The Skull

Question 1

The skull is composed of several separate bones united at immobile joints called:

Answer 1

Sutures

Question 2

The connective tissue between the bones:

Answer 2

Sutural ligament

Question 3

How is the mandible attached to skull?

Answer 3

Via the mobile temporomandibular joint

Question 4

The bones of the skull can be divided into the bones of the _______ and the ______

Answer 4

Cranium and face

Question 5

The _____ is the upper part of the cranium, with the _____ as the lower part.

Answer 5

Vault, base

Question 6

The bones of the skull are made up of external

and internal tables of compact bone separated by a layer of spongy bone called:

Answer 6

diploë

Question 7

Is the external or internal table more brittle and thinner?

Answer 7

Internal table

Question 8

Where are the bones of the skull covered?

Answer 8

On the outer and inner surfaces periosteum

Question 9

Where the bones of the skull meet

Answer 9

Sutures

Question 10

Bones of the skull following the lines of suture

Answer 10

Sutural bones

Question 11

There the two parietal bones intersect with the middle of the frontal bone

Answer 11

Bregma

Question 12

The superior portions of the frontal bone, occiptal bone, and parietal bones

Answer 12

Calvaria

Question 13

Opening on the back part of the parietal foramen, for parietal emissary vein (which drains into the superior sagittal sinus)

Answer 13

Parietal foramen

Question 14

Compound bone that forms the base of the cranium, behind the eye, and below the front part of the brain.

Answer 14

Sphenoid bone

Question 15

Opening for the brain stem

Answer 15

Cranial foramina

Question 16

The types of fracture to the skull depends on:

Answer 16

Age of the pt

Severity of the blow

Area of skull receiving the trauma

Question 17

A severe localized blow produces:

Answer 17

A local indentation

Often accompanied by splintering of the bone

Question 18

Blows to the vault often result in:

Answer 18

A series of linear fractures that radiate out through the thin areas of the bone

Question 19

What strongly reinforces the base of the skull, and tends to deflect linear fractures?

Answer 19

The petrous parts of the temporal bones and occipital crests

Question 20

What is the adult skull compared to? What is the young child skull compared to?

Answer 20

Adult - eggshell that has a limited resilience, beyond which it splinters

Child - ping pong ball, a localized blow produces a depression, but no splintering

Question 21

What is a “pond” fracture?

Answer 21

localized blow produces a depression without splintering in a young child

Question 22

What is the cranial fossa?

Answer 22

The inferior cavity of the skull.

Anterior, middle, and posterior regions.

Superior border of petrous part of temporal bone separates the posterior and middle

Sphenoidal crest separates the anterior and middle

Question 23

In fractures of the anterior cranial fossa, what may be damaged?

Answer 23

The cribriform plate of the ethmoid bone

Usually results in tearing of the overlying meninges

Question 24

Bleeding from the nose, resulting from fracture in the anterior cranial fossa

Answer 24

Epistaxis

Question 25

Leakage of cerebrospinal fluid into the nose, resulting from fracture of the anterior cranial fossa

Answer 25

Cerebrospinal rhinorrhea

Question 26

Fracture involving the orbital plate of the frontal bone results in:

Answer 26

Hemorrhage of beneath the conjunctiva and into the orbital cavity, causing exophthalmus

Question 27

If the frontal sinus is involved in fracture..

Answer 27

Hemorrhage in the nose

Question 28

Why are fractures in the middle cranial fossa common?

Answer 28

Because its the weakest part of the base of the skull

Question 29

What is the weakness of the middle cranial fossa caused by?

Answer 29

The numerous foramina and canals, the cavities of the middle ear and sphenoidal sinus

Question 30

In fractures of the middle cranial fossa, what is common?

Answer 30

Leakage of cerebrospinal fluid and blood from the external auditory meatus

Question 31

What nerves may be involved in a fracture of the middle cranial fossa?

Answer 31

Cranial nerves VII and VIII, since they pass through the petrous portion of the temporal bone.

Also, III IV and VI

Question 32

Cranial nerves III, IV, and VI may be damaged if:

Answer 32

The lateral wall of the cavernous sinus is torn.

Blood and CS fluid may leak into the sphenoidal sinus and into the nose.

Following a fracture of the middle cranial fossa

Question 33

In fractures of the posterior cranial fossa…

Answer 33

Blood may escape into the nape of the neck deep into the postvertebral muscles

Question 34

Days after a posterior cranial fossa fracture,…

Answer 34

The blood can black between muscles and appear in the posterior triangle, close to the mastoid process.

The mucous membrane of the roof of the nasopharynx may be torn, and blood may escape there.

Question 35

If the jugular foramen is damaged, following a posterior cranial fossa fracture, what nerves may be damaged?

Answer 35

IX, X, and XI

Question 36

Why is the hypoglossal nerve (XII) usually spared in a posterior cranial fossa fracture?

Answer 36

Because the walls of the hypoglossal nerve are strong

Question 37

Signs of facial bone fractures

Answer 37

Deformity

Ocular displacement

Abnormal movement accompanied by crepitation (crunching sounds) and malocclusion (misaligned teeth)

Question 38

The muscles of the face are thin and weak and therefore:

Answer 38

Cause little displacement of bone fragments.

Exception is a fracture mandible, because the strong muscles of mastication can cause considerable misplacement of the fractured bone

Question 39

Most common facial fractures?

Answer 39

Involve the nasal bones, zygomatic bone, and mandible

Question 40

Maxillofacial fractures occur as a result of:

Answer 40

Massive trauma

Question 41

What happens in a maxillofacial fracture?

Answer 41

There is extensive swelling of the face, midfacial mobility of underlying bone on palpation, malocclusion of the teeth, and possible leakage of cerebrospinal fluid from the nose (cerebrospinal rhinorrhea) due to fracture of the cribriform plate.

Question 42

What may happen due to orbital wall damage, following a maxillofacial fracture?

Answer 42

Double vision, diplopia

Question 43

Damage to the infraorbital nerve in fracture of the maxilla can cause:

Answer 43

Anesthesia or parasthesia of the cheek and upper gum

Blood can leak into the maxillary sinus and then leak into the nasal cavity, resulting in epistaxis

Question 44

Sites of fracture for maxillofacial are classified as:

Answer 44

Le Fort 1 - below nose, across length of mouth

Le Fort 2 - from cheek bones up over top nose to other cheek bone

Le Fort 3 - from temporal side of orbit, in between orbits, to other temporal side of opposite orbit