CH_11_Skull and Cranial Bones (SELF-TEST)

35. What passes through the internal acoustic meatus?

nerves for hearing and equilibrium

6.C. List the number of individual bones that articulate with the following cranial bones. TEMPORAL BONE

3 cranial bones 1) parietal 2) occipital 3) sphenoid

45. A. How much central ray angle is required for the AP axial projection (Towne method) for a skull with the IOML perpendicular to the image receptor? 45. B. What is the central ray angle for this same projection with a perpendicular OML?

37° and 30°

26. Match each of the following pathologic indications to the correct definition or description. A. Bone tumor originating in the bone marrow

multiple myeloma

3.5 Match each of the following definitions or characteristics to the correct facial bone. 5. Located anteriorly in medial aspect of orbit

nasal bones

12. The sphenoid sinus lies directly inferior to the _____.

sella turcica

1. Name the 4 bones that make up the cranium floor.

1) Right temporal 2) Left temporal 3) Sphenoid 4) Ethmoid

40. List the three divisions of the bony labyrinth of the inner ear.

1) cochlea "snail shell" 2) vestibule - contains oval window 3) semicircular canals - sense of direction and equilibrium

4. Identify the seven (cranial and facial) bones that form the bony orbit

1) frontal (cranial) 2) sphenoid (cranial) 3) ethmoid (cranial) 4) maxilla (facial) 5) zygoma (facial) 6) lacrimal (facial) 7) palatine (facial)

3. Which four cranial bones articulate with the frontal bone?

1) left parietal 2) right parietal 3) sphenoid 4) ethmoid

40. What CR angulation is used for the AP axial projection of the TMJ with the OML perpendicular to the image receptor?

40° (5° added from 35° ↓ angle; 47° with added 5° from IOML CR)

33. What is the maximum amount of CR angulation that should be used for an axiolateral oblique projection of the mandible?

45° 45° - demonstrates mentum 30° - demonstrates body 10°-15° - general study 0° (True Lateral) - ramus

6.A. List the number of individual bones that articulate with the following cranial bones. PARIETAL BONE

5 Cranial bones 1) frontal 2) occipital 3) temporal 4) sphenoid 5) opposite parietal bone

6.B. List the number of individual bones that articulate with the following cranial bones. OCCIPITAL BONE

6 cranial bones 1) two parietals 2) two temporals 3) sphenoid 4) atlas (1st cervical vertebra)

44. Which two projections of the cranium project the dorsum sellae within the foramen magnum?

A. AP axial projection (Towne method) B. PA axial projection (Haas method)

33. Which of the following middle ear structures is considered the most lateral? A. Malleus B. Incus C. Stapes D. Oval window

A. Malleus →incus(anvil)→stapes (stirrup)→oval window

22. The CR is centered to exit at the level of the ________ for a well-positioned 15-degree PA axial projection of the facial bones. A. Nasion B. Glabella C. Midorbits D. Acanthion

A. Nasion

22. Which of the following terms is defined as the large cartilaginous aspect of the external ear? A. Pinna B. Tragus C. Glabella D. Acanthion

A. Pinna

25. Which of the following positioning errors frequently results in a repeat exposure of a cranial position? A. Rotation B. Incorrect central ray placement C. Flexion D. Extension

A. Rotation (and tilt)

32. Where should the optic foramen be located with a well-positioned "three-point landing" projection?

Accurate positioning projects the optic foramen into the lower outer quadrant of the orbit.

6.D. List the number of individual bones that articulate with the following cranial bones. SPHENOID

Articulates with ALL SEVEN cranial bones 1) frontal 2) right parietal 3) left parietal 4) occipital 5) right temporal 6) left temporal 7) ethmoid

5. What is the name of a prominent landmark (or "bump") found on the external surface of the occipital bone?

External occipital protuberance (inion)

47. To prevent tilting of the skull for the lateral projection of the cranium, the _________line is placed perpendicular to the image receptor.

IPL

24. How much difference in degrees is there between the OML and the IOML? A. 10 degrees B. 7 to 8 degrees C. 3 degrees D. None (They represent the same positioning line.)

