Procedures Chapter 12 Skull

Front 1

This is an important landmark because it corresponds to the floor of the anterior fossa of the cranial vault.

Back 1

supraorbital groove

Front 2

Which four cranial bones does the frontal bone articulate with?

Back 2

Right and Left Parietals
Sphenoid
Ethmoid

( the frontal bone also articulates with 8 facial bones)

Front 3

superior rim of each orbit

Back 3

supraorbital margin

Front 4

The supraorbital notch is a small hole within the _____________ slightly medial to it's midpoint.

Back 4

supraorbital margin

Front 5

The frontal tuberosity is _______ to the supraorbital groove on each side of the squamous portion of the frontal bone.

Back 5

superior

Front 6

Which parts of the frontal bone are seen from an inferior aspect?

Back 6

The horizontal or orbital portion

Front 7

Each orbital plate is separated from the other by the _____ _____.

Back 7

ethmoidal notch

Front 8

smooth raised prominence between the eyebrows just above the bridge of the nose.

Back 8

glabella

Front 9

The slight depression above each eyebrow

Back 9

supraorbital groove (SOG)

Front 10

The widest portion of the entire skull is located between the _____ _____.

Back 10

parietal tubercles (eminences)

Front 11

The greater wings of the sphenoid are ______ & ______ in relation to the parietals.

Back 11

inferior and anterior

Front 12

Each parietal articulates with ___ cranial bones. Name them.

Back 12

5 cranial bones

frontal
occipital
temporal
sphenoid
& the opposite parietal

Front 13

This part of the occipital bone forms most of the back of the head and is superior to the external occipital protuberance (inion).

Back 13

squamous portion

Front 14

On an AP axial projection of the skull the dorsum sellea is above the foramen magnum, which mistake has occurred and how is it fixed?

Back 14

Underangulation has occurred, increase the CR angle.

Front 15

On an AP axial projection of the skull, C1 has been projected inside of the foramen magnum? how did this happen and how do you fix it?

Back 15

overangulation
decrease the angle

Front 16

Which structures should be shown on a AP axial projection of the skull?

Back 16

-occipital bone
-petrous pyramids
-foramen magnum with dorsum sellae and posterior clinoids inside the shadow.

Front 17

What structures must be shown on a lateral skull?

Back 17

Superimposed cranial halves, sella turcica, dorsum sellae, and clinoids

Front 18

How can rotation be assessed on a lateral skull radiograph?

Back 18

symmetric vertical bilateral structures '

1.) Mandibular rami
2.) mastoid processes
3.) EAM's

Front 19

How can tilt be assessed on a lateral skull?

Back 19

symmetric horizontal structures

1.) orbital roofs
2.) mandibular bodies

Front 20

just anterior to the EAM is the _______ , into which the mandible fits to form the TMJ

Back 20

temporomandibular fossa

Front 21

A slender bony projection inferior to the mandible and anterior to the EAM.

Back 21

Styloid process

Front 22

Thin upper portion of the temporal bone that forms part of the wall of the cranium.

Back 22

squamous portion

Front 23

The most vulnerable portion of the entire skull to fracture.

Back 23

squamous portion

Front 24

This part of the temporal bone houses the organs of hearing and equilibrium.

Back 24

petrous portion

Front 25

The upper border or ridge of the petrous pyramids is commonly called the _____ ______ or petrous apex.

Back 25

petrous ridge

Front 26

Each temporal bone is divided into _____ parts. Name them.

Back 26

Three

1.)squamous portion
2.)mastoid portion (posterior to EAM)
3.)Petrous portion (petrous pyramids)(pars petrosa)

Front 27

The single occipital bone resides between the paired _____ bones.

Back 27

temporal bones

Front 28

thickest and most dense part of the cranium

Back 28

petrous portion

Front 29

______ corresponds to the level of an important external landmark, the TEA. (top of the ear attachment)

Back 29

petrous ridges

Front 30

serves to transmit the nerves of hearing and equilibrium.

Back 30

internal acoustic meatus

Front 31

An opening or orifice near the center of the petrous pyramids on the posterior surface just superior to the jugular foramen.

Back 31

internal acoustic meatus

Front 32

Which three bones does the temporal bone articulate with?

Back 32

parietal
occipital
sphenoid

Front 33

forms the anchor for all eight cranial bones

Back 33

sphenoid bone

Front 34

hypophysis cerebri is also the ______________

Back 34

pituitary gland

Front 35

The dorsum sellae is best seen from a ______ view.

Back 35

lateral

Front 36

A slightly depressed area located on the sphenoid bone that forms a base of support for the pons & basilar artery

Back 36

clivus

Front 37

The lesser wings of the sphenoid are triangular and nearly horizontal, and end medially at the ______ .

Back 37

anterior clinoid processes

Front 38

The _________ are somewhat larger and more spread apart than the __________.

Back 38

anterior clinoids ; posterior clinoids.

Front 39

The optic groove leads to the _______, which ends as the ______ foramen.

Back 39

optic canal; optic foramen

Front 40

The superior orbital fissures are slightly ______ & ______ to the optic foramina

Back 40

lateral and posterior

Front 41

Why are deformities of the sella turcica so important?

Back 41

it is often the only clue that a lesion exsists intracranially.

Front 42

The sphenoid articulates with ____ other cranial bones.

Back 42

7

Front 43

Projecting superiorly from the cribiform plate is the _____ _____.

Back 43

crista galli

Front 44

The _____ contain the ethmoid air cells.

