CRANIAL & FACIAL BONES ANATOMY

Question 1

How many cranial bones?

Answer 1

-8 bones: Frontal, Occipital, Right Parietal, Left Parietal, Ethmoid, Sphenoid, Right temporal, Left temporal

“Eight Osseous Parts Form The Skull”

Question 2

How many facial bones?

Answer 2

-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”

Question 3

What are the Joints of the skull and what type of tissue are they?

Answer 3

Coronal suture- fibrous
Sagittal suture- fibrous
Squamous suture- fibrous
Lambdoidal suture- fibrous
Temporomandibular- synovial(hinge and gliding)
Alveolar sockets- fibrous
Atlantooccipital- synovial(ellipsoidal)

Question 4

Coronal Suture

Answer 4

Between frontal and parietal bones

Question 5

Sagittal suture

Answer 5

Between the parietal bones, contains Bregma which is the junction of coronal and Sagittal sutures

Question 6

Squamosal suture

Answer 6

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

Question 7

Lambdoidal suture

Answer 7

Between the occipital and parietal bones, contains the Lambda which is the junction of lambdoidal and sagittal sutures

Question 8

Frontal bones

Answer 8

-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

Question 9

The ethmoidal notch recieves the _________ _______ of the ethmoid bone

Answer 9

Cribiform plate

Question 10

The orbital plates of the horizontal portion of the frontal bone are separated by a notch called the

Answer 10

Ethmoidal notch

Question 11

Ethmoid bone

Answer 11

-Smallest cranial bone that forms most of the bony area between the nasal cavity and orbit
-Cribiform (horizontal plate)
-Perpendicular plate
-Labyrinths

Question 12

Ethmoid bone: Cribiform plate

Answer 12

-Olfactory foramina for olfactory nerves
-Crista galli: cone shaped process that is attachment for falx cerebri

Question 13

Ethmoid bone: Perpendicular plate

Answer 13

Forms superior portion of the nasal septum (with nasal spine from frontal bone)

Question 14

Ethmoid bone: Labyrinths

Answer 14

• Labyrinths: form part of orbits and lateral walls of nasal cavity
  -Ethmoid sinuses or air cells
  -Superior and Middle Nasal Conchae

Question 15

Sphenoid bone

Answer 15

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

Question 16

Sphenoid: Pterygoid Processes

Answer 16

-Pterygoid Processes: extend inferiorly and curve laterally
-Medial and lateral laminae
-Pterygoid hamulus: hook shaped process

Question 17

Temporal bone

Answer 17

-Forms the lateral wall on each side and base of the cranium
-Squamous portion
-Tympanic portion
-Styloid process
-Zygomatic process
-Petromastoid portion

Question 18

Temporal bone: Zygomatic Process

Answer 18

Joins with temporal process of zygomatic bone to form the cheek bone

Question 19

Temporal bones: External Acoustic Meatus

Answer 19

Question 20

Temporal bones: Mastoid process

Answer 20

Contains air cells

Question 21

Temporal bones: Petromastoid portion

Answer 21

-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

Question 22

Internal Acoustic Meatus (IAM)

Answer 22

transmits vestibulocochlear and facial nerves

Question 23

Petrous ridges will be used to determine proper positioning for

Answer 23

skull, sinus, and facial bones projections

Question 24

Occipital bone

Answer 24

Forms the posterior half of the base of the cranium
-Squama
-Occipital condyles
-Foramen magnum
-Basilar portion

Question 25

Occipital Bone: **EXTERNAL Occipital Protuberance (Inion)**

Answer 25

-Prominent, midline projection -Radiographic landmark

Question 26

Occipital bone: **INTERNAL Occipital Protuberance (IOP)**

Answer 26

Question 27

The occipital condyle articulate with

Answer 27

C1

Question 28

Occipital bone: Basilar portion

Answer 28

-Curves anteriorly and superiorly to join with the body of the sphenoid -**Clivus**: junction between dorsum sellae(on the sphenoid) and basilar portion

Question 29

Parietal bones:

Answer 29

-Pair of bones that form the most superior and lateral walls of the cranium -Parietal eminence: widest point -Vertex: most superior point

Question 30

More pictures of the Cranium

Answer 30

Question 31

Facial bones: Nasal (2)

Answer 31

-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

Question 32

Facial bones: Lacrimal (2)

Answer 32

-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

Question 33

Facial bones: Maxillary (2)

Answer 33

-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**

Question 34

Facial bones: Zygomatic (2)

Answer 34

-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

Question 35

Facial bones: Palatine (2)

Answer 35

-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

Question 36

Facial bones: Inferior nasal conchae (2)

Answer 36

-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

Question 37

Facial bones: Vomer

Answer 37

-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

Question 38

Facial bones: Mandible

Answer 38

• Largest and densest bone of the face • Body is the horizontal portion • Rami (2) vertical portion • Body and Rami unite to form the gonion