Skull anatomy Flashcards
The zygomatic arch is made up of which bones?
The zygomatic process of the temporal bone and the temporal process of the zygomatic bone
The walls of the cranial cavity tend to be thinnest in areas that are not covered with muscles. T/F
FThey tend to be thinnest in areas covered with muscles.
Which bone can be considered both part of the neurocranium and viscerocranium?
Ethmoid
The largest fontanelle
Anterior fontanelle
Most dynamic of our bones
Mandible
Carotid canal is found in which fossa?
Middle
At birth, the bones of the calvaria are smooth and unilaminar. T/F
T
The median point of the anterior border of the foramen magnum [Identify]
Basion
Stylomastoid foramen is found on which bone?
Temporal
What is not seen in the inferior view of the skull?
A. foramen magnum
B. foramen rotundum
C. foramen lacerum
D. foramen spinosum
B
How many bones are found in the head?
29
22 cranial bones, 6 ear bones, 1 hyoid bone
Early closure of the sutures of the skull can lead to craniosynostosis. Confluence sutures correspond to fontanelles in young skulls. Which of the following do not correspond?
a. Vertex: Anterior Fontanelle
b. Pterion: Sphenoid fontanelle
c. Asterion: Mastoid foramen
d. Lambdoid: Posterior fontanelle
A
What characteristics of the calvarium provides protection from blunt trauma forces?
A. division by sutures and fontanelles
B. supported by horizontal and vertical buttresses
C. double layer of compact bone
D. thickest in area covered by muscle
B
Which structures are used as reference for the skull’s anatomical position?
Inferior margin of the orbit, and superior margin of the external acousttic meatus opering
Carotid canal is found on which bone?
Temporal
How does the fontanelle indicate degree of hydration of an infant?
A depressed fontanelle indicates dehydration
Which covering of the skull is thinner and more brittle: internal table or external table?
Internal table.
External table has to be thicker and harder for stronger bone structure.
Scaphocephaly results from early closure of which suture?
Sagittal
This part of the skull base marks the posterior border of the middle cranial fossa
a. dorsum sella
b. tuberculum sella
c. pituitary fossa
`d. clivius
A
When does posterior fontanelle close?
2 months after birth
The mandible supports the lower teeth. True or false?
True
What is the main landmark in searching for the facial nerve?
A. buccal muscle
B. masseter
C. external acoustic meatus
D. mastoid tip
D
When does the obliteration of sutures between bones of the calvaria usually begin?
30 and 40 years on internal surface
10 years later on external surface
The facial bones compose which part of the skull?
Viscerocranium
Which bone has the greatest contribution in the upper facial skeleton?
Maxilla
Junction of coronal and sagittal sutures [Identify]
Bregma
The landmark on the skull where the frontal, sphenoidal, temporal, and parietal bones meet
.a. basion
b. opisthion
c. asterion
d. pterion
D
Which separate the anterior cranial fossa from the middle cranial fossa?
Sphenoid ridge/ posterior margin of the lesser wing of the sphenoid bone,and the anterior margin of the chiasmatic sulcus
The cribriform foramen is found in which fossa?
Anterior
The convexity of the calvaria distributes and thereby minimizes the effects of a blow to the head. T/F
T
The calvaria is composed mostly of flat bones. True or false?
True.
What is malar flush?
Redness of the skin covering the zygomatic prominence (malar eminence)
Union of mandibular bones begin at what age?
1st year
Completion of the union of the mandibular bone is at what age?
2 years old
Describe Le Fort II fractures
passes from the posterolateral parts of the maxillary sinuses superomedially through the infra-orbital foramina, lacrimals or ethmoids to the bridge of the nose. results in the separation of the entire central part of the face from the rest of the cranium
Which is not part of the temporal bone?
A. EAC
B. IAC
C. vestibular aqueduct
D. jugular foramen
D
Internal auditory hiatus is found in which fossa?
Posterior
Incisive canals are found on which bone?
Palatine process of maxilla
What is the frontal lobe landmark?
A. pterion
B. lambda
C. inion
D. asterion
A
The supraorbital fissure is found in which fossa?
Middle
Frontal suture is obliterates by what age?
8 years old
The optic canal is found in which fossa?
Middle
Cause of black eye when skin of the orbit bruises
Accumulation of tissue fluid and blood in the surrounding connective tissue, which gravitates into the superior eyelid and around the eye
How many cranial bones are there in total?
22
8 paired (16 total): Temporal, parietal, nasal, lacrimal, maxilla, palatine, inferior nasal conchae/turbinate, zygomatic
6 unpaired: Mandible, ethmoid, vomer, frontal, occipital, sphenoid
Union of the frontal bones begin at which age?
2 years old
After increasing in capacity, the calvaria increases slightly in size, as a result of bone thickening, for how long?
3-4 years
Oxycephaly or turricephally results from early closure of which suture?
Coronal
The suture that connects the parietal bones. [Identify]
Sagittal suture
Crista galli is part of which bone?