B. 7 to 8 degrees

23. Reid's base line is an older term for: A. GML B. IOML C. OML D. GAL

B. IOML

1. The majority of the hard palate is formed by: A. Maxilla B. Palatine bones C. Zygomatic bone D. Mandible

B. Palatine bones

21. Which of the following landmarks corresponds to the highest level of the petrous ridge? A. EAM B. TEA C. Outer canthus D. Acanthion

B. TEA

36. What type of CR angulation should be used for a PA axial projection of the mandible? A. None B. 10 to 15 degrees cephalad C. 20 to 25 degrees cephalad D. 5 degrees cephalad

C. 20 to 25 degrees cephalad

35. How much skull rotation (from the lateral position) toward the image receptor is required for the axiolateral oblique projection specifically for the mentum? A. 10 to 15 degrees B. 30 degrees C. 45 degrees D. None. Keep the skull in the true lateral position.

C. 45 degrees

42. A benign, cystic mass of the middle ear is a(n): A. Acoustic neuroma B. Osteomyelitis C. Cholesteatoma D. Acoustic sarcoma

C. Cholesteatoma

34. Which of the following factors prevents superimposition of the ramus on the cervical spine for the axiolateral oblique mandible projection? A. Angle CR 10 to 15 degrees cephalad B. Have patient open mouth during exposure C. Extend chin D. Rotate head toward IR

C. Extend chin

39. During an orthopantomographic procedure, it is important to keep the _______ positioning line parallel to the floor. A. OML B. AML C. IOML D. GAL

C. IOML (‖ to the floor)

38. Which auditory ossicle attaches to the oval window? A. Malleus B. Incus C. Stapes D. None

C. Stapes

38. Where is the CR centered for an SMV projection of the mandible?

CR ⊕: MSP, IOML ‖ to IR, 1½" inferior to mandibular symophysis

23. Where are the petrous ridges projected for a properly positioned modified parietoacanthial projection?

Correct neck extension demonstrates petrous ridges just inferior to the maxillary sinuses

21. The CR is centered to exit at the level of the __________________________ for a well-positioned parietoacanthial projection. A. Nasion B. Glabella C. Inner canthus D. Acanthion

D. Acanthion

27. Which of the following clinical indications may require a decrease in manual exposure factors? A. Pituitary adenoma B. Linear skull fracture C. Paget's disease D. Multiple myeloma

D. Multiple myeloma (depending on the severity)

29. Which of the following imaging modalities provides an excellent distinction between normal and abnormal brain tissue? A. CT B. MRI C. Ultrasound D. Nuclear medicine

D. Nuclear medicine

2. Which of the following is not an aspect of the maxilla? A. Frontal process B. Body C. Zygomatic process D. Ramus

D. Ramus

13. True/False: Ultrasound of the sphenoid sinus can be performed to rule out sinusitis (infection of the sinuses).

False; CT

41. True/False: The modified Law method (axiolateral oblique) requires a tube angulation of 25 degrees caudad.

False; Modified law requires a 15° ↓

16. True/False: A Le Fort fracture produces a "free-floating" zygomatic bone.

False; the fracture and "free floating bone" occurs in the maxillae

25. True/False: The CR should be angled as needed to be parallel to the glabellomeatal line (GML) for the superoinferior tangential projection of the nasal bones.

False; ⊕ CR center to nasion and angle GAL (glabelloalveolar line) (skim glabella and anterior upper front teeth)

28. Which positioning line, if placed parallel to the image receptor, ensures adequate extension of the head for the submentovertical projection for zygomatic arches?

IOML

50. Which positioning line is parallel to the IR for the SMV projection of the skull?

IOML

30. How much CR angle is required for the AP axial projection of the zygomatic arches if the IOML is placed perpendicular to the IR? (Hint: This is the same as for an AP axial skull.)

IOML 37°; OML 30°

26. Which positioning line is placed perpendicular to the image receptor for a modified parietoacanthial projection?

LML (lips-meatal line ), OML forms 55° angle with IR

20. B. This places the ___________positioning perpendicular to the IR.

MML

19. Which plane is placed parallel to the IR with a true lateral projection of the facial bones?

MSP ‖ (parallel) , IPL ⊥, IOML ⊥

20. A. What is the angle between the OML and plane of image receptor with a parietoacanthial (Waters method) projection

OML forms a 37° angle with MML ⊥ to IR

16. Match each of the following structures to its related cranial bone. ______ 7. Foramen magnum

Occipital bone

16. Match each of the following structures to its related cranial bone. ______ 10. Lateral condylar portions

Occipital bone "lateral condylar portion=occipital condyles"

17. Which frontal projection of the facial bones best visualizes the region of the maxilla and orbits?

Parietoacanthial (Waters Method) Projection

46. Which routine projection is best for demonstrating the maxillary sinuses?

Parietoacanthial Projection (Waters Method)

31. The proper method and projection name for the "three-point landing" projection for the optic foramen is the

Rhese Method

16. Match each of the following structures to its related cranial bone. ______ 9. Zygomatic process

Temporal bone

47. Why should a horizontal CR be used for the erect PA (Caldwell) projection for sinuses rather than the usual 15-degree caudad angle?

