Skull-Part 1 Flashcards
How many bones are in the skull?
22
How many crainial bones are there? What are they?
8
Ethmoid
Frontal
Occipital
Parietal (x2)
Sphenoid
Temporal (x2)
How many facial bones are there? What are they?
14
Inferior Nasal Conchae (x2)
Lacrimal (x2)
Mandible
Maxilla (x2)
Nasal (x2)
Palatine Bone (x2)
Vomer
Zygomatic Bones (x2)
What is the Largest facial bone
Mandible
What are the two portions of the Mandible?
Horizontal and vertical portions
What is the angle of the Mandible created by? What is another term for angle?
Angle created by the junction of two portions (horizontal and vertical) is termed the gonion
What part of the mandible contains the alveolar processes?
The curved horizontal portion contains alveolar processes that receive the roots of the teeth of the lower jaw.
What is another name for the horizontal portion of the mandible?
The body
Where do the mental foramina extend through?
Through the body of the mandible
What does the mental foramina allow passage for?
Allows passage of the mental artery and nerve.
What is the vertical portion of the mandible called?
Is called the ramus
What are the 2 processes of the ramus? Where are these processes located?
-coronoid process & condyloid process (condyle)
-At superior portion
What are the processes of the ramus separated by?
Separated by a concave surface called the mandibular notch.
What is the coronoid process an attachment site for?
Attachment site for the temporalis and masseter muscles
What does the condyloid process articulate with?
The mandibular fossa of the temporal bone
What does the articulation of the condyloid process and the mandibular fossa of the temporal bone form?
Forms the temporomandibular joint (TMJ).
T/F
The masseter muscle is a facial muscle that plays a major role in the chewing of solid foods.
True
What is the shape of the masseter muscle?
The muscle is shaped like a parallelogram
What does the masseter muscle connect?
Connects the mandible and the cheekbone (zygomatic arch).
What is the largest immovable facial bone?
Maxilla
Where do the Maxillary bones fuse?
At the midline
What does the anterior fusion of the maxillary bone form?
Forms a pointed process termed the anterior nasal spine (acanthion)
What is the opening in the anterior aspect of the maxilla called? What structures does it transmit?
Called the infraorbital foramen – transmits the infraorbital nerve and blood vessels.
What forms the upper part of the mouth and the anterior ¾ of the hard palate?
Pair of maxillary bones
What bones does the maxilla articulate with?
Articulates with every bone in the face except the mandible.
What term is this describing?
Pocket of air lined by epithelium that produces mucosal secretions, which drain into the nasal cavity via the middle meatus of the lateral nasal wall.
The Sinus
T/F
Palatine process forms the roof the mouth
True
What makes up the hard palate?
palatine + palatine process of maxilla
What is the Posterior ¼ of the hard palate made of?
Made up of the horizontal process of the palatine bone
How many sets of palatine bones are there?
2 sets of palatine bone
What is the shape of the palatine bones?
L shaped
Where are the palatine bones located?
Located in the posterior aspect of the nasal cavity between the maxilla and the pterygoid process of the sphenoid
What are the two portions of the palatine bones?
Horizontal + Perpendicular portions
Where does the horizontal portion off the palatine bone join with the palatine process? What does it form?
Horizontal portions joins anteriorly with the palatine process of the maxilla to form the hard palate
What bone contributes to part of the lateral wall of the nasal cavity?
The vertical portion of the palatine bone
T/F
The vertical portion forms part of the lateral wall of the orbit
False; The vertical portion forms part of the MEDIAL wall of the orbit
T/F
The zygoma articulates with the maxilla
True
What structure runs anteriorly to the zygoma?
maxillary process
What does the frontal process of the zygoma extend towards?
Towards the frontal bone
T/F
The maxillary process extends anteriorly
True
The zygomatic process of the maxilla and the maxillary process do not connect
False; The maxillary process extends anteriorly to connect with the zygomatic process of the maxilla
What forms the zygomatic arch?
anteriorly, by the temporal process of the zygomatic bone; - posteriorly, by the zygomatic process of the temporal bone
What does the nasal septum divide the nasal cavity into?
