Skull

Question 1

How many cranial bones

Answer 1

8

Question 2

Cranial bones are divided into which 2 groups?

Answer 2

Calavaria and Floor

Question 3

Bones of the cranial vault are composed of

Answer 3

Two plates of compact tissue separated by an inner layer of spongy tissue (diploe)

Question 4

Bones of the cranium are formed by

Answer 4

Sutures

Question 5

What are the sutures

Answer 5

Coronal, Sagittal, Squamosal, and Lambdoidal

Question 6

Coronal Suture

Answer 6

Found between frontal and parietal bones

Question 7

Sagittal Suture

Answer 7

Found at the top of the head between the two parietal bones

Question 8

Junction of the coronal and sagittal sutures

Answer 8

Bregma

Question 9

Squamosal Suture

Answer 9

Found between the temporal and parietal bones

Question 10

Lambdoidal Suture

Answer 10

Found between the occipital and parietal bones

Question 11

Lambda

Answer 11

Junction of the lambdoidal and sagittal sutures

Question 12

Pterion

Answer 12

Junction of the parietal bone, Squamosal Suture, and greater wing of the sphenoid found on the lateral aspect of the skull

Question 13

Asterion

Answer 13

Junction of the occipital bone, parietal bone, and mastoid portion of the temporal bone

Question 14

Cranial floor is divided into three regions:

Answer 14

Anterior, middle, and posterior cranial fossae

Question 15

The anterior cranial fossa extends from

Answer 15

The anterior frontal bone to the leader wings of the sphenoid

Question 16

The middle cranial fossa accommodates

Answer 16

The temporal lobes and extends from the lesser wings of the sphenoid bone to the apices of petrous portions of the temporal bones

Question 17

The superior surface of the sphenoid bone presents

Answer 17

Deep depressions called the sella turcica, which contains the pituitary gland

Question 18

Mesocephalic

Answer 18

Average skull shape

Question 19

Bradycephalic Skull

Answer 19

Shorter and wider skull

Question 20

Doliochocephalic Skull

Answer 20

Long and narrow skull

Question 21

Lateral Position

Answer 21

• Side of interest closest to the IR
• MSP parallel to the plane of the IR
• IOML perpendicular to the front edge of the IR but parallel with the long axis
• Interpupillary line perpendicular to IR

Question 22

Where does the CR enter in a lateral?

Answer 22

Perpendicular, 2 inches above EAM.

Question 23

What does a lateral image show?

Answer 23

Superimposed halves of the cranium. The sella turcica (in profile), anterior clinoid processes, dorsum sellae, and posterior clinoid processes.

Question 24

How do you tell there’s no tilt or rotation in a lateral?

Answer 24

Superimposed orbital roofs and greater wings of the sphenoid, superimposed mastoids, EAM, and TMJ

Question 25

PA Projection

Answer 25

- OML perpendicular to the IR | - MSP perpendicular

Question 26

Where does the CR enter for a PA?

Answer 26

Perpendicularly, directed to exit the nasion

Question 27

Where does the CR enter for Caldwell Method

Answer 27

Same as PA. Directed to exit nasion at an angle of 15 degrees caudad.

Question 28

To show the superior orbital fissures, what do you do with the CR in a PA?

Answer 28

Direct the CR through the midorbits at an angle of 20-25 degrees caudad.

Question 29

Where are the petrous portions in a PA projection with a perpendicular central ray?

Answer 29

Inside the orbits

Question 30

Where are the petrous portions in the Caldwell method?

Answer 30

Into the lower one third of the orbits

Question 31

What structures are seen on a PA?

Answer 31

Posterior ethmoidal air cells, crista galli, frontal bone, and frontal sinuses. Caldwell shows anterior ethmoidal air cells as well.

Question 32

AP Projection/AP Axial

Answer 32

- MSP and OML perpendicular to the IR - CR perpendicular or directed at the nasion at an angle of 15 degrees cephalad. - Orbits are considerably magnified

Question 33

Towne Method (AP Axial)

Answer 33

- MSP and OML perpendicular to IR | - IR’s upper margin at top of vertexg

Question 34

Townes CR (AP Axial)

Answer 34

- Perpendicular to the foramen magnum at a caudal angle of 30 degrees to the OML or 37 to the IOML - Enters approximately 2 and a half inches above the glabella and passes through EAM

Question 35

AP Axial structures

Answer 35

Image of the petrous pyramids, the posterior portion of the foramen magnum, dorsum sellae and the posterior clinoid process projected within the foramen magnum

Question 36

PA Axial (Haas)

Answer 36

- Used for demostrating sellar structures projected within foramen magnum on patients who cannot be adjusted accordingly for Townes (AP axial) - MSP and OML perpendicular to IR

Question 37

Haas CR

Answer 37

Directed at a cephalad angle of 25 degrees to the OML to enter 1 1/2 inches below the inion and exits 1 1/2 inches above the nasion

Question 38

Haas Structures

Answer 38

Shows the occipital region of the cranium and symmetrical petrous pyramids and the dorsum sellae and posterior clinoid processes within the foramen magnum