To assess air-fluid levels accurately, CR must be horizontal, and the patient must be erect.

24. True/False: The lateral projection of the nasal bones should be performed using a small focal spot, low-to-medium kV (analog), and close collimation.

True

43. True/False: A grid is not required for the lateral projection of the nasal bones.

True

8. True/False: The hypophysis cerebri is another term for the pituitary gland.

True

9. True/False: The sphenoid bone articulates with all the other cranial bones.

True

15. True/False: Facial bone studies should be performed erect whenever possible.

True; facial bones are preferred if the PT condition allows

6. True/False: All of the paranasal sinuses are contained within cranial bones, except the maxillary sinuses.

True; the paranasal sinuses are located in the maxillary, frontal, ethmoid, and sphenoid

45. Why should a patient remain in an erect position for at least 5 minutes before sinus radiography?

allow air-fluid levels to rise and mucus to settle within the paranasal cavities

26. Match each of the following pathologic indications to the correct definition or description. B. Fracture evident by sphenoid sinus effusion

basal skull fracture

18. Which skull classifications applies to a skull with an angle of 54 degrees between the midsagittal plane and the long axis of the pars petrosa?

brachycephalic skull

10. The shallow depression just posterior to the base of the dorsum sellae and anterior to the foramen magnum is the ______.

clivus of the sphenoid bone

12. Which small section of bone is located superior to the cribriform plate?

crista galli

26. Match each of the following pathologic indications to the correct definition or description. F. Tangential view may help in determining extent or degree of this fracture

depressed fracture

19. Which of the classifications is considered an average-shaped skull?

mesocephalic → brachycephalic (short, broad, ±54°) and dolichocephalic ( long, narrow, ±40°); >47°< between petrous pyramids of the temporal bone and MSP

37. An infection of the mastoid air cells, if untreated, can lead to a serious infection of the brain that is called

encephalitis

36. The aditus is an opening between the _____and the _____portion of the temporal bone.

epitympanic recess and the mastoid portion of the temporal bone

16. Match each of the following structures to its related cranial bone. ______ 5. Perpendicular plate

ethmoid bone

16. Match each of the following structures to its related cranial bone. ______ 6. Superior nasal conchae

ethmoid bone

16. Match each of the following structures to its related cranial bone. ______ 8. Cribriform plate

ethmoid bone

34. Which structure helps equalize atmospheric pressure in the middle ear?

eustachian tube "ear poppin'"

41. 3 divisions of the ear

external→middle→internal ear

7. True/False: All of the paranasal sinuses except the sphenoid communicate with the nasal cavity.

false; All the paranasal sinus cavities communicate with one another and with the nasal cavity (fossae)

8. True/False: In general, all of the paranasal sinuses are fully developed by the age of 6 or 7 years.

false; maxillary at birth, frontal and sphenoid by 6 or 7, and ethmoid by late teens

16. Match each of the following structures to its related cranial bone. ______ 11. Superciliary arch (ridges)

frontal bone

16. Match each of the following structures to its related cranial bone. ______ 3. Glabella

frontal bone

3.6 Match each of the following definitions or characteristics to the correct facial bone. 6. Help to mix air drawn into nasal cavity

inferior nasal conchae

3.3 Match each of the following definitions or characteristics to the correct facial bone. 3. Lie just anterior and medial to the frontal process of maxilla

lacrimal bones

16. Match each of the following structures to its related cranial bone. ______ 13. Inion

occipital bone "Inio=external occipital protuberance"

26. Match each of the following pathologic indications to the correct definition or description. D. Destructive lesion with irregular margins

osteolytic neoplasm

26. Match each of the following pathologic indications to the correct definition or description. C. Condition that begins with bony destruction followed by bony repair

paget disease (osteitis deformans)

3.7 Match each of the following definitions or characteristics to the correct facial bone. 7. Possesses a vertical and horizontal portion

palatine bones

4. Which structures are found at the widest aspect of the skull?

parietal tubercles (eminences)

31. Which aspect of the temporal bone contains the organs of hearing and balance?

petrous portion (petrous pyramid or pars petrosa)