Midline structure that divides the nasal cavity into right and left nostril
What makes up the nasal septum?
Perpendicular plate of the ethmoid bone and vomer and the nasal cartilage (3)
What forms the floor of the nasal cavity?
The maxilla and the palatine bone forms the floor of the nasal cavity
T/F
The vomer contributes to the medial wall of the nasal cavity
True
T/F
Nasal bones articulate with the frontal bone
True
What bone is the smallest of the cranial bones?
Ethmoid
Where is the Ethmoid bone located within the cranial fossa?
Located in the anterior cranial fossa
What are the sections of the Ethmoid?
Horizontal + vertical + 2 lateral masses
What is the Horizontal portion of the Ethmoid known as?
Cribriform plate
T/F
The vertical portion of the ethmoid Consists of two grooves (depressions) called the vomer.
False; Cribriform plate (horizontal)
Where does the cribriform plate sit?
Sits in the ethmoid notch of the frontal bone
What structures does the Cribriform plate contain?
Contains many foramina for the passage of the olfactory nerves
Where does the Crista galli stem from? In what direction does it extend?
From the midline and projects superiorly
What does the Crista galli act as an attachment for?
Acts as an attachment for the falx cerebri (Dural connective tissue that anchors the brain)
T/F
The vertical portion (perpendicular plate) projects inferiorly from the cribriform plate to form a portion of the bony nasal septum
True
T/F
The lateral masses of the ethmoid incorporate the orbital plates which contribute to the lateral orbit
False; The lateral masses of the ethmoid incorporate the orbital plates which contribute to the MEDIAL orbit
What do the lateral masses of the ethmoid contain?
They contain the ethmoid air cells/ethmoid sinuses
T/F
The ethmoid bones also forms the lateral walls of the upper nasal cavity.
True
What part of the nasal cavity and the orbit does the ethmoid bone contribute to?
Lateral wall of nasal cavity
Medial wall of the orbit
T/F
Palatine and maxilla contribute to the roof of the mouth but the floor of the nasal cavity
True
What structure Projects medially from the lateral masses of the ethmoid?
Two scroll shaped processes called the superior and middle nasal conchae (turbinates)
What structure Projects laterally from the lateral masses of the ethmoid?
The uncinate process
What is the Single, midline bone that forms the roof and the lateral walls of the upper nasal cavity, the upper portion of the nasal septum, and contributes to the medial wall of the orbits?
The ethmoid bone
T/F
Around the middle nasal conchae is called the middle nasal meatus
True
Fill in the ?
The ethmoid bone also forms a small area of the midline in the floor of the anterior cranial fossa. This region also forms the ? of the underlying ?
The ethmoid bone also forms a small area of the midline in the floor of the anterior cranial fossa. This region also forms the NARROW ROOF of the underlying NASAL CAVITY.
T/F
The Inferior nasal conchae is NOT part of the ethmoid bone
True; Considered to be 2 independent bones of the face
Where are the Inferior nasal conchae located?
Lower portion of the nasal cavity
What part of the nasal cavity does the Inferior nasal conchae contribute to?
Contributes to the lower lateral wall of the nasal cavity
What is the largest nasal conchae?
Inferior nasal conchea
What are the four paranasal sinuses?
Frontal
Ethmoid
Sphenoid
Maxillary
T/F
There are air cells within the maxillary sinus
True
What is the Superior border of the maxillary sinus?
Orbital floor
What is the inferior border of the maxillary sinus?
Maxillary alveolus
What is the order of drainage from the maxillary sinus?
Ostium → Infundibulum → Hiatus semilunaris → Middle meatus
What is the opening into the infundibulum called?
The ostium
T/F
There Air cells within the frontal sinus
True
What is the Anterior border of the frontal sinus?
Frontal bone
What is the Superior & Posterior border of the frontal sinus?
Floor of the anterior cranial fossa
What is the inferior border of the frontal sinus?
Orbital roof
What is the order of drainage from the frontal sinus?
Frontal recess→ which connects to the Middle meatus (Frontal sinus-frontal recess-middle nasal meatus)
What is the lateral border of the ethmoid sinus?
Lamina papyracea
What is the Posterior border of the ethmoid sinus?
