAL & FACIAL BONES ANATOMY Flashcards
How many cranial bones?
-8 bones: Frontal, Occipital, Right Parietal, Left Parietal, Ethmoid, Sphenoid, Right temporal, Left temporal
“Eight Osseous Parts Form The Skull”
How many facial bones?
-14 bones: Nasal(right and left), Lacrimal(right and left), Maxillary(right and left), Zygomatic(right and left), Palatine(right and left), Inferior nasal conchae(right and left), Vomer, Mandible
“My Mandible Chews Nine Very Large Zucchini Pizzas”
What are the Joints of the skull and what type of tissue are they?
Coronal suture- fibrous
Sagittal suture- fibrous
Squamous suture- fibrous
Lambdoidal suture- fibrous
Temporomandibular- synovial(hinge and gliding)
Alveolar sockets- fibrous
Atlantooccipital- synovial(ellipsoidal)
Coronal Suture
Between frontal and parietal bones
Sagittal suture
Between the parietal bones, contains Bregma which is the junction of coronal and Sagittal sutures
Squamosal suture
Between the temporal and parietal bones, contains the Pterion which is the junctions of the parietal bones, squamous suture, and greater wing of the sphenoid
Lambdoidal suture
Between the occipital and parietal bones, contains the Lambda which is the junction of lambdoidal and sagittal sutures
Frontal bones
-Forms the forehead (vertical section)
-Frontal eminence
-Frontal sinuses*
-Roof of the nasal and orbital cavities (horizontal section)
-Supraorbital margins
-Superciliary arches
-Glabella*
-Ethmoid Notch
-Articulates with the right and left parietals, sphenoid, and ethmoid bones
The ethmoidal notch recieves the _________ _______ of the ethmoid bone
Cribiform plate
The orbital plates of the horizontal portion of the frontal bone are separated by a notch called the
Ethmoidal notch
Ethmoid bone
-Smallest cranial bone that forms most of the bony area between the nasal cavity and orbit
-Cribiform (horizontal plate)
-Perpendicular plate
-Labyrinths
Ethmoid bone: Cribiform plate
-Olfactory foramina for olfactory nerves
-Crista galli: cone shaped process that is attachment for falx cerebri
Ethmoid bone: Perpendicular plate
Forms superior portion of the nasal septum (with nasal spine from frontal bone)
Ethmoid bone: Labyrinths
- Labyrinths: form part of orbits and lateral walls of nasal cavity
-Ethmoid sinuses or air cells
-Superior and Middle Nasal Conchae
Sphenoid bone
Butterfly shaped bone that spans the width of the skull and forms part of the cranial floor
-Body
-Lesser Wings
-Greater Wings
-Pterygoid Processes
-Sella Turcica:houses pituitary gland
-Tuberculum sellae: anterior wall
-Anterior clinoid processes
-Dorsum sellae: posterior wall
-Posterior clinoid processes
Sphenoid: Pterygoid Processes
-Pterygoid Processes: extend inferiorly and curve laterally
-Medial and lateral laminae
-Pterygoid hamulus: hook shaped process
Temporal bone
-Forms the lateral wall on each side and base of the cranium
-Squamous portion
-Tympanic portion
-Styloid process
-Zygomatic process
-Petromastoid portion
Temporal bone: Zygomatic Process
Joins with temporal process of zygomatic bone to form the cheek bone
Temporal bones: External Acoustic Meatus
Temporal bones: Mastoid process
Contains air cells
Temporal bones: Petromastoid portion
-aka Petrous pyramids, pars petrosa
-Contains organs for hearing and balance
-Petrous apex: most medial portion
-Petrous ridge: upper border of petrous portion
-Internal acoustic meatus (IAM): transmits vestibulocochlear and facial nerves
Petrous ridges will be used to determine proper positioning for
skull, sinus, and facial bones projections
Occipital bone
Forms the posterior half of the base of the cranium
-Squama
-Occipital condyles
-Foramen magnum
-Basilar portion
Occipital Bone: EXTERNAL Occipital Protuberance (Inion)
-Prominent, midline projection
-Radiographic landmark
Occipital bone: INTERNAL Occipital Protuberance (IOP)