Ethmoid bone
Part of occiput that forms the main joint between the head and neck as it articulates with atlas
a. acetabulum
b. condyle
c. asterion
d. basion
B
Foramen magnum is found in which fossa?
Posterior
Condyloid canal is found on which bone?
Occipital
For how long does the calvaria increase in capacity?
15-16 years
An excavated skull showed 1 erupted tooth. how old is this?
a. 4 months
b. 8 months
c. 6 months
d. 10 months
C
The viscerocranium can also be called the spanchnocranium. True or false?
True.
The most prominent point of external occipital protruberance [Identify]
Inion
Fractures of the pterion of the skull may result to tear of the artery supplying the anterior lateral meninges causing epidural hematoma. Where does this artery pass through the skull?
A. foramen ovale
B. foramen rotundum
C. foramen spinosum
D. foramen lacerum
C
The most prominent point of the zygomatic bone [Identify]
Malar point
The anterior and posterior ethmoid fossa is found in which fossa?
Anterior
What is the opening between the greater and lesser sphenoid wings?
A. Foramen Ovale
B. Foramen rotundum
C. Superior Orbital Fissure
D. Inferior Orbital Fissure
B
When does the sphenoidal fontanelle close?
1-2 months after birth
How many bones make up the viscerocranium?
15, including the ethmoid
14, excluding the ethmoid
Which bone supports the upper teeth?
Maxilla
The suture that unites the maxillary bones [identify]
Intermaxillary suture
The volume of air spaces is directly proportional to age. True or false?
True.
The foramen cecum of the frontal bone gives passage to vessels during fetal development but is insignificant postnatally. T/F
T
Which part of the frontal bones underlie the eyebrows?
Supercilliary arches
Describe Le Fort I fractures
horizontal fractures superior to the maxillary alveolar process, crossing the bony nasal septum and possible the pterygoid plates of the sphenoid
Superior most point of the cranium [Identify]
Vertex
In life, foramen lacerum is closed by a cartilage plate. T/F
T
Permanent teeth begin to erupt at what age?
6th year
Knowing his anatomy well, an intern palpated the bone of a one month old baby. Upon palpation, he noticed the inion was as hard as a bone. Immediately he thought of early:
a. Closure of the anterior fontanelle
b. Closure of the sphenoid fontanelle
c. Closure of the posterior fontanelle
d. NOTA
C
The midline suture that results when the frontal bones fail to fuse [Identify]
Metopic suture
How does the mastoid process develop?
As it develops, the SCM pulls on the petromastoid parts of the temporal bones
How does the fontanelle indicate level of intracranial pressure?
A bulging fontanelle indicates increased pressure on the brain
How many bones comprise the neurocranium?
8, including the ethmoid
7, excluding the ethmoid
The greater and lesser palatine foramen are found on which bone?
Palatine bone
How many unpaired cranial bones are there?
6
The anterior fontanelle is bordered by:
a. Frontal, occipital
b. Parietal, occipital
c. Parietal, sphenoid
d. Frontal, parietal
D
The foramen cecum is found in which fossa?
Anterior
What do you call the remnant of the frontal suture?
A. metopic
B. bregma
C. symphisis
D. pterygoid
A
The suture where the occipital bones meet the parietal bones [Identify]
Lambdoid suture
Plagiocephaly results from early closure of which suture?
Coronal or labdoid, on one side only
Premature closing of cranial sutures usually impair brain development. T/F
F
They usually do not affect brain development.
Time of greatest increase in size of calvaria
First 2 years, the period of most rapid brain development
The 2nd division of the trigeminal nerve enters througha. foramen lacerumb. foramen rotundumc. foramen ovaled superior orbital fissure
B
Which marks the site of the posterior fontanelle in the adult cranium?
Lambda
The antrum of Highmore is also known as
A. sphenoid sinus
B. maxillary sinus
C. ethmoid sinus
D. frontal sinus
B
The thinnest wall of the orbit is not commonly the first wall fractured because:
A. the roof is supported by a horizontal buttress of the frontal bone
B. a counter-hydraulic force pushes the greater wing of the sphenoid forward
C. ethmoid air cell reinforce the medial
D. the inferior orbital fissure is supported by horizontal and vertical buttresses of facial bones
C
When does the mastoid process gradually develop?
1st year
The horizontal plane used as reference for the skull’s anatomical position is called what?
Orbitomeatal plane or Frankfort horizontal plane
What structure characterize pneumatized bones?
Air spaces (sinuses)
What are the 8 bones that compose the neurocranium?
Unpaired: frontal, occipital, sphenoid, ethmoid
Paired: temporal, parietal
Sequence of obliteration of sutures after bregma
Sagital, coronal, lambdoid
Hypoglossal foramen is found in which fossa?
Posterior
Which point overlies the anterior division of the middle meningeal artery and vein?
Pterion
The glabella is most marked in males. True or false?
True
Which structures separate the middle cranial fossa and the posterior cranial fossa?
Dorsal sellae, basal occipital and crest of petrous bone
The suture that connects the frontal bone with the parietal. [Identify]
Coronal suture
Why is the facial nerves of a newborn vulnerable to injury during delivery?