16. Match each of the following structures to its related cranial bone. ______ 1. Pterygoid hamulus

sphenoid bone

16. Match each of the following structures to its related cranial bone. ______ 14. Sella turcica

sphenoid bone

16. Match each of the following structures to its related cranial bone. ______ 2. Anterior clinoid processes

sphenoid bone

16. Match each of the following structures to its related cranial bone. ______ 4. Foramen ovale

sphenoid bone

14. What is the name of the cranial suture formed by the inferior junction of the parietals to the temporal bones?

squamosal suture

2. Which aspect of the frontal bone is thin-walled and forms the forehead?

squamous (vertical portion)

30. Which aspect of the temporal bone is considered the thinnest?

squamous portion (vulnerable to fracture)

48. Where should the petrous ridges be located (on the image) for a well-positioned, 25-degree caudad PA axial (Haas method) projection?

superior to the posterior clinoids and dorsum sellae (bilateral symmetry to indicate no rotation of skull)

15. What are the two terms for the small, irregular bones found in the adult skull sutures?

sutural or wormian

16. Match each of the following structures to its related cranial bone. ______ 12. EAM

temporal bone

7. What is the thickest and densest structure in the cranium?

temporal bone (pyramid-shaped portion)

16. Match each of the following structures to its related cranial bone. ______ 15. Petrous ridge

temporal bones

32. The correct term for the eardrum is the

tympanic membrane

46. Where is the central ray centered for a lateral projection of the cranium?

2 ½" ↑ EAM

49. Where is the central ray centered for an SMV projection of the skull?

1½" inferior to the mandibular symphysis or midway between the goinions 3/4" anterior to EAM

5. On average, how many separate cavities make up the frontal sinus?

2

6.E. List the number of individual bones that articulate with the following cranial bones. ETHMOID

2 cranial bones 1) frontal 2) sphenoid

49. Which positioning line should be perpendicular to the image receptor for the parieto-orbital oblique (Rhese method) projections for optic foramina? A. Acanthomeatal line (AML) B. Mentomeatal line (MML) C. Infraorbitomeatal line (IOML) D. Glabellomeatal line (GML)

A. Acanthomeatal line (AML) AML, rotate head 37° towards the affected side

28. Which of the following imaging modalities may be used to examine a possible cranial bleed caused by trauma? A. CT B. MRI C. Ultrasound D. Nuclear medicine

A. CT (modality of choice to differentiate between epidural and subdural hemorrhage)

44. Where is the CR centered for a lateral projection of the paranasal sinuses?

Midpoint between EAM and outer canthus (eye)

29. How much skull tilt and rotation are required for the oblique inferosuperior (tangential) projection for zygomatic arches?

Rotate head 15° toward side to be examined; also tilt chin 15° toward side of interest

37. What structures are better defined when the CR angulation is increased from 35 to 40 degrees caudad for the AP axial projection of the mandible?

TM fossae (increase in angle reduces superimposition of TM fossae and mastoid portions of the temporal bone)

42. True/False: The Schuller method requires that the skull be placed in a true lateral position.

True True Lateral (IOML ⊥), IPL ⊥, MSP ‖, CR ⊕ 25°-30° ↓, 2" ↑ EAM

43. True/False: Otosclerosis is a hereditary disease.

True (hereditary disease that involves irregular ossification of the auditory ossicles of the middle ear; 11-30 YO, Women, CT

11. What is the name of the paired collections of bone found inferior to the cribriform plate that contain numerous air cells and help form the lateral walls of the nasal cavity?

lateral labyrinth

11. Which aspect of the ethmoid bone contains the ethmoid air cells (sinuses)?

lateral labyrinths (masses)

13. What is the formal term for the left sphenoid fontanel in the adult?

left pterion

26. Match each of the following pathologic indications to the correct definition or description. E. Fracture of the skull with jagged or irregular lucent line that lies at an angle to the axis of the bone

linear fracture

3.4 Match each of the following definitions or characteristics to the correct facial bone. 4. Unpaired bone in the adult

mandible

3.1 Match each of the following definitions or characteristics to the correct facial bone. 1. Contains four processes

maxilla

39. The internal ear is divided into the osseous or bony labyrinth and the _______ labyrinth.

membranous labryinth

9. True/False: The frontal sinuses are usually larger in men than in women.

true

18. Which single projection of the facial bones best demonstrates any possible air-fluid levels in the sinuses if the patient cannot stand or sit erect?

x-table horizontal beam

3.2 Match each of the following definitions or characteristics to the correct facial bone. 2. Forms lower, outer aspect of orbit

zygomatic bone

27. Where is the CR centered for a lateral projection of the nasal bones?

½" inferior to nasion