The occipital condyle articulate with
C1
Occipital bone: Basilar portion
-Curves anteriorly and superiorly to join with the body of the sphenoid
-Clivus: junction between dorsum sellae(on the sphenoid) and basilar portion
Parietal bones:
-Pair of bones that form the most superior and lateral walls of the cranium
-Parietal eminence: widest point
-Vertex: most superior point
More pictures of the Cranium
Facial bones: Nasal (2)
-Form superior bony wall (called the bridge of the nose) of the nasal cavity
-Nasal bones articulate in the MSP
-Nasal bones articulate with the perpendicular plate of the ethmoid bone at their posterosuperior surface
-Nasal bones articulate with the frontal bone above and with the maxillae on the sides
Facial bones: Lacrimal (2)
-Smallest bones in the skull
-Lacrimal bones form lacrimal fossae which accommodate the lacrimal sacs
-Each lacrimal bone contains a lacrimal foramen through which a tear duct passes
-Articulate with the frontal and ethmoid cranial bones and the maxilla and inferior nasal concha facial bones
-Seen on PA and Lateral projections
Facial bones: Maxillary (2)
-Largest immovable bones of the face
-Articulate with all other facial bones EXCEPT mandible
-Articulate with frontal and ethmoid bone of the cranium
-Form part of the lateral walls, most of the floor of the nasal cavity
-Form part of the floor of the orbital cavities, 3/4ths of the roof of the mouth
-Zygomatic processes articulate with the zygomatic bones to help create the prominences of cheek bones
-Body of maxillae contain pyramidal cavity called the Maxillary Sinus which empties into the nasal cavity
-An infraorbital foramen is located under each orbit and serves as a passage through which the infraorbital nerve and artery reach the nose
-At the inferior borders, maxillae have a thick spongy ridge called the alveolar process which supports the roots of the teeth
-At the anterior MSP, the junction where the maxillae join to form a pointed, forward-projecting process called the anterior nasal spine this midpoint of this prominence is called the acanthion
Facial bones: Zygomatic (2)
-Form prominence of cheeks and a part of the side wall and floor of the orbital cavities
-The temporal process(posteriorly extending) unites with the zygomatic process of the temporal bone to form the zygomatic arch
-Zygomatic bones articulate with the frontal bone superiorly, zygomatic process of the temporal bone at the sides, maxilla anteriorly, and sphenoid bone posteriorly
Facial bones: Palatine (2)
-L shaped bones composed of vertical and horizontal plates
-Horizontal plates articulate with the maxillae to complete posterior 1/4th of the bony palate or roof of mouth
-Vertical plates of the palatine bones extend upward between the maxillae and the Pterygoid processes of the sphenoid bone in the posterior nasal cavity
-The superior tips of the vertical portions of the palatine bones assist in forming the posteromedial bony orbit
Facial bones: Inferior nasal conchae (2)
-Extend diagonally and inferiorly from the lateral walls of the nasal cavity at approximately its lower 1/3rd
-Have a scroll like appearance
-The 3 nasal conchae project into and divide lateral portion of the respective side of the nasal cavity into superior, middle, and inferior Meatus and covered with a mucus membrane
-Upper 2 nasal conchae are processes of the ethmoid bone
Facial bones: Vomer
-Sits in the MSP of the floor of the nasal cavity and forms the inferior part of the nasal septum
-The superior part of its anterior border articulates with the perpendicular plate of the ethmoid bone; its posterior border is free
Facial bones: Mandible
• Largest and densest bone of the face
• Body is the horizontal portion
• Rami (2) vertical portion
• Body and Rami unite to form the gonion
