Radiographic Skull

Question 1

What are the 8 bones in the skull?

Answer 1

1 frontal
2 parietal
2 temporal
1 sphenoid
1 ethmoid
1 occipital

Question 2

What’s a suture?

Answer 2

Joins the bones of the cranium

Question 3

What are the junctions of the brain?

Answer 3

Bregma
Lambda
Pterion
Asterion

Question 4

What’s joined by the bregma junction?

Answer 4

Coronal and sagittal sutures

Question 5

What’s joined by the lambda junction?

Answer 5

Lambdoidal and sagittal sutures

Question 6

What’s joined by the pterion?

Answer 6

Parietal bone, temporal bone and sphenoid bone

Question 7

What’s joined by the asterion?

Answer 7

Occipital bone, parietal bone, and temporal bone

Question 8

What’s a fontanel and which age group are they found in?

Answer 8

• Soft spot in the skull of an infant
• Found in infants
• The bones in a newborn infant are not fully developed

Question 9

Where are the 7 fontanels located?

Answer 9

• 2 in the sagittal plane
• Anterior fontanel at bregma
• Posterior fontanel at lambda
• 2 at pterion (called sphenoidal fontanel)
• 2 at asterion (mastoid fontanel)

Question 10

What are the 3 cranial fossae?

Answer 10

Anterior
Middle
Posterior

Question 11

What’s in the anterior cranial fossa?

Answer 11

• Frontal bone
• Ethmoid bone
• Lesser wing of sphenoid bone
• Frontal lobes of brain

Question 12

What’s in the middle cranial fossa?

Answer 12

• Body of sphenoid and temporal bones
• Pituitary gland
• Hypothalamus
• Temporal lobes

Question 13

What’s in the posterior cranial fossa?

Answer 13

• Occipital bone
• Temporal bone
• Cerebellum
• Brainstem

Question 14

What’s formed by the frontal bone?

Answer 14

• Forehead
• Roofs of the orbit
• Most of the anterior part of cranial floor
• Contains frontal sinuses

Question 15

What’s the parietal eminence?

Answer 15

Smooth rounded surface that forms the widest part of the cranium

Question 16

What are the 4 parietal borders and their articulations?

Answer 16

Superior = Parietal bone (forms sagittal suture)

Inferior = Sphenoid and temporal bones
(forms squamous suture)

Anterior = Frontal bone
(coronal suture)

Posterior = Occipital bone (lambdoidal suture)

Question 17

What is the zygomatic arch and where is it found?

Answer 17

Cheek bones

Found as a zygomatic process that runs anterior on the bone

Question 18

What’s on the inferior portion of the temporal bone?

Answer 18

• Mandiublar fossa that will articulate with the mandible to form the temporomandibular joint (TMJ)

Question 19

Where is the mastoid portion of the temporal lobe located?

Answer 19

Posterior and inferior to the External Auditory Meatus (EAM)

Question 20

What is the mastoid portion of the temporal lobe?

Answer 20

• Contains mastoid process, which contains several air cells

- Site of muscle attachment

Question 21

What is the purpose of the Internal Audtiory Meatus (IAM)

Answer 21

Opening through which the facial and vestibulocochlear nerves pass

Question 22

What is the petrous portion of the temporal bones

Answer 22

Triangular part that houses the middle and inner ear

Contains carotid foramen

Question 23

What is the occipital bone?

Answer 23

• Forms posterior part and most of base of cranium

Question 24

What is the purpose of the foramen magnum?

Answer 24

Allow the brainstem to travel through

Question 25

Where are the occipital condyles and what are their purpose?

Answer 25

- Either side of the foramen magnum | - To allow head movement

Question 26

What is the purpose of the external occipital protuberance?

Answer 26

Attachment site of the nuchal ligament

Question 27

What are the 4 occipital articulations?

Answer 27

1. Parietal bones at lambdoidal suture 2. Temporal bones 3. Sphenoid 4. C1 Atlas forms Atlanta-occipital joints

Question 28

Which bone articulates with all other cranial bones?

Answer 28

Sphenoid bone

Question 29

What is the purpose of the sphenoid sinus?

Answer 29

Drains into the nasal cavity

Question 30

What is the function of the sella turcica, and where is it located?

Answer 30

Located on the superior body of the sphenoid | Houses the pituitary gland

Question 31

Define lesser wing of the sphenoid

Answer 31

- Projects laterally from the upper anterior part of the body - Forms part of the orbit

Question 32

Define greater wing of the sphenoid

Answer 32

- Extends laterally from the body and form the anterolateral floor of the cranium

Question 33

Where is the optic foramina found and what is its function?

Answer 33

Found between the greater and lesser wing Allow optic nerve and ophthalmic arteries to pass

Question 34

Where is the ethmoid bone found?

Answer 34

- Midline in the anterior part of the cranial floor - Medial to the orbits - Anterior to sphenoid - Posterior to the nasal bones

Question 35

Which 4 structures does the ethmoid bone form

Answer 35

1. Part of the anterior wall of the cranial floor 2. Superior portion of the nasal septum 3. Medial wall of the orbits 4. Superior side wall of the nasal cavity

Question 36

What is the cribriform plate? | ethmoid bone

Answer 36

- Superior part of the ethmoid | - Contains the olfactory foramina through which the olfactory nerve passes

Question 37

What is the crista galli? | ethmoid bone

Answer 37

Process on the superior aspect that serves as an attachment site for membranes

Question 38

What are the lateral masses? | ethmoid bone

Answer 38

Compose most of the wall between the nasal cavity and orbits

Question 39

What is the perpendicular plate? | ethmoid bone

Answer 39

Forms septum of nose

Question 40

What is the function of the superior and medial nasal concha? (ethmoid bone)

Answer 40

Increase mucus membrane surface area in the nasal cavities

Question 41

What is the function of the ethmoid sinuses?

Answer 41

Provide lubrication (mucus) to the inner nose

Question 42

What is the zygomatic arch?

Answer 42

- Formed by zygomatic process of temporal bone and temporal process of the zygomatic bone (side of cheekbone)