Sphenoid sinuses
What are the steps of drainage for the anterior ethmoid sinuses?
Ant. Air cells → recess of hiatus semilunaris → middle meatus
What are the steps of drainage for the posterior ethmoid sinuses?
Post air cells → Sphenoethmoidal recess → superior meatus
What are the two groups of the paranasal sinuses?
Anterior and posterior groups
What sinuses are part of the anterior group?
Frontal, Maxillary and Anterior air cells.
T/F
Frontal, Maxillary and Anterior air cells all drain into the middle meatus
True
What sinuses are part of the posterior sinuses?
Sphenoid & Posterior ethmoidal air cells
T/F
The Sphenoid & Posterior ethmoidal air cells drains into the sphenoethmoidal recess and then into the superior meatus
True
What is the superior border of the sphenoid sinus?
Sella turcica
What is the Inferior border of the sphenoid sinus?
Nasopharynx
What is the anterior border of the sphenoid sinus?
Ethmoid sinus
What is the posterior border of the sphenoid sinus?
Clivus
What are the steps of drainage from the sphenoid sinus?
Sphenoethmoidal recess → Superior meatus
What bone is this describing?
Located directly posterior to the nasal bones and maxilla
Lacrimal bones
Where are the lacrimal bones located in relation to the orbit?
Located on the medial surface of the orbit
How many lacrimal bones are there?
2 lacrimal bones
What is the anterior border of the lacrimal bone?
FP of the maxilla
What is the posterior border of the lacrimal bone?
Posteriorly: Anterior ethmoid cells
What is the Superior border of the lacrimal bone?
Frontal bone
What is the inferior border of the lacrimal bone?
Inferior nasal conchae
What 7 bones does the orbit consist of?
PLES Feed My Zebra
P: Palatine
L: Lacrimal
E: Ethmoid
S: Sphenoid
F: Frontal
M: Maxilla
Z: Zygoma
T/F
Maxilla contributes to the floor of the orbit and the medial wall
True
What is the globe of the eye divided into?
Globe of the eye divided into anterior and posterior compartments
Where is the Anterior compartment of the eye located? What is it filled with?
Anterior to the lens, filled with acqueous humor.
What compartment of the eye is larger?
Posterior
T/F
The posterior compartment of the eye is located behind the lens
True
What does the posterior compartment of the eye contain?
Contains a jelly like substance called the vitreous humor.
Where does the optic nerve begin in relation to the globe of the eye?
The optic nerve commences on the posterior surface of the globe
Where does the optic nerve exit?
Courses posteromedially to exit the orbit via the optic canal.
What is the optic nerve surrounded by?
retroorbital fat
What is the location of the palatine bone in relation to the roof of the mouth?
Posterior portion of the roof of the mouth.
What does the palatine bone form?
Forms the bottom/ lateral of the nasal cavity and part of the orbital floor.
What does the palatine bone articulate with?
Sphenoid, Ethmoid, Maxillae, INC, Vomer and opposite Palatine bones.
What does the inferior nasal conchae form?
Thin bones that form the sides of the nasal cavity.
What does the inferior nasal conchae articulate with?
Ethmoid, palatine , Lacrimal, and Maxillae.
Where is the vomer located?
On the floor of the nasal cavity and part of the nasal septum
What is the function of the vomer?
Separates the nasal cavities into left and right sides.
What does the vomer articulate with?
Sphenoid, Ethmoid, Maxillae and Palatine
What does the zygoma articulate with?
Articulates with the frontal, maxilla, temporal and sphenoid bones.
Where are the lacrimal bones located?
Posterior and lateral to nasal bone
What do the lacrimal bones articulate with?
Frontal superiorly, Ethmoid superiorly, Maxilla anteriorly and INC
What does the mandible form?
Forms the chin and sides of face.
What does the mandible articulate with?
Temporal bone
What does the maxilla form?
Forms lower parts of the orbits.
What does the maxilla articulate with?
All facial bones except mandible
What do the nasal bones form?
Form the bridge and roof of the nose.
What do the nasal bones articulate with?
Frontal superiorly, Ethmoid posteriorly, Maxilla laterally and opposite nasal.
