Anatomy Exam Bones of the Cranial Vault 4 — Questions and Answers
Question 1: Craniosynostosis of the sagittal suture most commonly produces which skull shape?
- Brachycephaly (wide, short skull)
- Scaphocephaly (long, narrow skull) (Correct answer)
- Plagiocephaly (asymmetric skull)
- Trigonocephaly (triangular skull)
Correct answer: Scaphocephaly (long, narrow skull)
Premature fusion of the sagittal suture restricts lateral growth, forcing the skull to elongate anteroposteriorly, producing scaphocephaly.
Question 2: Which groove on the inner surface of the occipital bone lodges the transverse sinus?
- Sigmoid sulcus
- Cavernous sinus groove
- Transverse sulcus (Correct answer)
- Occipital sulcus
Correct answer: Transverse sulcus
The transverse sulcus is the horizontal groove on the inner surface of the occipital bone that houses the transverse venous sinus.
Question 3: The frontal bone develops from how many primary ossification centers?
- One
- Two (Correct answer)
- Three
- Four
Correct answer: Two
The frontal bone develops from two ossification centers, one for each half, which normally fuse by age 6–8; failure to fuse leaves a metopic suture.
Question 4: Which part of the sphenoid bone contributes to the cranial vault's roof?
- Greater wings (Correct answer)
- Lesser wings
- Pterygoid plates
- Body
Correct answer: Greater wings
The greater wings of the sphenoid bone form part of the lateral walls and floor of the cranial vault, contributing to the temporal fossa.
Question 5: Wormian (sutural) bones are most commonly found near which suture?
- Coronal suture
- Metopic suture
- Lambdoid suture (Correct answer)
- Squamous suture
Correct answer: Lambdoid suture
Wormian bones are small, irregular accessory ossicles most frequently found within the lambdoid suture, though they can occur in any suture.
Question 6: The inner surface of the calvaria is lined by which layer?
- Periosteum (endosteum)
- Dura mater (endosteal layer) (Correct answer)
- Arachnoid mater
- Pia mater
Correct answer: Dura mater (endosteal layer)
The inner table of the calvaria is lined by the endosteal layer of the dura mater, which serves as the periosteum for the inner skull surface.
Question 7: Which cranial bone contains the mastoid air cells?
- Occipital bone
- Sphenoid bone
- Parietal bone
- Temporal bone (Correct answer)
Correct answer: Temporal bone
The mastoid process of the temporal bone contains the mastoid air cells, which communicate with the middle ear cavity.
Anatomy Exam Bones of the Cranial Vault 4
Craniosynostosis of the sagittal suture most commonly produces which skull shape?