The facial nerves are close to the surface when they emerge from the stylomastoid foramina because the mastoid processes are still to develop.
Foramen rotundum, foramen ovale, foramen lacerum, and foramen spinosum and is found in which fossa?
Middle
Junction of these sutures: parietomastoid, occipitomastoid, lambdoid [Identify]
Asterion
Jugular foramen is found in which fossa?
Posterior
The basicranium is made up of irregular bones with flat portions. True or false?
True
Which are the 8 paired cranial bones?
Temporal, parietal, nasal, lacrimal, maxilla, palatine, inferior nasal conchae/turbinate, zygomatic
Tympanic canaliculus is found on which bone?
Temporal
Descrive Le Fort III fractures
horizontal fracutres that passes through the superior orbital fissures and the ethmoid and nasal bones, extending laterally thorough the greater wings of the sphenoid and frontozygomatic sutures. may result to the separation of maxillae and zygomatic bones to separate from the rest of the cranium
The mental foramen lies near the superior border of the body of the mandible as a result of bone resorption due to tooth extraction. T/F
T
As people age, the cranial bones normally become progressively thinner and lighter, or thicker and heavier?
Thinner and lighter
The point on cranium where frontonasal and internasal sutures meet [Identify]
Nasion
Which is not part of occipital bone?
A. foramen magnum
B. hypoglossal canal
C. jugular foramen
D. condyloid fossa
C
Hiatus for greater and lesser petrosal nerves found in which fossa?
Middle
Which are the 6 unpaired cranial bones?
Mandible, ethmoid, vomer, frontal, occipital, sphenoid
Extraction of teeth causes the alveolar bone to resorb in the affected regions. T/F
T
Flat bones are formed by endochondrial ossification. True or false?
False.
They are formed by intramembranous ossification.
The frontal suture divides the frontal bones of an adult cranium. True or false?
False.
It divides the fetal cranium.
Premature closure of cranial sutures
Primary craniosynostosis
Mastoid canaliculus is found on which bone?
Temporal
Which marks the site of the anterior fontanelle in the adult cranium?
Bregma
Bones with air spaces are called what?
Pneumatized bones
When does the mastoid fontanelle close?
1-2 months after birth
What are the 15 bones that compose the viscerocranium?
Unpaired: ethmoid, mandible, vomer
Paired: nasal, lacrimal, maxilla, zygomatic, inferior nasal conchae/turbinate, palatine
Not included in the pterion
A. Lesser wing of the sphenoid
B. Squamous part of temporal bone
C. Frontal
D. Parietal
A
Which of the following is a part of the mandible?
a. Coracoid process
b. Coronoid process
c. Uncinate Process
d. Calcaneal Process
B
The neurocranium can be divided into two parts, based on region. What are they?
Calvaria/ skull cap and basicranium/cranial base
Which bones meet at the pterion?
frontal, parietal, temporal and sphenoid
Soft spot on a new born’s skull?
Fontanelle
The point where the frontal, parietal, temporal and sphenoid bones meet?
Pterion
The splanchnocranium and the dermatocranium are formed through the same type of ossification. True or false?
False.
Splanchnocranium is by endochondrial ossification. Dermatocranium is by intermembranous ossification.
Concurrent enlargement of the frontal and facial regions is associated with the increase in size of which sinuses?
Paranasal sinuses
The anterior fontanelle closes at which age?
18 months
Tympanomastoid fissure is found on which bone?
Temporal
The chondocranium is formed by intramembranous ossification. True or false?
False.It is formed by endochondrial ossification.
In the 2008 Beijing Olympics, a 20-year old woman was hit on the right side of the head. After the event she complained of nausea, vomitting and eventually was rushed unconscious to the hospital. What could be the problem? a. Fracture of the temporal bone b. Fracture of the parietal bone c. Fracture of the sphenoid bone d. Any of the above
A
Known as the cheek bones [Identify]
Zygomatic bone
An incidental finding in a skull X-ray showed a vertical fracture line dividing the frontal bone even without history of head trauma. Which of the following may be true? A. The sagittal suture is extended anteriorly. B. The frontal sinus septum is mistaken for a fracture. C. There is a persistent metopic suture. D. The vertical line is the shadow of the lambdoid suture.
C
The most posterior point of the sagittal plane of the skull [Identify]
Opistocranion
The smooth slightly depressed area between the supercilliary arches. [Identify]
Glabella
Junction of the lambdoid suture and sagittal suture [Identify]
Lambda
The dermatocranium is formed by endochondrial ossification. True or false?
False.
It is formed by intramembranous ossification.
Which bones are pneumatized bones?
Frontal, temporal, sphenoid, ethmoid
What is the most frequently fractured facial bone?
a. zygomatic bone
b. nasal bone
c. mandible d. temporal
B
The most frequently fractured facial bone is the nasal bone, the most frequently fractured bone is the clavicle.
Variants of fractures of the maxillae classified by Leon-Clement Le Fort
Le Fort I, Le Fort II and Le Fort III fractures