Back 44

lateral labyrinths (masses)

Front 45

The ethmoid articulates with two cranial bones, the ____ & ____.

Back 45

frontal & sphenoid

Front 46

Sutures are classified as ____ joints, therefore they are synarthrodial (immovable).

Back 46

fibrous

Front 47

The anterior end of the sagittal suture is termed the ______

Back 47

bregma

Front 48

The posterior end of the sagittal suture is termed the ________

Back 48

lambda

Front 49

The _______ are points at the junction of the parietals, temporals, and the greater wings of the sphenoid.

Back 49

pterions

Front 50

The _______ are posterior to the ear where the squamosal and lamboidal sutures meet.

Back 50

asterions

Front 51

The cranial sutures do not completely close until about year _____ or ____.

Back 51

12 or 13 --- some may not completely close until adulthood.

Front 52

in early life the _____ & _____ are not bony structures but are soft spots and are known as the anterior and posterior fontanels.

Back 52

bregma & lambda

Front 53

Which fontanel is the largest?

Back 53

Anterior fontanel

Front 54

The anterior fontanel is ___ cm wide and _____ cm long.

Back 54

2.5 cm wide
4 cm long

Front 55

The anterior fontanel does not completely close until about _____ .

Back 55

18 months of age

Front 56

The sphenoid fontanel is the _____ in an adult.

Back 56

pterion

Front 57

The mastoid fontanel is the ______ in an adult.

Back 57

asterion

Front 58

sutural or wormian bones are most often found in the _______ suture.

Back 58

lambdoidal suture

Front 59

The shape of the average skull is termed ______

Back 59

masocephalic

Front 60

For an average mesocephalic skull the _____ is between 75% and 80% of the _____.

Back 60

width ; length

Front 61

The short broad head is termed ________

Back 61

brachycephalic

Front 62

the long narrow head is called ________

Back 62

dolichocephalic

Front 63

The width of the ________ type of skull is 80% or greater than the length.

Back 63

brachycephalic

Front 64

The width on the ____ type of skull is less than 75% of the length.

Back 64

dolichocephalic

Front 65

In the average shaped, mesocephalic head, the petrous pyramids form an angle of _____.

Back 65

47 degrees

Front 66

The ______ is the small cartilaginous flap that covers the opening of the ear.

Back 66

targus

Front 67

The external portion of the ear

Back 67

auricle or pinna

Front 68

the junctions of the upper and lower eyelids

Back 68

canthi

Front 69

junction of the two nasal bones and the frontal bone

Back 69

nasion

Front 70

refers to the lower posterior angle on each side of the jaw or mandible.

Back 70

angle or gonion

Front 71

prominent bump or protuberance at the inferoposterior portion of the skull.

Back 71

external occipital protuberance

Front 72

Which skull positioning line is used for the SMV projection ? Does it need to be aligned perpendicular or parallel?

Back 72

IOML ( infraorbitomeatal line)

aligned parallel

formed by connecting the infraorbital margin to the EAM.

Front 73

What would you look for on an SMV image that has already been performed to tell if it's correctly positioned.

Back 73

1.) mandibular condyles projected anterior to the petrous pyramids
2.) frontal bone and mandibular symphysis superimposed
3.) mandibular condyles parallel
4.) equal distance bilaterally from mandibular condyles to lateral border of skull.

Front 74

Where is the CR for the SMV?

Back 74

1 1/2 inches inferior to the mandibular symphysis or midway between gonions.

Front 75

The PA axial Haas method is an alternative for what other skull projection?

Back 75

AP axial towne

Front 76

Where should the CR exit for the PA axial Haas method?

Back 76

1 1/2 inches superior to the nasion

Front 77

What is the CR angle for the PA Haas method?

Back 77

25 degrees cephalad

Front 78

where should the posterior clinoids be located for the PA axial Haas position?

Back 78

within the foramen magnum

Front 79

Where does the CR exit when performing the PA 0 degree skull projection?

Back 79

glabella

Front 80

The _____ projection is performed when the frontal bone is the primary area of interest.

Back 80

PA projection 0 degrees

Front 81

The PA axial Caldwell alternate projection with a 25 - 30 degree CR angle provides better visualization of what structures?

Back 81

superior orbital fissures
foramen rotundum
inferior orbital rim region

Front 82

What is the CR angle for the PA axial Caldwell method?

Back 82

15 degrees caudad

Front 83

where is the PA axial caldwell centered the exit?

Back 83

the nasion

Front 84

The petrous pyramids are projected in the lower 1/3 of the orbit for the _____ projection

Back 84

PA axial caldwell 15 degree caudad

Front 85

The _______ connects the glabella to a point at the anterior aspect of the alveolar process of the mandible

Back 85

GAL glabelloalveolar line

Front 86

where does the CR enter for the AP axial towne mathod?

Back 86

2 1/2 inches above the glabella

Front 87

which bones does the occipital bone articulate with

Back 87

both parietal
both temporal
sphenoid
atlas

Front 88

Which skull classification applies a 54 degree angle between the midsagittal plane and long axis of the pars petrosa

Back 88

brachycephalic

Front 89

which skull classification does the angle between the MSP and petrous ridge equal 40 degrees

Back 89

dolichocephalic

Front 90

Reids base line is an older term for the ______

Back 90

IOML

Front 91

best imaging modality for a cranial bleed caused by trauma

Back 91

CT

Front 92

which two projections of the cranium project the dorum sellae within the foramen magnum?

Back 92

AP axial towne
PA axial Haas